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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.)

To investigate the impact of foundation settlement in loess areas on the dynamic response of liquid storage structure (LSS) under seismic motion, a finite element analysis model of the liquid–solid coupling of LSS was established using ADINA V9.6 software. By analyzing the dynamic response patterns of LSS under seismic motion with foundation failure, this study examines the effects of foundation failure and the direction of seismic wave incidence on the equivalent stress, maximum shear stress, wall displacement, and liquid sloshing wave height of the structure. The results indicate that among the three foundation failure scenarios, foundation failure at the center of the tank bottom has the least impact on the structural dynamic response. In contrast, foundation failure affecting one-fourth of the tank base has the greatest impact. Furthermore, compared to seismic motion along the X-axis, the dynamic response of the structure is more significantly affected when seismic motion co-occurs along the X-Z-axis. [ABSTRACT FROM AUTHOR]

To investigate the stability of jointed slopes under seismic action, a random joint fracture network model was established using the Monte Carlo method. The discrete element program 3DEC was utilized to conduct a numeri- cal simulation study on the stability of an open-pit mine slope under seismic action. The results indicate that under seismic action, the vibration intensity and displacement at the bottom of the slope are significantly stronger than those at the top. The joint fractures within the slope have a notable attenuating effect on the energy of seismic waves. The bottom of the slope primarily exhibits a shear failure mode, indicating the need to reinforce the seismic resistance of the slope's bottom structure during routine production. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China University of Technology (Natural Science Edition) is the property of South China University 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.)

In order to explore the failure mode of the cable-stayed pipe bridge under earthquake action, taking the structural system of an oil and gas pipeline–cable-stayed pipe bridge as the research object, the full-scale finite element calculation model of the cable-stayed pipe bridge–oil and gas pipeline structural system as well as the finite element calculation model considering the additional mass of the oil and gas medium and the fluid–structure interaction effect were established by using ANSYS Workbench finite element software. The stress and displacement of the cable under the earthquake action were analyzed in the time history, as were the response characteristics of the cable when subjected to both methods. The calculation results show that the overall failure of the pipeline is basically the same under the two methods. Compared with the additional mass method, the solution for the fluid–structure coupling method can be derived through a comprehensive analysis of the flow field and structure, respectively, avoiding the sudden change caused by model simplification or calculation error so that the analysis results can better simulate the actual situation. In summary, the fluid–structure interaction method enables a more precise prediction of the dynamic response of the structure, and the findings of this research can provide a theoretical foundation and technical guidance for optimizing the seismic performance of cable-stayed pipe bridges. [ABSTRACT FROM AUTHOR]

Copyright of Railway Construction Technology is the property of Railway Construction Technology Editorial Office 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.)

Copyright of Railway Investigation & Surveying is the property of Railway Investigation & Surveying Editorial Office 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.)

In this study, the influence of confined concrete models on the response of reinforced concrete structures is investigated at member and global system levels. The commonly encountered concrete models such as Modified Kent-Park, Saatçioğlu-Razvi, and Mander are considered. Two moment-resisting frames designed according to the pre-modern code are taken into consideration to reflect the example of an RC moment-resisting frame in the current building stock. The building is in an earthquake-prone zone located on Z3 Soil Type. The inelastic response of the building frame is modelled by considering the plastic hinges formed on each beam and column element for different concrete classes and stirrups spacings. The models are subjected to non-linear static analyses. The differences between confined concrete models are comparatively investigated at both reinforced concrete member and system levels. Based on the results of the comparative analysis, it is revealed that the column behaviour is mostly influenced by the choice of model, due to axial loads and confinement effects, while the beams are less affected, and also it is observed that the differences exhibited in the moment-curvature response of column cross-sections do not significantly affect the overall behaviour of the global system. This highlights the critical role of model selection relative to the concrete strength and stirrup spacing of the member. [ABSTRACT FROM AUTHOR]

In the present study, a series of shaking table model tests were performed on a slope with a gabion reinforced retaining wall. Transfer functions were employed to compute the inherent frequencies of the slope. Furthermore, the investigation examined various aspects of the slope, including the peak acceleration amplification factor, incremental dynamic stresses, displacements, and tensile forces. Additionally, the study employed the Hilbert Huang transform (HHT) to analyze the slope's time-frequency characteristics and energy distribution. The findings of the study revealed that there is an inverse relationship between the amplitude of the input seismic wave and the natural frequency of the top of the gabion reinforced retaining wall slope. As the amplitude of the seismic wave increases, the natural frequency of the slope decreases. The amplification factors for peak acceleration were all found to be less than 1.9, suggesting a notable dissipation of seismic energy in comparison to typical slopes. The response of incremental dynamic stress was most pronounced in the middle section of the slope, followed by the top of the slope. The magnitude of the incremental displacement was found to be highest at layer 4, whereas the incremental tensile force exhibited its maximum value at layer 5. The dynamic response exhibited the least pronounced characteristics at the lower portion of the slope, demonstrating the most stable behavior. The peak frequencies observed in the Hilbert marginal spectrum displayed comparable characteristics to the natural frequencies. • Large-scale shaking table tests were conducted on the stepped gabion reinforced retaining wall slope. • The natural frequency, damping ratio, and dynamic shear modulus were used to analyze the dynamic characteristics of the gabion reinforced retaining wall slope under seismic action. • The energy dissipation mechanism of the gabion reinforced retaining wall slope was investigated by peak acceleration amplification factor, dynamic stress increment, displacement increment and tension increment. • The time-frequency domain and energy perspective of the gabion reinforced retaining wall slope under seismic action was analyzed by using HHT, and the damage evolution mechanism inside the slope when the amplitude of input seismic wave increases is revealed. [ABSTRACT FROM AUTHOR]

The design of optimal seismic protection systems on bearings with hysteresis behavior leads to a conditional multidimensional global optimization problem with a nonlinear and non-differentiable objective function. In this paper, bearings with bilinear characteristic with hysteresis are considered, i.e. for each nonlinear bearing there are four parameters to optimize: ultimate elastic displacement and stiffness for the elastic mode and ultimate displacement and stiff-ness for the inelastic mode. We study the seismic response of an elastic beam on four nonlinear bearings under vertical seismic ground motion. The perturbation functional as an integral of the quadratic form of the state vector with a weight matrix formed from the stiffness and inertia matrices of the system on equivalent elastic supports is considered as the objective function. Minimization of the functional means the minimum of the total energy of the system on equivalent elastic bearings. Genetic algorithm is used to solve the optimization problem.

Abstract To explore the cumulative deformation effect of the dynamic response of a tunnel crossing the hauling sliding surface under earthquakes, the shaking table test was conducted in this study. Combined with the numerical calculations, this study proposed magnification of the Arias intensity (MIa) to characterize the overall local deformation damage of the tunnel lining in terms of the deformation characteristics, frequency domain, and energy. Using the time‐domain analysis method, the plastic effect coefficient (PEC) was proposed to characterize the degree of plastic deformation, and the applicability of the seismic cumulative failure effect (SCFE) was discussed. The results show that the low‐frequency component (f1 and f2 ≤ 10 Hz) and the high‐frequency component (f3 and f4 > 10 Hz) acceleration mainly cause global and local deformation of the tunnel lining. The local deformation caused by the high‐frequency wave has an important effect on the seismic damage of the lining. The physical meaning of PEC is more clearly defined than that of the residual strain, and the SCFE of the tunnel lining can also be defined. The SCFE of the tunnel lining includes the elastic deformation effect stage (

To investigate the impact of foundation settlement in loess areas on the dynamic response of liquid storage structure (LSS) under seismic motion, a finite element analysis model of the liquid–solid coupling of LSS was established using ADINA V9.6 software. By analyzing the dynamic response patterns of LSS under seismic motion with foundation failure, this study examines the effects of foundation failure and the direction of seismic wave incidence on the equivalent stress, maximum shear stress, wall displacement, and liquid sloshing wave height of the structure. The results indicate that among the three foundation failure scenarios, foundation failure at the center of the tank bottom has the least impact on the structural dynamic response. In contrast, foundation failure affecting one-fourth of the tank base has the greatest impact. Furthermore, compared to seismic motion along the X-axis, the dynamic response of the structure is more significantly affected when seismic motion co-occurs along the X-Z-axis.

Greenhouses have been widely used in facility agriculture at present. Gutter-connected greenhouses have been also extensively implemented to enhance the structural span for high land utilization with simplified mechanization. Among them, Venlo greenhouse has been the preferred choice among various forms of roof trusses, due to the simplified installation, superior light transmittance, and excellent sealing. The "National standard for the design of greenhouse structure " also released that "seismic action shall be calculated in the structural design of glass greenhouse for agricultural production in areas with seismic fortification intensity of 8 degrees (0.30g) and above". In this study, a regular-shaped Venlo-type greenhouse was designed to investigate the seismic performance and response using a shaking table test. A scaled-down model was then established with one span and two openings. The dynamic features of the modeled structure were analyzed to determine the acceleration response of the structure under the action of the 7-degree frequent, 7-degree fortification intensity, 7-degree rare, 8-degree rare, and 8-degree semi-rare earthquake. Numerical simulation was carried out in conjunction with finite element (FE) ANSYS software. The test and simulation were compared to verify the reliability of dynamic time-range analysis. In addition, the numerical model was established, according to the structural design of a Venlo greenhouse project. The time-history analysis was carried out under the action of 8 degrees and half rare earthquakes (the maximum acceleration time history was 0.51g). Meanwhile, the combination of permanent, snow, and crop load was selected, according to the specification. Three groups of seismic waves (namely AKT, NGA, and artificial wave) were input into the structure of the greenhouse. The mode of structure was analyzed to determine the internal force, vibration pattern and displacement with/without the action of the seismic waves. The results show that the maximum stresses in the overall structure of the greenhouse under seismic action were 1.24-2.12 times higher than those under no seismic action. The structural stresses during the action of artificial waves exceeded the yield strength of the material. Two cases (b1 and b2) were applied under the action of the same set of seismic waves. The b1 case was adopted to combine the live load with crop and snow loads, whereas, the b2 case combined the crop load only. There were similar values in the column top displacements. The seismic action dominated the column top displacements in these cases. The maximum displacements occurred in the outside wall storm columns. The largest displacement response was observed at the top of the structural columns under the action of artificial waves. The maximum of up to 72.17 mm exceeded the standard requirement of 1/250 of the elastic inter-story displacement angle for the seismic design of Chinese buildings. The research results can provide a theoretical reference for the safe design of Venlo greenhouse under seismic action. [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.)

To study the dynamic damage effect of lining across the main-sliding surface reinforced with multi-anchor round piles under different seismic sequences, two loading sequences of "foreshock-mainshock" and "mainshock-aftershock" were designed by shaking table test for the first time. Based on acceleration, the seismic performance evaluation factor (SPEC) and seismic effect coefficient (Sec) of reinforced lining were proposed. A calculation method for shear force (Sf) and bending moment (Mb) of multi-anchor round piles based on dynamic strain was proposed, and its distribution characteristics were given. The evaluation index of the reinforcement effect evaluation coefficient (REEC) of reinforced lining was put forward. The results showed that the acceleration of the main-aftershock sequence on multi-anchor round piles was greater than that of the foreshock-mainshock sequence. The Sf of pile presented an inverted "S" type distribution, while Mb exhibited an "S" type distribution. Compared with the unoptimized multi-anchor round piles, the seismic effect of Sec and REEC reached 3.04–18.96% and 120–180%, respectively. The seismic effect of anchor head optimization is related to the seismic sequence, which is more suitable for the seismic structure design of the foreshock-mainshock sequence, indicating its superior popularization value in tunnel-landslide engineering treatment in high-intensity areas. [ABSTRACT FROM AUTHOR]

In the territory of Herzegovina there is a large number of masonry buildings, the age of which exceeds 50 years. These are mostly smaller buildings, with one to two floors, while the load-bearing walls are mainly made of cut stone in lime mortar. Larger buildings with load-bearing walls made of bricks and concrete blocks in cement-lime mortar appeared a little later. The floor structures mainly consist of timber oak beams, supported by load-bearing walls, with boarding on the upper side and plaster, on reed netting, on the lower side. Such structures are exceptionally sensitive to seismic action, and almost certainly could not withstand the design seismic load without significant damage and collapse. A nonlinear static analysis of the structure of one such building was performed in this paper. A check of the existing condition was performed in the first analysis, and a check of the partially strengthened structure in the second. It is evident from the analysis that such strengthening significantly improves the bearing capacity, while the increase in deformability (ductility) is significantly smaller due to the very high stiffness of such structures.

In order to explore the failure mode of the cable-stayed pipe bridge under earthquake action, taking the structural system of an oil and gas pipeline–cable-stayed pipe bridge as the research object, the full-scale finite element calculation model of the cable-stayed pipe bridge–oil and gas pipeline structural system as well as the finite element calculation model considering the additional mass of the oil and gas medium and the fluid–structure interaction effect were established by using ANSYS Workbench finite element software. The stress and displacement of the cable under the earthquake action were analyzed in the time history, as were the response characteristics of the cable when subjected to both methods. The calculation results show that the overall failure of the pipeline is basically the same under the two methods. Compared with the additional mass method, the solution for the fluid–structure coupling method can be derived through a comprehensive analysis of the flow field and structure, respectively, avoiding the sudden change caused by model simplification or calculation error so that the analysis results can better simulate the actual situation. In summary, the fluid–structure interaction method enables a more precise prediction of the dynamic response of the structure, and the findings of this research can provide a theoretical foundation and technical guidance for optimizing the seismic performance of cable-stayed pipe bridges.

The resonance induced by an earthquake often causes more serious damage to the slope and directly affects its seismic performance. To study the resonance characteristics of a staggered rock slope, a 3D numerical model of the slope is established by using the finite element software ANSYS, and the effect of staggered space on the natural frequency of the slope is analyzed. The resonance response laws of different locations on the slope surface and the effect of the earthquake frequency on the stress of the slope are discussed by the harmonic response analysis. The results show that (1) the larger the slope slip distance is, the smaller the fundamental frequency is, and the resonance phenomena may occur under different staggered distances. The horizontal resonance displacement of the slope surface is larger than the vertical one. The front slope has a larger peak displacement and lower resonant frequency compared with those of the back slope. (2) Both the low and high-order natural frequencies can be excited to cause resonance, but the displacement of the high-order resonance is relatively small. The horizontal displacement peak of the front slope and back slope is in the order: top > middle > foot, while that of the side slope is in the order: middle > top > foot. Under high-frequency loading, the dynamic response of the slope at the lower part may be greater than that at the upper part. (3) The shear failure of the slope toe is the main damage in slope resonance. The location of the maximum shear and tensile stress is related to the range of loading frequency. The front slope is more prone to damage. Ground motions with low frequency have a greater influence on the front slope, while high frequency ground motions have the opposite effect. The results can be used as reference to determine the key reinforcement position of a staggered slope in the seismic fortification.

This paper is intended to examine the efficiency of utilizing the FRP composite material with an externally bonded technique in enhancing the behavior of the damaged B-C joints and controlling their failure mode using the NLFEA approach. At first, the modeled Beam-Column joint was validated as per the previously-attained experimentally-attained results. Later, the model was widened to experiment with the impact of axial-column load and the concrete compressive strength on the reinforced and un-reinforced models with FRP. To run the experiment, there were three cases of applying the axial column load: no load applied (0%), applying 25%, applying 50%, and applying 75%, while the concrete compressive strength degradation level was (0% damage), (25% damage), and (50% damage). All models were evaluated for structural performance, considering: the failure mode, stresses distribution, and the ultimate capacities in pulling and pushing with its corresponding displacements. However, the horizontal load-displacement hysteretic loops and envelopes, stiffness degradation, displacement ductility, and energy dissipation were reported. The experimental results revealed that using FRP to externally-reinforce B-C joints improved overall cyclic performance, as the FRP caused a rise in the ultimate load capacity, horizontal displacement, ductility of displacement, and displacement energy dissipation, while it slowed down the stiffness degradation. In addition, the FRP material converted the failure mode of the region between the joint and column from brittle to ductile due to the formation of a plastic hinge only on the side of the beam when the axial column load exceeded 25%. It must be noticed that when the column’s axial load is less than 25%, the ultimate capacity of axial load and resultant deflection is solely improved. However, it has been stated that increasing the column’s axial loading by 25% increases the resulting stiffness degradation by 3% for undamaged joints, which further increases by 16% for each increased damage level. In contrast, the absorbed energy is increased by 170% under axial loading, increasing by 25%, which is reduced to only one-fourth under the various damage levels. Generally, the resulting observations help specialized engineers retrofit appropriate B-C joints in already-standing buildings due to their accuracy.

Many regions in the world have experienced the presence of intensive geological events. Given this reality, the control of vibrations caused by earthquakes on buildings is one of the great challenges in seismic regions, as they can cause structural, material, and personal damage, and must be considered with special attention when carrying out a structural project. For this reason, it is necessary to minimize the deleterious effects caused by earthquakes on buildings. In this sense, the present study seeks to evaluate, through the theory of mechanical vibrations, the use of springs of variable stiffness in the control of accelerations induced by seismic action, because springs introduce restoring forces in the system. The evaluation is done through numerical-computational simulation using the finite element method. The frame structure of an idealized building is used in the modelling, where columns and beams are represented by linear elements and the floors by shell elements. In the simulation, springs of variable stiffness are inserted into the joints to control the vibrations produced by earthquakes. These devices are added to the structural system at different heights and directions, aiming to keep the structure's behaviour unchanged, neutralizing the effects of the earthquake. Based on the obtained results, it is possible to verify the required stiffness and the position in which the springs must be inserted to obtain the constancy of the structural frequency of vibration during the earthquake action.

In the territory of Herzegovina there is a large number of masonry buildings, the age of which exceeds 50 years. These are mostly smaller buildings, with one to two floors, while the load-bearing walls are mainly made of cut stone in lime mortar. Larger buildings with load-bearing walls made of bricks and concrete blocks in cement-lime mortar appeared a little later. The floor structures mainly consist of timber oak beams, supported by loadbearing walls, with boarding on the upper side and plaster, on reed netting, on the lower side. Such structures are exceptionally sensitive to seismic action, and almost certainly could not withstand the design seismic load without significant damage and collapse. A nonlinear static analysis of the structure of one such building was performed in this paper. A check of the existing condition was performed in the first analysis, and a check of the partially strengthened structure in the second. It is evident from the analysis that such strengthening significantly improves the bearing capacity, while the increase in deformability (ductility) is significantly smaller due to the very high stiffness of such structures. [ABSTRACT FROM AUTHOR]

Copyright of Rudarsko-Geolosko-Naftni Zbornik is the property of Faculty of Mining, Geology & Petroleum Engineering 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.)

Copyright of China Sciencepaper is the property of China Sciencepaper 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.)

Cracks broadly exist within slopes due to desiccation, weathering, or wetting–drying cycles in Nature. The presence of cracks inevitably reduces slope stability. However, such fissured slopes have received little attention, especially when subject to earthquake action, which is considered one of the most significant inducements of slope instability. In practice, antislide piles have proven useful measures to stabilize slopes, while the performance of antislide piles in fissured slopes subjected to seismic action is inexplicit. To this end, this study aims to develop an effective method to assess the seismic stability of three-dimensional (3D) fissured slopes reinforced with piles. The modified pseudodynamic approach is introduced to properly present the dynamic characteristic of seismic waves in real cases. Based on the kinematic approach of limit analysis, a 3D failure mechanism integrating cracks and antislide piles is developed to describe the slope failure. Open cracks (cracks existing before slope failure) and formation cracks (cracks forming as part of the failure mechanism) are both considered. The effect of seismic action is expressed by incorporating the work rates of seismic force. Thanks to the principle of work–energy balance, solutions of safety factors can be obtained by the application of an optimization scheme. The proposed method is verified through a detailed comparison with previous investigations. This paper ends with a description of a parametric study to reveal the effects of cracks, pseudodynamic seismic action, and the design of antislide piles on slope stability. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office 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.)

This paper is intended to examine the efficiency of utilizing the FRP composite material with an externally bonded technique in enhancing the behavior of the damaged B-C joints and controlling their failure mode using the NLFEA approach. At first, the modeled Beam-Column joint was validated as per the previously-attained experimentally-attained results. Later, the model was widened to experiment with the impact of axial-column load and the concrete compressive strength on the reinforced and un-reinforced models with FRP. To run the experiment, there were three cases of applying the axial column load: no load applied (0%), applying 25%, applying 50%, and applying 75%, while the concrete compressive strength degradation level was (0% damage), (25% damage), and (50% damage). All models were evaluated for structural performance, considering: the failure mode, stresses distribution, and the ultimate capacities in pulling and pushing with its corresponding displacements. However, the horizontal load-displacement hysteretic loops and envelopes, stiffness degradation, displacement ductility, and energy dissipation were reported. The experimental results revealed that using FRP to externally-reinforce B-C joints improved overall cyclic performance, as the FRP caused a rise in the ultimate load capacity, horizontal displacement, ductility of displacement, and displacement energy dissipation, while it slowed down the stiffness degradation. In addition, the FRP material converted the failure mode of the region between the joint and column from brittle to ductile due to the formation of a plastic hinge only on the side of the beam when the axial column load exceeded 25%. It must be noticed that when the column's axial load is less than 25%, the ultimate capacity of axial load and resultant deflection is solely improved. However, it has been stated that increasing the column's axial loading by 25% increases the resulting stiffness degradation by 3% for undamaged joints, which further increases by 16% for each increased damage level. In contrast, the absorbed energy is increased by 170% under axial loading, increasing by 25%, which is reduced to only one-fourth under the various damage levels. Generally, the resulting observations help specialized engineers retrofit appropriate B-C joints in already-standing buildings due to their accuracy. [ABSTRACT FROM AUTHOR]

The dynamic characteristics and liquid sloshing of a circular tank are analysed using ADINA software through seismic response analyses. The maximum sloshing wave height for the circular tank under unidirectional horizontal seismic action is developed. The calculation method involves three parameters such as tank radius, seismic coefficient and dynamic coefficient. The dynamic coefficient of liquid sloshing is determined corresponding to the long-period seismic design β spectrum with a 5% damping ratio using basic sloshing period. The established method can guide the seismic design of liquid-containing structures. The established method of calculating sloshing wave height is compared with those in the American code.

• The evaluation method of model boundary effect and dynamic characteristics of shaking system is put forward. • A method for evaluating the failure mode of model soil based on MSE is proposed. • A damage evaluation method of EMD energy damage index for lining is proposed. This paper presents the findings of a series of shaking table tests conducted to investigate the seismic damage and dynamic characteristics of a tunnel crossing a sliding surface system. An evaluation methodology is introduced to assess the model's boundary effects and dynamic characteristics. In this study, we propose a model soil failure mode assessment method based on Marginal Spectral Entropy (MSE) using Hilbert-Huang Transform (HHT) and information entropy parameters. Furthermore, a damage evaluation method for tunnel lining is presented, which utilizes the Hilbert Energy Spectrum (HES) and an Empirical Mode Decomposition (EMD) energy damage index. The results of the tests reveal that the MSE accurately reflects the slope failure process and provides insights into the depth of the sliding surface. The observed behavior of the model indicates a push-back shear slip type characterized by sinking, squeezing, pulling, and shearing. The HES analysis of the model soil indicates that the energy primarily concentrates in the frequency range of 0 to 25 Hz, expanding with elevation. Notably, the tunnel crossing the hauling sliding surface exhibits a more pronounced broadband effect in the model soil compared to the main sliding surface. The peak HES of the lining occurs after that of the model soil and is found to be 18.07 s. The damage index distribution correlates with the spatial position of the lining parts. When the damage index exceeds 90 %, it indicates the presence of significant damage to the specific parts of the lining, a finding that has been validated through post-seismic analysis. Furthermore, the EMD energy damage index, in conjunction with dynamic finite element simulation, demonstrates its potential for preliminarily determining the location and extent of lining damage through abrupt changes. The research findings contribute to the theoretical understanding of extracting damage features in tunnel-landslide models. [ABSTRACT FROM AUTHOR]

Earthquakes and extreme waves pose significant threats to the safety of offshore bridges, particularly in deep-water environments. The temporal sequence of earthquakes and waves and the specific type of earthquake are critical factors that contribute to the potential risks involved. This study aimed to fill a key knowledge gap by conducting a comprehensive series of physical tests on a deep-water bridge pier at a scale factor of 1:30. White noise tests, shaking table tests, wavemaker tests, and combined shaking table and wavemaker tests were carried out. Near-field pulsed earthquakes, far-field long-period earthquakes and earthquake-wave phase differences were examined in the tests. The test results indicate that the presence of water has a noticeable impact on the natural frequency, particularly the 2nd-order frequency, of bridge piers, which may significantly influence the dynamic responses of high bridge piers. The effects of water–pier interactions are further intensified by seismic actions such as the pulsed Loma Prieta and long-period Chi-Chi earthquakes. Moreover, the earthquake-induced hydrodynamic pressures on the upstream and downstream faces of the pier are nearly identical, whereas there is a notable difference when the pressures are caused by incident waves. The magnitude of the combined earthquake and wave responses in relation to the individual responses is influenced by the earthquake–wave phase differences, and the combined responses are less than the sum of the individual responses. • Dynamic responses of bridge piers to earthquakes and waves are investigated and carried out through joint tests. • Phase differences between earthquakes and waves are emphasized, and pulsed and long-period earthquakes are considered. • The effect of combined action on bridge pier responses and the distribution of hydrodynamic pressures are summarized. [ABSTRACT FROM AUTHOR]

The reliability analysis is one of the main methods for the quantitative analysis of the safety in the geotechnical engineering. This method can provide the failure probability with a clear physical meaning. Due to the complex structure of high earth-rock dams and the non-linear characteristics of the material properties, it is very difficult to perform the reliability analysis on such large nonlinear structures. Currently, there are few studies on the reliability analysis of high earth-rock dams that consider the earthquakes, the dam body deformation and the dam slope stability at the same time. In this paper, the dam cracks generated by the earthquakes are used as the criteria for the dam body seismic deformation evaluation, and the inclination method is adopted for the dam body seismic deformation analysis. The simplified Bishop method combined with the ratio of the safety margin method is used to analyze the dam slope stability. In order to consider the soil material properties, the thickness of the compressible soil layer and the uncertainty of the earthquakes, a seismic failure probability analysis method for evaluating the seismic danger of high earth-rock dams considering the dam body deformation and the dam slope stability is established based on the reliability theory. Taking a concrete face rockfill dam as an example, the method is used to analyze the seismic failure probability of the dam during the design reference period. It provides the reference for the seismic design and the risk analysis, and establishes the risk level of high earth-rock dams. [ABSTRACT FROM AUTHOR]

For the seismic safety of tunnels with cavity behind lining, based on the finite element method, the viscoelastic artificial boundaries are introduced to study the influence of the location of cavity behind lining on the seismic response of tunnel structure under vertically incident SV wave. The analysis results show that the cavity behind the lining has a significant effect on the seismic response of tunnel structure, and the appearance of cavity behind lining will significantly change the dynamic characteristics of tunnel structure; when the incidence frequency of wave is close to the natural vibration frequency of tunnel structure, the lining stress has the largest amplification when the cavity appears behind the vault; Regardless of the cavity location, the maximum of lining stresses always appears at the arched foot, and the vault stress has the largest amplification; Under the Taft wave, the maximum stress 1.642 MPa of lining without cavity appears at the arched foot, and the minimum 0.118MPa at the arched waist, the stress amplification at the vault can reach about 760 %, which is unfavorable to tunnels. In addition, the soil property also has a great influence on the tunnel; the layered site will lead to the obvious change of the seismic wave, hence the geological data should be collected in detail in the seismic design of tunnel. Meanwhile it is proposed that the PE material can be filled back into the cavities behind the tunnel lining to reduce the earthquake damage of tunnels. [ABSTRACT FROM AUTHOR]

In recent years, earthquake disasters have seriously damaged nonstructural components, so it is necessary to study their seismic performance. However, the existing scholarly research mainly concentrates on multistorey and high-rise buildings, and there are still deficiencies in the analysis of the seismic performance of the nonstructural components in large-span structures under seismic action. In this paper, the acceleration responses of a single-layer spherical reticulated shell structure are compared with those described in the current seismic design codes of the nonstructural components, and it is found that the current codes are not fully applicable to the seismic design of the nonstructural components in reticulated shell structures. The calculation formulas of the acceleration response spectra of single-layer spherical shell nodes are theoretically derived, and the shell node acceleration response spectra are affected by higher-order modes, orthogonal horizontal seismic input directions, and the membrane stiffness of the shell nodes. The variations in the acceleration responses of the shell nodes with node position and rise-to-span ratio are analysed, and a design method for the equivalent seismic action of the nonstructural components in a single-layer spherical reticulated shell with a roofing system is proposed. [ABSTRACT FROM AUTHOR]

This paper is a continuation of the research on reinforcement of masonry walls using a combination of metal frames and mechanical dampers. This paper analyzes a single metal frame with and without reinforcement with mechanical dampers in order to have a clearer insight into the behavior of individual reinforcement components. It presents an overview of the basic characteristics of mechanical dampers, their configuration and combinations with metal frame, and special emphasis is placed on their earthquake behavior. The results of the numerical analysis for a single metal frame were obtained using two modern software packages, ABAQUS and SAP2000. After the results of the individual metal frame were obtained, the metal frame was strengthened by applying mechanical dampers and analyzed.

A technique that allows reliably modelling the non-reflecting properties of the boundaries of a finite element model is considered. The indicated technique has been tested on the example of a large arched-gravity concrete hydroelectric power plant. At that, the experience of VNIIG experts was used in modelling non-reflecting boundaries, determining the dynamic loads and dynamic properties, such as damping, and elastic properties of the soil-structure system. In addition, advanced techniques for modelling non-reflecting boundaries were tested and the results were compared with the techniques previously implemented at VNIIG. [ABSTRACT FROM AUTHOR]

This paper presents the results of an experimental study on the behavior of the cold- formed steel shear wall panel (CFSSWP) with fibrocement panels as sheathing, when it is subjected in-plane shear deformations and flexural deformation under perpendicular monotonically increasing horizontal loads on the longest plane. A full-scale housing section was built with three walls and a ceiling using commonly used construction details in El Salvador. The strength and stiffness of the experimental specimen tested overcame significantly critical demand imposed by the technical design standards in this country. Additionally, a simplified finite element model was defined with the objective to analyze stresses in the components. The results of the numerical model were similar to the experimental model tested. [ABSTRACT FROM AUTHOR]

After the promulgation and implementation of the fifth-generation Seismic Ground Motion Parameters Zonation Map of China, seismic fortification requirements are up comprehensively. Seismic assessment, as well as seismic reinforcement, has more and more complex challenges. By introducing performance-based seismic design principle, a performance-based seismic assessment method for existing buildings is proposed. The value of seismic action, seismic performance target, durability damage model and seismic analysis method in the evaluation method system are introduced. An example of frame structure teaching building reinforcement project can illustrate the feasibility of performance-based seismic assessment and reinforcement design. The research results show that the earthquake action should be adjusted according to the principle of equal exceedance probability for the existing buildings, and the seismic fortification targets of existing buildings are consistent with those of new buildings under the premise of the same probability guarantee. So the seismic performance targets of existing buildings can be determined by the relevant regulations of new buildings. At the same time, the durability damage of existing structures should be considered in the performance evaluation. The performance-based assessment and design method for seismic reinforcement of existing buildings can directly and quantitatively evaluate the performance of building structures under medium and large earthquakes, for more accurate judgement in existing buildings reinforcement. [ABSTRACT FROM AUTHOR]

In order to explore the stability characteristics of hydropower station slope under different working conditions under seismic action, the three-dimensional dynamic finite element method was used to analyze the working conditions of the hydropower station slope under the seismic load with a probability of exceeding 5% in 50 years, 2% in 100 years, and 1% in 100 years in the reference period, through comparing the dynamic response characteristics and the stability of the slope under different seismic load were obtained. The results showed that under the influence of different earthquake loads, the ground motion response of the slope would increase with the increase of the peak value of the excited ground motion, and all would be forced to vibrate according to the vibration form of the excited ground motion; compared with the amplification effect of the slope on the displacement, the amplification effect of the slope on the acceleration was more obvious, this phenomenon was more obvious when the slope was under the action of an earthquake load with a probability of exceeding 1% within 100 years of the reference period; with the increase of seismic load, the possibility of bedding sliding and failure of the slope surface would be greater; when the three types of seismic loads act on the slope respectively, the other surfaces of the slope would generate instantaneous tensile stress, but they were less than the tensile strength of the slope rock mass. When the slope was under rare ground motion with a 100-year exceeding probability of 1% and 2%, the maximum relative dynamic displacement was about 5 cm, and the slope was sufficient to withstand the test of strong ground motion; for the other two seismic conditions, when the slope was under the action of an earthquake load with a probability of exceeding 1% within 100 years of the reference period, the damage effect of the slope near the empty surface under the action of the earthquake was more obvious than that of the center of the slope. [ABSTRACT FROM AUTHOR]

This study was undertaken in order to analyze the dynamic stability of the slope supported by frame structures with prestressed anchors under earthquake. Taking a mid-span column unit as the object, the dynamic earth pressure on the supporting structures by considering the slope acceleration amplification effect was analyzed, then the supporting structures were simplified, and the prestressed anchors were treated as the dynamic earth pressure on the supporting structure and the inertial force of the supporting structures in the same direction, so the simplified dynamic response model of supporting structure was established. The force method was used to solve the axial force of the anchors. Then the source of the axial force of the anchors was analyzed and range of anchoring area of anchors was solved. The horizontal soil strip was taken as the horizontal soil layer within the range of anchoring area of anchors. The vertical soil strip was taken as the vertical soil layer corresponding to the sliding surface of the horizontal soil strip. According to the failure mode of the slip surface of the soil slope that a dynamic stability model of the slope was established, by considering the influence of the vertical component of seismic action, on the basis of quasi-static method, the horizontal slice method and the vertical slice method were used to derive the slope dynamic stability coefficient calculation equation. Finally, using the algorithm in this paper and the finite element software Geo-Studio, the actual engineering examples were calculated. The results show that the algorithm in this paper has a certain degree of reliability, and can be used for this kind of engineering design and provide corresponding reference for the dynamic stability research of frame structures with prestressed anchors. [ABSTRACT FROM AUTHOR]

Built heritage is incessantly exposed to natural disasters including numerous earthquakes. Therefore, it is important to take measures to reduce vulnerability and increase the protection of buildings depending on the exposure to seismic hazard and the importance of the building. Studying the history of construction reveals examples of building constructions aimed at protecting against earthquakes. For this reason, such examples are presented here, starting with the buildings from the distant past until now. The documentation related to the action of earthquakes throughout history and the procedures in planning the building protection measures in order to preserve the heritage from dilapidation were commented. The paper, also, presents some examples of incorrect use of materials and construction technologies that damage the original structural fabric, and thus, the value of a certain cultural property.