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The quayside container crane (QCC) scale models for seismic simulation test on vibration tables are often high, and the model size and QCC structural size differences introduce discrepancies into the QCC model. In this investigation, discrepancies in the QCC scale model were solved using the similarity method for the sectional radius of inertia. Firstly, a governing equation for the beam section size was established. Secondly, a scale model was constructed for the shake table test, and the results were compared with the simulations. It is demonstrated that the experimental results were close to the simulations. Specifically, the acceleration, strain extreme values, and the time of occurrence were similar at different QCC points. This reveals that the shake table test of the QCC scale model can approximately reflect the prototype seismic response, which verifies the feasibility of the model design method. [ABSTRACT FROM AUTHOR]

This paper presents the details of shaking table tests on a seismic-resistant cob structure. The seismic resistance of the model was increased using bamboo strips and steel wire mesh. A one-third scale model of a prototype cob building was used to observe its dynamic performance using a shaking table. The model was subjected to different levels of acceleration time history record of the 1940 El Centro earthquake. These levels were varied from 25% (R25) to 200% (R200) in increment of 25%. The data of acceleration of both the in-plane and out-of-plane loaded walls and displacement of the model were recorded. The damage to the model began with the appearance of cracks in the in-plane loaded wall at R100 level of dynamic excitation that changed the structure's dynamic characteristics. The size and numbers of cracks increased in the walls of the model with increased levels of peak ground acceleration (PGA) and the structure became heavily damaged at R200 level of test run. The acceleration response and its amplification were higher for the in-plane loaded wall as compared to the out-of-plane loaded wall. The maximum acceleration for the in-plane and out-of-plane loaded walls was recorded as 0.65 g and 0.57 g, respectively, in the prototype domain. The torsion effects caused unequal structure displacement at its east and west ends at roof level. The energy dissipation of the wall continued until the end of testing. The observed structural damages corresponded to four performance levels that were correlated with the damage limit states. [ABSTRACT FROM AUTHOR]

This paper presents results from a series of 1g shaking table tests on seismic deformation behaviour of segmental geogrid reinforced soil walls using multiple reinforcement stiffness along the wall. The reinforcement stiffness arrangement along the wall height was uniform, alternating and grouped schemes. During the experimental program, digital image analysis technique was employed to capture the failure mechanism and distribution of shear strains in the backfill. It was found that the facing wall deformation strongly depends on the reinforcement stiffness arrangement. The deformation of the models consisted of overturning, sliding, and bulging. By constructing walls with alternating reinforcement stiffness, similar deformation behaviour compared to uniform reinforcement stiffness was observed. However, placing weak reinforcement stiffness either in the upper half or lower half of the wall height, large deformation occurred in these locations, and bulging deformation was observed. The shear strains were also dependent on the reinforcement arrangement prior to critical acceleration. The highest values of shear strains were observed in walls constructed in a grouped arrangement. [ABSTRACT FROM AUTHOR]

To assure seismic isolation performance against design and beyond design basis earthquakes in the nuclear facility components, the lead inserted small-sized laminated rubber bearings (LRB), which has a 10 kN vertical design load, have been designed and quasi-statically tested to validate their design mechanical properties in previous studies. Following this study, the seismic shaking tests of these full-scale LRBs are performed and discussed in this paper with the dummy mass system to investigate actual seismic isolation performance, dynamic characteristics of LRBs, consistency of the LRB's quality, and so on. To study the seismic isolation performance, three beam structures (S1–S3) with different natural frequencies were installed both on the shaking table and the dummy mass supported by four LRBs: (1) S1: structure close to seismic isolation frequency; (2) S2: structure close to peak input spectral frequency; (3) S3: structure in the high-frequency region. The test results are described in various seismic levels of OBE (Operating Basis Earthquake), SSE (Safe Shutdown Earthquake), and BDBE (Beyond Design Basis Earthquake), and are compared with the analysis results to assure the seismic isolation performance and the LRB's design parameters. From the results of the shaking table tests, it is confirmed that the lead inserted small-sized LRBs reveal an adequate seismic isolation performance and their dynamic characteristics as intended in the LRB design. [ABSTRACT FROM AUTHOR]

In this study, four single-story reinforced masonry shear walls (RMSWs) (two prefabricated and two cast-in-place) under reversed cyclic loading were tested to evaluate their seismic performance. The aim of the study was to evaluate the shear behavior of RMSWs with flanges at the wall ends as well as the effect of construction method. The test results showed that all specimens had a similar failure mode with diagonal cracking. However, the crack distribution was strongly influenced by the construction method. The lateral capacity of the prefabricated walls was 12% and 27% higher than that of the corresponding cast-in-place walls with respect to the rectangular and T-shaped cross sections. The prefabricated walls showed better post-cracking performance than did the cast-in-place wall. The secant stiffness of all the walls decreased rapidly to approximately 63% of the initial stiffness when the first major diagonal crack was observed. The idealized equivalent elastic-plastic system showed that the prefabricated walls had a greater displacement ductility of 3.2–4.8 than that of the cast-in-place walls with a displacement ductility value of 2.3–2.7. This proved that the vertical joints in prefabricated RMSWs enhanced the seismic performance of walls in shear capacity and ductility. In addition, the equivalent viscous damping of the specimens ranged from 0.13 to 0.26 for prefabricated and cast-in-place walls, respectively. [ABSTRACT FROM AUTHOR]

The combined retaining structure has gradually received considerable attention in the slope engineering, due to its good reinforcement effects. However, most of the published research studies were focused on the seismic responses of the single-formal supporting structure only. The investigations of dynamic responses of the combined retaining structures are scarce, and the current seismic design is conducted mainly based on experiences. In this work, a series of large-scale shaking table tests were conducted to investigate the seismic responses of the combined retaining structures (i.e., prestressed anchor cables and double-row antisliding piles) and the reinforced slope under seismic excitations, including amplification effect of internal and surface acceleration of the reinforced slope, distribution and change of prestress of the anchor cable, dynamic response of soil pressure behind the antislide pile, and horizontal displacement of the reinforced slope surface. Test results show that, supported by the reinforcement of composite support system, the slope with the multilayer weak sliding surface can experience strong ground motion of 0.9 g. The load of the antisliding pile has reached 80% of its bearing capacity, and the load of the anchor cable has reached 75.0% of its bearing capacity. When the seismic intensity reaches 0.5 g, the slope surface has an obvious downward trend, which will make the corresponding soil pressure suddenly increase after the antislide pile. At the potential sliding zone, the axial force of the anchor cable will increase suddenly under the action of earthquake; after the earthquake, the initial prestress of the anchor cable will be lost, with the loss range of 17.0%∼23.0%. These test results would provide an important reference for the further study of the seismic performance of such composite support structure. [ABSTRACT FROM AUTHOR]

We make trial binary forecasts for the Kurile–Japan subduction zone for the period 1988–2014 by hypothesizing that seismic quiescence (i.e., the absence of earthquakes of M ≥ 5 for a minimum period of Tq) is a precursor of a large (7.5 ≤ Mw < 8.5) earthquake in the coming period Ta within a radius R of the quiescence. We evaluate the receiver-operating-characteristic diagram constructed using a range of forecast models specified by (Tq, R, Ta). A forecast experiment targeting eight large earthquakes in the studied spacetime suggests that the risk of a large earthquake is modestly (probability gain G ~ 2) but significantly (p-value less than 5%) heightened for several years following a long quiescent period of Tq ≥ 9 years, within several tens of kilometers of the quiescence. We then attempt cross-validation, where we use half the data for training [i.e., optimization of (Tq, R, Ta)] and the remaining half for evaluation. With only four target earthquakes available for evaluation of the forecasts in each of the learning and evaluation periods, our forecast scheme did not pass the cross-validation test (with a criterion that the p-value is less than 5%). Hence, we cannot formally deny the possibility that our positive results for the overall period are a ghost arising from over-fitting. However, through detailed comparison of optimal models in the overall test with those in the cross-validation tests, we argue that severe over-fitting is unlikely involved for the modest G of ~ 2 obtained in the overall test. There is thus a reasonable chance that the presently tested type of quiescence will pass the cross-validation test when more target earthquakes become available in the near future. In the meantime, we find that G improves to ~ 5 when target earthquakes are limited to 8 ≤ Mw < 8.5, though we cannot say anything about the possible involvement of over-fitting because we have only three such very large target earthquakes. [ABSTRACT FROM AUTHOR]

Since the composition and stress state of thermal-insulation composite plates are extremely complex, it is difficult to conduct calculation using conventional methods. Further calculation on its composition structure is even more difficult. To settle this difficulty, this paper conducted experimental investigations on thermal-insulation composite plate and conventional composite plates, and a simplified calculation method with improved factors was deduced based on the experimental results. In this study, the influence of nonstructural thermal insulation system on the composite plate was specially considered. The calculated expressions are deduced, while the stiffness and damping (properties) are determined. Case analysis was carried out to validate the reliability and accuracy of the simplified calculation method of improvement factor. The research results indicate that the modeling difficulty and computational effort are greatly reduced, with relatively small errors. Hence, it is beneficial to the calculation and analysis of composite plates and global structures. [ABSTRACT FROM AUTHOR]

In this study, a field survey was conducted on the fixed anchorages of the operation and power generation facilities installed in domestic power plants. A static/dynamic performance evaluation was conducted to present safety evaluation guidelines that meet the domestic seismic performance requirements. Seismic performance tests were performed on the post-installed set anchors M10 and M12, which are mainly used for anchorages in accordance with the US and European seismic performance standards. The dynamic shear test results showed that the M12 anchor met the seismic performance verification criterion, whereas the M10 anchor did not because its dynamic performance was reduced, owing to the cyclic loading. In the results of the dynamic pull-out test, M12 also met the seismic performance verification criterion, whereas M10 was safe only in a non-cracked state. In summary, the seismic performance of M12 in both cracks and non-cracks was satisfied, but, in the case of M10, the results were not satisfied in cracks. This was an experimental study; it will be necessary to conduct additional analytical research in the future to verify the reliability and parameters of the experiment. [ABSTRACT FROM AUTHOR]

Underground utility tunnels are the most fundamental and reliable lifeline network in urban cities, and are widely constructed throughout the world. In urban areas, most utility tunnels usually encounter the non-homogeneity of subsoil condition due to various construction effects. Studies have shown that the damage mechanism of shallow underground structures mainly depends on the inhomogeneity of the subsoil conditions. This would become a considerable factor for the stability of the underground utility tunnel structures. However, this type of research still needs to establish the vulnerable seismic design. In this study, a series of shaking table tests were conducted on non-homogenous soils to investigate the performance of seismic interaction between utility tunnels, surrounding soils and interior pipelines. The dynamic responses measured from the test account for the boundary condition of non-homogeneous soils, the internal forces, displacement of tunnel joints, the dynamic characteristics on interior pipelines and the reasonable spring stiffness with damping in the seismically isolated gas pipeline model inside the tunnel. The vulnerability of underground utility tunnel in non-homogeneous soil zone and the mechanism of the stability of interior facilities are the main topics discussed in this paper. [ABSTRACT FROM AUTHOR]

The precise location of the seismic source of 1755 CE Great Lisbon earthquake is still uncertain. The aim of this work is to use an onland sedimentary record in southern Portugal to test and validate seismic sources for the earthquake. To achieve this, tsunami deposit thicknesses from over 150 cores collected at Salgados in southern Portugal were compared to the results of a tsunami sediment transport model (Delft3D‐FLOW) that simulates tsunami propagation, inundation, erosion, and deposition. Five different hypothetical seismic sources were modeled with varying bed roughness coefficients to assess how well they reproduced observed patterns of tsunami deposit thicknesses and dune. Modeled and observed historical tsunami arrival times were also used to test different earthquake sources. Based on these comparisons, three modeled earthquake sources were able to reproduce the observed data, suggesting they should be regarded as somewhat more likely sources for the 1755 earthquake in contrast to four other modeled sources. The fault closest to shore (Marquês de Pombal) yielded the best correlations between model and observations. Plain Language Summary: The precise location of the seismic source of 1755 CE Great Lisbon earthquake is still uncertain. The aim of this work is to use an onland sedimentary record in southern Portugal to test and validate seismic sources for the earthquake. To achieve this, tsunami deposit thicknesses from over 150 cores collected at Salgados in southern Portugal were compared to the results of a tsunami sediment transport model (Delft3D‐FLOW) that simulates tsunami propagation, inundation, erosion, and deposition. Seven different hypothetical seismic sources were modeled with varying bed roughness coefficients to assess how well they reproduced observed patterns of tsunami deposit thicknesses and dune. Modeled and observed historical tsunami arrival times were also used to test different earthquake sources. Based on these comparisons, three modeled earthquake sources were able to reproduce the observed data, suggesting they should be regarded as most likely sources for the 1755 earthquake in contrast to four other modeled sources. The fault closest to shore (Marquês de Pombal) yielded the best correlations between model and observations Key Points: 1755 CE epicenter assessment based in geological data and sediment transport modelingInnovative combination of historical, geological, and modeling dataContribution for hazard assessment in Iberia [ABSTRACT FROM AUTHOR]

A series of shaking table tests will be carried out on 0.4 m high instrumented soil nailed embankments. The important parameters considered in this study consist of a combination of three different slope angles (β = 30°, 45°, and 60°), three different nail inclinations (i = 0°, 15°, and 30°), and three nail lengths (l = 0.2, 0.3, and 0.4 m). This study revealed that the effect of slope angle on the seismic resistance of steep nailed soil slopes was significant and the minimal magnitude of the facing displacement was obtained with nail inclinations of 0° and 15° for the nailed slopes without facing and with facing, respectively. A model nailed slope with a nail inclination of 15° provided better reinforcement action than the horizontally and 30° inclined nails when stabilizing soil slopes. The maximum axial nail force was obtained at approximately two-thirds of the nail length in the model slopes with facing and at the slope facing for model slopes without facing. [ABSTRACT FROM AUTHOR]

Hinged truss with buckling‐restrained braces at base (HTBB) is composed of a rocking steel braced frame system and two replaceable all‐steel buckling‐restrained braces (BRBs) installed symmetrically on both sides at the bottom of the rocking steel braced frame. BRBs are used as hysteretic energy‐dissipating devices and damage is concentrated in BRBs. The rocking steel braced frame remains in an elastic state to control the deformation mode of the structure. Pseudodynamic testing and quasi‐static testing were conducted on a 1/3‐scale HTBB test specimen to investigate its seismic performance. The test program also includes the retrofitting process and replacement process. Pseudodynamic testing revealed that the HTBB effectively controlled the deformation pattern. The quasi‐static cyclic testing demonstrated that the system behaved in a ductile and stable manner with no strength degradation, even up to 2.5% roof drift. The damage was concentrated in the BRBs, and no damage to the hinged truss was observed throughout the testing. The failure was governed by the fracture of the BRBs. The effectiveness of the displacement‐controlled retrofitting solutions was verified and the function of the test specimen can be restored by replacing the damaged BRBs, which indicated that HTBB belongs to a resilient structural system. Finally, a finite‐element model was developed to simulate the seismic response of the test specimen. Comparisons showed good agreement between the numerical results and the pseudodynamic test results. [ABSTRACT FROM AUTHOR]

Conventional pattern recognition methods directly use 1D poststack data or 2D prestack data for the statistical pattern recognition of fault and fracture network, thereby ignoring the spatial structure information in 3D seismic data. As a result, the generated fault and fracture network is not distinguishable and has poor continuity. In this paper, a fault and fracture network characterization method based on 3D convolutional autoencoder is proposed. First, in the autoencoder training frame, 3D prestack data are used as input, and the 3D convolution operation is used to mine the spatial structure information to the maximum and gradually reduce the spatial dimension of the input. Then, the residual network is used to recover the input's details and the corresponding spatial dimension. Lastly, the hidden features extracted by the encoders are recognized via k -means, SOM, and two-step clustering analysis. The validity of the method is verified by testing the seismic simulation data and applying real seismic data. The 3D convolution can directly process the seismic data and maximize the prestack texture attributes and spatial structure information provided by 3D seismic data without dimensionality reduction and other preprocessing operations. The interleaving convolution layer and residual block overcome low learning and accuracy rates due to the deepening of networks. [ABSTRACT FROM AUTHOR]

The research objective of this study was the seismic performance of double-row reinforced ceramsite concrete sandwich wall panels. The feasibility of upgrading a new wall panel from a non-load-bearing partition wall to a load-bearing seismic wall was examined by conducting cyclic load tests on five wall panel specimens. The test piece was a sandwich thermal insulation structure that could achieve a good protection distance between the thermal insulation material and the fire source so that the fire prevention problem could be solved. At the same time, the problem of easy fall-off of the insulation system was also solved. The specimens were divided into three groups, including three double-row reinforced ceramsite concrete sandwich wall panels with different dosages of alkali-resistant glass fiber, a double-row reinforced ordinary concrete sandwich wall panel, and a solid concrete ceramic wallboard. The effects of different dosages of alkali-resistant glass fiber, construction forms, and bearing side plate materials on the seismic performance of the sandwich wall panels were investigated separately for the specimens. From the analysis of the specimen results (damage characteristics, hysteresis curves, energy dissipation capacity, bearing capacity, ductility, longitudinal reinforcement strain, and stiffness degradation), it could be seen that among the five types of wallboard, the double-row reinforced ceramsite concrete sandwich wall panel with 0.3% fiber content had the best ductility and energy dissipation capacity. Adding fiber could solve or improve the problem of the low ultimate bearing capacity of ceramsite concrete as the wallboard's bearing material. Compared with the same size solid ordinary concrete wallboard, the bearing capacity of the double-row reinforced ceramic concrete sandwich panel was slightly reduced. However, the additional seismic performance indexes were relatively superior. Through the analysis of the test results, it was shown that, when considering the thermal performance and seismic capacity, the new wall panel had good prospects for engineering applications. [ABSTRACT FROM AUTHOR]

The 1 : 8 model of turbo-generator vibration isolated foundation of common islands in nuclear plants was established for vibration characteristic tests and pseudodynamic experiments. The finite element model was established by SeismoStruct for time-history analysis. Frequencies, modal shapes and seismic responses, deformation curves, and spring deformations were compared and analyzed. Results from tests and experiments show that the natural frequencies of spring vibration isolation foundation are lower than those of common frame foundations and the vertical frequencies are far from the working disturbance frequency of the turbo-generator units. The spring vibration isolation device can reduce the acceleration response of the TG (turbo-generator) deck and redistribute the horizontal earthquake action of the foundation according to the stiffness to give full play to the seismic capacity of the columns. The errors of natural vibration frequencies and maximum seismic response are approximately 15% and 10%, respectively, and the simulation results are in good agreement with the test and experiment data. The proportion and distribution of spring deformation are close, and the test study shows the convenient and precise realization of the simulation. Results of seismic experiments and numerical simulations show that the foundation design meets the standard of the "Code for Seismic Design of Buildings" in China, which realizes the goal of spring vibration isolation and seismic resistance. The foundation design is also reasonable, safe, and reliable. [ABSTRACT FROM AUTHOR]

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A tunnel driven in loess soil in an earthquake-prone area may be subject to a variety of other external actions. Considering the coupling effect of earthquake activity, rainfall seepage and traffic movement, a dynamic model of a two-lane tunnel driven in a loess soil and a model of rain seepage are established. Using near-field pulse earthquake excitation, the influences of tunnel driven in a loess soil seepage, traffic load and earthquake activity on the dynamic responses of tunnel driven in a loess soil are studied. The variation laws of the first principal stress, the third principal stress, the displacement, the acceleration and the pore water pressure of tunnel driven in a loess soil with different rainfall amounts and burial depths are discussed. Considering the unfavorable conditions of El-Centro ground motion and rainfall seepage, the ground motion response rule of loess tunnel is studied based on the 1/40 shaking table model of loess tunnel. The results show that, at the same burial depth, the stress, displacement and pore water pressure increase with the rainfall amount; for different burial depths, according to the extreme value of the stress, displacement and the pore water pressure, the locations of antiseismic reinforcement measures are determined. The research results can provide a reference for the design and construction of tunnel driven in a loess soils under complex stress coupling. [ABSTRACT FROM AUTHOR]

Featured Application: This study considers the seismic response of a container crane subjected to near-field and far-field ground motions by a shaking table test on a 1/20 scale crane model. The results are presented focusing on the comparison of the seismic response of the container crane in terms of the maximum internal forces in the landside and seaside legs, the maximum portal drift, and acceleration when subjected to near-field and far-field ground motions. In this study, the seismic response of a container crane under near-field and far-field ground motions was investigated using a shaking table test on a 1/20 scale crane. The 1/20 scale crane was designed and fabricated based on the similitude laws, in which three independent quantities: geometric length, acceleration, and elastic modulus, were used to design the 1/20 scale crane. A series of shaking table tests were conducted at the Seismic Research and Test Center, Pusan National University, Yangsan Campus to evaluate the seismic response of the scale crane under near-field and far-field ground motions. The results show that the near-field ground motions can cause larger internal forces (that is, axial force and two bending moments) in the landside and seaside legs and larger portal drift than the far-field ground motions. The portal drift of the container crane subjected to the near-field ground motions was 43% higher than that of the container crane subjected to the far-field ground motions. Furthermore, when subjected to the near-field ground motion, the bending moment in the crane's portal leg was 37% higher than the bending moment when the crane was subjected to the far-field ground motions. [ABSTRACT FROM AUTHOR]

From our investigation of the experimental seismic response of post-and-beam wooden buildings with different column joints, we developed a nonlinear three-dimensional distinct element model that is capable of time-history response analysis. This model succeeded in predicting the seismic response of the column-base, such as rocking behavior, which has been difficult. Four types of full-scale post-and-beam wooden structures with various column-base systems were tested on a shaking table with three ground-motion sequences for each type of structure, and their response and performance were investigated. By comparing the model's predictions with the test results, we confirmed the rocking–tracking accuracy of the analysis program. The numerical model was reasonably able to keep pace with the measured experimental response in terms of load-deformation curves, following uplifts and pull-out behavior as observed at the column bottoms in the shake-table tests. The model was also able to predict maximum response acceleration and global interstory drift within 10% accuracy on average. Considering the large uncertainties associated with seismic-collapse predictions, such as complicated nonlinear behavior in frames and joints, these results encourage researchers and designers to understand how these structures respond to earthquakes and how to analyze these structures. [ABSTRACT FROM AUTHOR]

This study aimed to illustrate the seismic response and instability process of a double-row anti-slide pile-reinforced bridge foundation and gravel landslide. Selecting the gravel slope of Jiuzhai Valley along the under-construction Chengdu-Lanzhou high-speed railway as the site prototype, large-scale shaking table tests were first conducted at a similitude ratio of 1:70, with sine waves and El Centro waves as the seismic wave inputs. The amplitudes of the input seismic waves were increased, while the acceleration, dynamic earth pressure, and strain distribution were monitored in the gravel landslide. The dynamic response patterns of anti-slide pile-reinforced bridge foundations in gravel landslides were illustrated. The front-row and back-row anti-slide piles should be a reasonable distance from the bridge foundation. The response acceleration manifested an elevation amplification effect with an increasing elevation in the slope behind the anti-slide piles. Back-row anti-slide piles reinforcing the bridge foundation can reduce the effect of landslide thrust on the bridge foundation and maintain a uniform distribution of earth pressure behind the bridge foundation, mitigating seismic effects. The dynamic earth pressure peaked at the top of the bridge foundation and then decreased along the depth. The back-row anti-slide piles displayed greater resonance coupling and unloading effects before and after reaching the load-carrying limit, respectively. In seismic strengthening design involving bridge foundations and gravel landslides, when the earthquake-induced resonance coupling effect on inclined, loosely packed land masses is fully considered, pre-reinforcement measures (e.g., high-pressure grouting and anchor spraying) should be carried out on the gravel slopes. [ABSTRACT FROM AUTHOR]

Summary: This paper presents an investigation of the effects of the duration of earthquake ground motion on the peak displacement and total dissipated cumulative energy in seismic isolation systems designed by the procedures of ASCE/SEI 7‐16. The seismic isolation systems considered in this study are elastomeric with lead and natural rubber bearings and sliding in the form of single and triple friction pendulum bearings. Long‐ and short‐duration ground motions were selected so that the 5%‐damped spectral acceleration values of each motion were closely matched over periods of 0.05 to 6 s. The results of the analysis demonstrate that the duration of ground motions have insignificant effects on the isolation system peak displacement—particularly in the lower bound conditions and sliding isolation bearings—but have important effects on the total cumulative energy for all conditions. This has implications in the testing of isolators, which are presented in an evaluation of the isolator test procedures of the ASCE/SEI 7‐16 standard. The evaluation reveals that, if the cumulative energy dissipated by the isolation system is used as the controlling criterion, the specified tests are generally appropriate for locations characterized by short‐duration ground motions, but are unconservative for locations where long‐duration motions are anticipated. Additional results and discussion demonstrate that the cumulative energy may not be an appropriate criterion for designing isolator tests as it may lead to unrealistic demands on the tested isolators. [ABSTRACT FROM AUTHOR]

To study the dynamic response and spectrum characteristics of the three-dimensional crossing tunnel under the action of seismic load, we established a 1/50 downscale model based on a typical of the oblique overlapped tunnel and conducted a series of shaking table tests. Through examining the recorded dynamic responses (acceleration and dynamic strain measured at different locations in model tunnels), we found that the seismic response of the crown was the largest at the central section, and the invert of the tunnels was exactly opposite to the crown, which presented a "parabolic" distribution, and we inferred that the damage within the model may be mainly concentrated on the crown of the tunnels. Additionally, the dynamic strain showed obvious nonlinear and nonstationary characteristics under the action of different degrees of seismic intensities. Different from a single tunnel, the acceleration superposition effect appears in the cross section of two tunnels because of the spatial effect of overlapping tunnels, resulting in the obvious seismic response in the cross section. Meanwhile, we also found that the 1st dominant frequency (0.1–6.26 Hz) seismic wave played a leading role in the process of tunnel slope failure. Furthermore, the analysis of the acceleration response spectrum also showed that the surrounding rock mass has an amplification effect on low-frequency seismic waves. These results help us better understand the features of the dynamic responses and also provide evidence to reinforce the overlapped tunnels against earthquakes. [ABSTRACT FROM AUTHOR]

This paper presents the seismic dynamic response and spectrum characteristics of an orthogonal overlapped tunnel by shaking table tests. First, a prototype of the engineering and shaking table test device, which was used to design details of the experiment, was developed. Then, the sensors used in the test were selected, and the measurement points were arranged. Subsequently, the Wenchuan seismic wave with horizontal direction in different peak ground accelerations was inputted into the model, followed by a short analysis of the seismic response of the overlapped tunnel in the shaking table test as well as the distribution of the peak acceleration. Throughout the studies, the model exhibited obvious deformation stages during the seismic wave loading process, which can be divided into elastic, plastic, plastic enhancement, and failure stage. In particular, the time- and frequency-domain characteristics of the key parts of the tunnel were discussed in detail by using the continuous wavelet transform (CWT) based on the Morlet wavelet as the basis function. We found that the acceleration response was more intense within 25–60 s after the seismic wave was inputted. Furthermore, owing to "the superposition effect," the seismic response at the crown of the under-crossing tunnel was stronger than that at the invert of the upper-span tunnel. The low and medium frequencies in the transformation of small scales (5–20) significantly affected the overlapped tunnel. These results elucidate the seismic dynamic response of the overlapped tunnel and provide guidance for the design of stabilizing structures for reinforcing tunnels against earthquakes. [ABSTRACT FROM AUTHOR]

We tested the capability of seismic noise to monitor the stability conditions of a small rock block that we forced to fail in four following stages. Ambient vibrations were recorded with a broad-band 3C seismometer placed on top of the block and were processed to analyse their spectral and polarization characteristics with diverse algorithms. To analyse the spectral content of the records, we applied the multitaper method while seismic noise polarization features were investigated by means of the singular value decomposition of the Hermitian spectral density matrix. Numerical modelling was found to add limited value because of the uncertainty in estimating correctly spatial and mechanical features of the rock bridges between the block and the rock mass. Nevertheless, a modelling exercise we performed is in agreement with previous post-failure observations according to which unstable rocks may be coupled to the stable rock mass by rock bridges covering only a few per cent of the total surface of the fractures. Our analyses confirm that, when approaching final collapse, there is a trend of the block eigenmodes towards lower frequencies and show that polarized bands become narrower. [ABSTRACT FROM AUTHOR]

Rammed earth wall load-bearing dwellings are widely distributed in western China. Rammed earth has the advantages of warm in winter and cool in summer, and it is a kind of sustainable construction material. In recent years, in previous earthquakes, the collapse of rammed earth buildings is serious, resulting in huge losses of personnel and property. To improve the seismic performance of rammed earth buildings and retain the characteristics of local buildings, a reinforcement measure with additional structural columns is proposed in this article. Three kinds of structural columns are designed, which are cast-in-place concrete, square steel tube, and concrete-filled square steel tube core column. Through the quasi-static experimental study on the rammed earth wall, the effects of different structural columns on the failure shape, bearing capacity, deformation capacity, and energy dissipation capacity of the wall are compared. The test results show that adding structural columns on both sides of the wall can effectively restrain the rammed earth wall, restrain its brittle failure, significantly improve the energy dissipation capacity of the wall, and obviously improve the seismic performance of the wall. This measure is applicable to rammed earth buildings and provides theoretical support for improving the seismic performance of traditional dwellings. [ABSTRACT FROM AUTHOR]

The effective force testing is a promising seismic testing method for evaluating the structural dynamic response to earthquakes for conciseness and efficiency. However, two challenging loading issues are associated with this method, i.e. the natural velocity feedback (NVF) and nonlinearities related to the interaction between the loading system and specimen, thereby hindering its development and extensive applications. To address these issues, this study proposes a dynamic force loading strategy using a hybrid algorithm with linear compensation for NVF and model reference adaptive control via the minimal control synthesis (MCS) method. Online identification of linear compensation gain in preliminary tests is conceived based on the gradient descent method. A series of numerical simulations on a nonlinear loading system model with linear/trilinear single/two degree(s)-of-freedom specimens are conducted using five loading strategies, including linear and nonlinear compensations and MCS method. Comparative studies show that the proposed method and nonlinear compensation strategy outperform the other three methods, and sometimes the proposed method performs best. In summary, the proposed method is promising because of its accuracy and robustness as well as its ease of implementation and cost-effectiveness. [ABSTRACT FROM AUTHOR]

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Reliable estimation of seismic stability of structures built in seismically active regions is an objective that requires a complex investigation and different types of activities. For historical structures and monuments, this requirement is even more essential, because many of them represent unique heritage structures. In-situ testing of a monument for defining dynamic characteristics and seismic testing of scaled models represent the recommended activities to be considered as mandatory. Shake table testing of a scaled monument model provides valuable information about its seismic stability – weak parts and development of failure mechanism – as well as the crucial points of the structure that should be considered when designing the health monitoring system. This paper presents the results obtained by the shake table testing of scaled models of two historical masonry structures: the Old Bridge in Mostar and the ancient Protiron structure in Split. The monitored seismic response presented herein by the measured accelerations, relative and absolute displacements, and strains, as well as the damage identification during the shake table tests, provided essential information about their seismic stability, failure mechanism, and weak points. The obtained results have been used for verification of the analytical models for these two monuments, while the prospective of the conclusions derived from the tests has a possible implementation in planning their health monitoring system. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the seismic behavior of enclosed seawater walls, the buried site of which lies in liquefaction soil. An experimental specimen was manufactured and tested on the seismic table, and a numerical study was also modeled in the ABAQUS software based on the experimental outcomes. In both the experimental and numerical studies, a susceptible liquefaction layer around the root of the wall was considered due to the root lean soil leakage and large lateral pressure, and the soil behind the root caused the failure of the buried section. According to the results, the lateral movement significantly decreased due to the backing effect of this layer on the buried section of the wall. Furthermore, an active wedge was formed from the buried side to the back of the containment, and the braces were overwhelming due to the presence of the locks in the wedge and their movement along with the wedge. The displacement of the crown and foot of the wall decreased with the increased base acceleration and higher frequency of the entrance movement. [ABSTRACT FROM AUTHOR]

Summary: Balancing the workload of sophisticated simulations is inherently difficult, since we have to balance both computational workload and memory footprint over meshes that can change any time or yield unpredictable cost per mesh entity, while modern supercomputers and their interconnects start to exhibit fluctuating performance. We propose a novel lightweight balancing technique for MPI+X to accompany traditional, prediction‐based load balancing. It is a reactive diffusion approach that uses online measurements of MPI idle time to migrate tasks temporarily from overloaded to underemployed ranks. Tasks are deployed to ranks which otherwise would wait, processed with high priority, and made available to the overloaded ranks again. This migration is nonpersistent. Our approach hijacks idle time to do meaningful work and is totally nonblocking, asynchronous and distributed without a global data view. Tests with a seismic simulation code developed in the ExaHyPE engine uncover the method's potential. We found speed‐ups of up to 2‐3 for ill‐balanced scenarios without logical modifications of the code base and show that the strategy is capable to react quickly to temporarily changing workload or node performance. [ABSTRACT FROM AUTHOR]

In order to better evaluate the lifetime performance of glass panel facade systems, this study firstly proposes to conduct a full-scale wind resistance, air/water infiltration, and seismic resistance tests. Two specimens were designed, constructed, and tested for this purpose. A fatigue process is also applied to one of the manufactured systems in addition to a standard test procedure. Secondly, data acquired from the experimental part of this work have been used in a multi-criteria performance evaluation process to determine the performance levels of each of the specimens. In the evaluation process, a total of 10 different criteria and 2 alternatives are identified for decision making. Performance indicator data obtained from the detailed calculations using the AHP (Analytic Hierarchy Process), COPRAS (Complex Proportional Assessment) and TOPSIS (The Technique for Order of Preference by Similarity to Ideal Solution) methods are then utilized during the numerical assessment process. The 'criticality level' is defined within the evaluation process and it indicates the percent (%) values of the obtained performance indicators. As a result of the performance evaluations, the AHP and TOPSIS methods gave similar results and could be selected as the preferred methods for the evaluation of such experimental data. Results obtained from the AHP and TOPSIS methods are consistent and easy to interpret when compared to the COPRAS method. Furthermore, in this work, the most critical criterion is found to be the frontal deflections. [ABSTRACT FROM AUTHOR]

Multi-degree-of-freedom multiple table systems are developed for seismic testing of large-span structures to spread the loads evenly on the tables. Synchronous control of multiple shaking tables is challenging because of coupling between different shaking tables and complex dynamics of the testing systems. This article presents an adaptive waveform control for a two-degree-of-freedom dual electrohydraulic shaking tables testing system to improve the acceleration tracking performance. Synchronous control of the two electrohydraulic shaking tables is transformed into the motion control of a two-degree-of-freedom over constrained shaking table driven by 10 actuators. The force control loop based on the null space of the Jacobian matrix is developed to reduce the cross-coupling among the actuators. An adaptive acceleration waveform control method based on the DFP optimization algorithm in a complex domain is presented to improve the convergence and stability of the compensation algorithm in the outer control loop and replicate the acceleration reference waveforms accurately. Experimental results obtained in step responses, acceleration frequency responses measurement, and two- degree-of-freedom waveform replication tests are used to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Parallel Seismic (PS) method is a straightforward Nondestructive Testing (NDT) method capable of providing valuable information of unknown bridge foundations made of various common construction materials such as wood, steel, and reinforced concrete. Although numerous investigations on various aspects of the method have been previously carried out, factors affecting the success of PS tests on steel H-piles still need to be investigated in more details. In the current study, PS tests were performed on steel H-piles of a highway bridge to study the selected factors affecting the signals obtained from sensors. It was revealed that factors such as striking method, presence of background noise, layered soils, and the distance between the borehole and the piles can affect the PS test data in steel H-piles. The findings of this study can help engineers in performing field tests as well as interpreting the results. The results of this experimental study could also validate a part of the conclusions of a recent theoretical study on the performance of PS tests in layered soils. [ABSTRACT FROM AUTHOR]

Copyright of Mauerwerk is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Full-waveform inversion (FWI) is a powerful technique to obtain high-resolution subsurface models, from seismic data. However, FWI is an ill-posed problem, which means that the solution is not unique, and therefore the expert use of the information is required to mitigate the FWI ill-posedness, especially when wide-aperture seismic acquisitions are considered. In this way, we investigate the multiscale frequency-domain FWI by using a weighting operator according to the distances between each source-receiver pair. In this work, we propose a weighting operator that acts on the data misfit as preconditioning of the objective function that depends on the source-receiver distance (offset) and the frequency used during the inversion. The proposed operator emphasizes information from long offsets, especially at low frequencies, and as a consequence improves the update of deep geological structures. To demonstrate the effectiveness of our proposal, we perform numerical simulations on 2D acoustic Marmousi2 case study, which is widely used in seismic imaging tests, considering three different scenarios. In the first two ones, we have used an acquisition geometry with a maximum offset of 4 and 8 km, respectively. In the last one, we have considered all-offsets. The results show that our proposal outperforms similar strategies, for all scenarios, providing more reliable quantitative subsurface models. In fact, our inversion result has the lowest error and the highest similarity to the true model than similar approaches. [ABSTRACT FROM AUTHOR]

Summary: The advanced gas‐cooled reactors (AGRs) are the backbone of the United Kingdom's nuclear generation fleet, producing approximately 17% of the country's electricity. Their safety cases are supported by thorough inspection and monitoring of their graphite cores and extensive theoretical, analytical, and experimental studies. This paper presents a unique, highly innovative and technically challenging earthquake engineering project that has provided vital evidence to underpin the seismic safety assessments of the AGRs. Two modelling approaches, one experimental (a multilayer array physical model), and one numerical (a SOLFEC nonsmooth contact dynamics computational model) have been developed to investigate the seismic behaviour of an aged graphite core. The synergetic relationship between the two approaches is a product of insightful collaborative learning between the University of Bristol and Atkins, with the experiments providing material parameters and validation data and the computer simulations feeding array design and test schedule recommendations to the physical model. The predictive capabilities of the physical and the numerical models are tested by direct comparison and the good agreement between the results has increased the confidence in both. The model's versatility allows a variety of core scenarios to be tested that can explore in detail the AGR core behaviour in seismic conditions. [ABSTRACT FROM AUTHOR]

Summary: This paper presents an experimental study on the performance of a shear‐sliding stud‐type damper composed of multiple friction units with high‐tension bolts and disc springs. A numerical evaluation of the response reduction effects achieved by the stud‐type damper is also presented. In dynamic loading tests, the behavior of stud‐type multiunit friction damper specimens was investigated. Three different full‐scale damper specimens, which were composed of five, six, or seven friction units with two or four sliding surfaces, were incorporated into loading devices for testing. The stud‐type friction dampers demonstrated stable rigid‐plastic hysteresis loops without any remarkable decrease in the sliding force even when subjected to repetitive loading, in addition to showing no unstable behavior such as lateral buckling. The damper produced a total sliding force approximately proportional to the number of sliding surfaces and friction units. The total sliding force of the stud‐type damper can thus be estimated by summing the contributions of each friction unit. In an earthquake response simulation, the control effects achieved by stud‐type dampers incorporated into an analytical high‐rise building model under various input waves, including long‐period, long‐duration and pulse‐like ground motions, were evaluated. A satisfactory response reduction was obtained by installing the developed stud‐type dampers into the main frame without negatively impacting usability and convenience in terms of building planning. [ABSTRACT FROM AUTHOR]

To explore the dynamic characteristics and influencing factors of immersed tunnels under the action of earthquakes, 5 groups of shaking table model tests were carried out. Three different site conditions (unsaturated sand site, homogeneous saturated sand site, and nonuniform site), structural stiffness, and seismic wave input direction were considered. By comparing the above influencing factors, the seismic response law affecting the immersed tunnels was obtained. The test results show that, under the action of horizontal earthquakes, the liquefaction of sand and the larger tunnel stiffness may influence the acceleration development of the soil layers; seismic wave input directions affect the excellent frequency and frequency range of the soil layers, and the liquefaction of sand and large structural stiffness change the shape of the Fourier spectrum curve of the soil layers; site conditions, structural stiffness, and seismic wave input direction have a significant effect on the internal forces of tunnels. Normally, the strain in the heterogeneous soil layer under the horizontal seismic wave input is the largest, and the peak strain of the upper side of the tunnel side wall and center column is larger than the lower part, while the mechanism of structural damage caused by vertical earthquakes is different. [ABSTRACT FROM AUTHOR]

Past lateral cyclic or seismic tests of concrete frames with smooth bars in columns are very few and limited as far as the test structure's size and geometry are concerned; moreover, they have not focused on the effect of detailing and lap-splicing of such bars on local and global behaviour. To help fill this knowledge gap with new data, the paper presents the cyclic lateral load test of a 2:3-scale three-storey, one-by-two-bay, strong beam-weak column RC frame, focusing on the effects of the column's smooth bars and of their detailing on local and global behaviour. Slippage of bars caused concentration of column deformations in flexural cracks at the top and base sections and gave to the global hysteresis loops a shape typical of bond-slip behaviour, but without cyclic strength decay. Despite chord rotation demands of up to 0.055 rads and storey drifts of almost 5%, damage was limited and had nothing to do with the use of smooth bars in the columns. Despite the important role of bar slippage for the response, bar strains show that wherever the surrounding concrete was in compression, column bars were in compression as well. Lap splices at and/or FRP wrapping of column end regions did not have systematic effects on column behaviour. Overall, no adverse effect of the use of smooth bars was identified. [ABSTRACT FROM AUTHOR]

The sliding hydromagnetic bearing is a low-friction isolator proposed in recent years. Its novelty lies in adaptive energy dissipation and alterable deflection constraint, which has been demonstrated by previous studies through pseudo-static tests and numerical simulations. In order to experimentally explore the effectiveness of the isolator for seismic mitigation of the base-isolated structure, a complete laboratory investigation by shaking table tests is carried out. Two sets of recorded three-dimensional and artificial one-dimensional horizontal earthquake ground accelerations pertaining to hard and soft soil sites are employed as the input to the table. The tests aim to explore the seismic mitigation of the base-isolated structure in terms of floor accelerations, interstory drifts, and horizontal torsions, as well as the seismic performance of the sliding hydromagnetic bearing in regard to oil leak prevention, deflection-resistance performance, and frictional behavior. The tests reveal that when subjected to far-field earthquake ground motions, the base-isolated structure with sliding hydromagnetic bearings exhibits a reasonable seismic mitigation of the floor accelerations and interstory drifts. In addition, it exhibits a satisfactory seismic mitigation of the horizontal torsions when subjected to either far-field or near-fault earthquake ground motions. It is also found that the workability of the sliding hydromagnetic bearing remains almost the same under different intensities of the considered earthquake ground motions. Furthermore, it is seen that the sliding hydromagnetic bearings exhibit a good oil leak prevention and deflection-resistance performance. The determined relationship between kinetic friction coefficient, bearing velocity, and axial compression in these tests reveals a similar finding in the previous pseudo-static test in that the sliding hydromagnetic bearing exhibits a shear thinning that becomes more remarkable under a larger axial compression and a higher sliding velocity. [ABSTRACT FROM AUTHOR]

The first application of GaoFen-3 synthetic aperture radar (SAR) interferometry to monitoring co-seismic deformation of an earthquake is presented in this paper. First, two GaoFen-3 SAR images spanning the 2017 surface-wave magnitude ( M s ) 7.0 Jiuzhaigou earthquake were mosaicked, coregistered and processed into an interferogram with visible fringes. After the removal of severe orbital errors and unwrapping, the co-seismic deformation field is obtained. Finally, the fault parameters and slip distribution are determined based on the deformation field. To evaluate the performance of GaoFen-3 in this case, the interferogram, co-seismic deformation field, derived fault parameters and slip distribution are compared with those derived from Radarsat-2, Sentinel-1A and Advanced Land Observing Satellite-2 (ALOS-2) Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2). The comparisons between the deformation field obtained from GaoFen-3 and those obtained from Radarsat-2 and Sentinel-1A show Pearson's correlation coefficient ( r) values > 90%, demonstrating that GaoFen-3 interferometry can measure the co-seismic deformation effectively. The resultant slip model obtained by GaoFen-3 interferometric measurements shows a simple, elliptical pattern of slip, reaching a maximum of approximately 1 m at depths of 10–13 km. The rake angle is almost 0 ∘ , which suggests left-lateral strike-slip motion, consistent with previous studies. [ABSTRACT FROM AUTHOR]

Momentary discomfort caused by high-speed trains passing through complex terrain sections under strong wind conditions has become an urgent engineering problem in China. However, few scholars or research institutions have focused on this topic, and there are no standards for the evaluation of such discomfort. Therefore, in this study, the suitability of existing vibration comfort-evaluation methods under strong wind conditions was investigated by a full-scale test, and the characteristics of the car-body vibration and momentary discomfort under strong wind conditions were analyzed. It was indicated that low-frequency transient roll motion and transverse motion of the car-body are the main causes of discomfort, and the comfort-assessment methods in European standard (EN-12299) could not be directly used under these conditions. Consequently, an evaluation method for momentary discomfort caused by high-speed trains passing through complex terrain sections under strong wind conditions is suggested. [ABSTRACT FROM AUTHOR]

Summary: In regions of low to moderate seismicity in North America, reinforced masonry structures are mostly partially grouted. The behavior of such structures under lateral seismic loads is complicated because of the interaction of the grouted and ungrouted masonry. As revealed in past experimental studies, the performance of partially grouted masonry (PGM) walls under in‐plane cyclic lateral loading is inferior to that of fully grouted walls. However, the dynamic behavior of a PGM wall system under severe seismic loads is not well understood. In this study, a full‐scale, one‐story, PGM building designed for a moderate seismic zone according to current code provisions was tested on a shake table. It was shown that the structure was able to develop an adequate base shear capacity and withstand two earthquake motions that had an effective intensity of two times the maximum considered earthquake with only moderate cracking in mortar joints. However, the structure eventually failed in a brittle manner in a subsequent motion that had a slightly lower effective intensity. A detailed finite element model of the test structure has been developed and validated. The model has been used to understand the distribution of the lateral force resistance among the wall components and to evaluate the shear‐strength equation given in the design code. The code equation has been found to be adequate for this structure. Furthermore, a parametric study conducted with the finite element model has shown that the introduction of a continuous bond beam right below a window opening is highly beneficial. [ABSTRACT FROM AUTHOR]

Based on the similarity theory, a large-scale shaking table test of a shallow double-arch tunnel under unsymmetrical pressure with a similarity ratio of 1 : 20 was designed and completed, and a foam concrete damping layer was set in the double-arch tunnel. The acceleration response, strain response, and crack distribution of double-arch tunnels under different intensities and different directions of the Wenchuan wave excitation were studied (WC-X, WC-Z, and WC-XZ). The results showed that (1) the bias side (right hole) is greatly affected by the unevenness of the cover soil, and the horizontal acceleration response difference between the two tunnels is large and there is no symmetry. The incident direction of seismic waves has a great influence on the acceleration response of double-arch tunnels. The amplification factor of WC-Z is greater than that of WC-X. (2) On the same horizontal plane, with the vertical centerline of the middle wall as the axis of symmetry, the vertical acceleration amplification factor also has a large difference between the arch foot and the shoulder, but the difference is relatively small at other points. (3) The dynamic strain increases with the increase of seismic intensity, and the tendency is similar under the three different seismic wave excitation directions. The lining is under tensile strain and compressive strain, the strain of the left hole is greater than the strain of the right hole, and severe stress concentration occurs at the top left of the mid partition. (4) The middle partition, shoulder, and vault of the left hole and the shoulder, vault, and foot of the right hole are weak parts of earthquake resistance. Therefore, special attention should be paid to the seismic design. [ABSTRACT FROM AUTHOR]

The cross-sea bridges play an important role to promote the development of regional economy. These bridges located in earthquake-prone areas may be subjected to severe earthquakes during their lifetime. Group pile foundations have been widely used in cross-sea bridges due to their structural efficiency, ease of construction, and low cost. This paper investigates the seismic performance of bridge pile foundation based on the seismic fragility analysis. Based on the analysis platform OpenSees, the three-dimensional finite model of the bridge pile foundation is developed, where the pile-water interaction is replaced by the added mass method, nonlinear p-y, t-z, and q-z elements are used to simulate pile-soil interaction, and the displacement of the surface ground motion due to seismic excitations is applied on all spring supports. The seismic fragility curves of the bridge pile foundation are generated by using the earthquake records recommended by FEMA P695 as input motions. The curvature ductility based fragility curves are obtained using seismic responses for different peak ground accelerations. The effects of pile-water interaction, soil conditions, and different types of ground motions on the bridge pier fragilities are studied and discussed. Seismic fragility of the pier-group pile system shows that Sec C (the bottom section of the pier) is the most vulnerable section in the example fluid-structure-soil interaction (FSSI) system for all four damage LSs. The seismic responses of Sec E (a pile section located at the interface of the soil layer and water layer) are much lower than other sections. The parameter analysis shows that pile-water interaction has slight influence (less than 5%) on the fragility curves of the bridge pier. For the bridge group pile foundations considering the fluid-pile-soil interaction, PNF may induce larger seismic response than far-field (FF) and no-pulse near field (NNF). The bridge pile foundation in stiff soil is most vulnerable to seismic damage than soft condition. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The project design of the Subiyah link of the Sheikh Jaber Al-Ahmad Al-Sabah Causeway in Kuwait was implemented after lengthy discussions and research due to limits in the standards. With 36 km of viaducts in this link, all design decisions had a significant impact on quantities and hence on costs. The project is based on 2.5 and 3.0 m monopiles, but the requirements of the design standards are not fully adapted for such diameters. Moreover, some additional project requirements, which are not addressed in most of the codes, made the design more complex. All of these parameters led to difficulties in earthquake design regarding the R factor value, capacity design, seismic detailing, P-delta effect, asynchronous motion and seismic design of bearings. The aim of this article is to present all the difficulties in the design of atypical structures, the related discussions and research, and the numerous comparisons that have been made with Eurocode 8-2 to find a consistent design. [ABSTRACT FROM AUTHOR]

In this paper, the seismic behaviour of the floating piles row was installed into a loose dry sandy slope by help of 3D numerical simulations has been studied. A parametric 3D numerical modelling is conducted within the framework of the finite difference method. Both near-fault and far-field earthquakes have been applied to derive new relationships between shear forces generated in piles and depth along the piles under effects of the one, two and triaxial seismic loadings in the large-scale numerical models of sandy slope-floating piles row. As an innovation, the pattern and the amount of lateral displacements as well as the generated shear forces in the piles row are calculated under effects of the NF and FF records. In addition, the increase values of slope settlement have been investigated under two and triaxial seismic loadings compared to conventional uniaxial loading. The validation of the results obtained by numerical method was controlled using the investigation of the slope settlements reinforced by a piles row with the help of shaking table and a good agreement was observed between the numerical and experimental results. [ABSTRACT FROM AUTHOR]