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AbstractNowadays, the use of deep foundations in various civil engineering projects, especially in marine and coastal structures, has been increasing. One type of deep foundations are helical pile foundations, which have gained significant attention in recent decades. This research investigates the load–displacement behavior of different helical pile configurations regarding geometry, i.e., helix diameter and spacing ratio (S/D) in two different soil densities under pullout and compressive loading conditions via the FCV-AUT device. Babolsar sand from the southern coast of the Caspian Sea was utilized for advancing this study. Additionally, four full-scale pile tests were conducted on the Caspian Sea coast under both grouted and non-grouted conditions for pullout and compressive loading. The results indicate that increasing the helix diameter, soil density, and S/D ratio enhances the compressive load-bearing capacity. However, in tensile loading, the ultimate load decreases with an increase in the spacing ratio. Furthermore, the grouting process in the three-helix pile exhibits better performance compared to the two-helix pile, potentially increasing the pile capacity up to 30%. In conclusion, the results obtained from the FCV device, utilizing scale theory, have been generalized to the large-scale pile test results in the field, are representative of in agreement and compatible. [ABSTRACT FROM AUTHOR]

Piled rafts and pile groups are the common types of deep foundations for tall buildings subjected to combined loading. Their complex behavior made their design and analysis very complex and sometimes uneconomical. This paper explores the distribution of lateral load on piles within a piled raft and pile group under a constant vertical load. The study utilized experiments with small-scale models of piles and rafts to observe the behavior. The response of each pile was recorded and analyzed with respect to lateral displacement. The results indicated that in the case of piled rafts under lateral load, the rear piles are resisting more load than the front piles, unlike in pile groups where front piles carry more load than rear piles. This behavior continued until the number of piles reaches nine, thereafter the load-carrying behavior shifted, and front piles began to carry more lateral load. The reason behind this shift is that as the number of piles increases, the raft contact pressure decreases and subsequently decreases the stiffness of soil below raft and hence the piled raft starts behaving as a pile group, where front piles carry more lateral load. [ABSTRACT FROM AUTHOR]

In any high-rise building construction based on piles, it is essential to correctly evaluate their response when subject to high loads to avoid oversizing and consequently high costs. This work falls within the framework of the FONDASILEX project, which studies the behaviour of the pile foundations and the soil within the 'Silex2' tower project built in the Part-Dieu district in Lyon, France. This paper presents the geotechnical instrumentation executed for the foundations and the soil to enable the real-time monitoring of their behaviour. It details its conception, execution and limits. Five different types of electrical and unconventional sensors, including the fibre optic technique, which is based on reflectometry by Rayleigh scattering, were employed. This instrumentation allowed us to measure the soil settlement, the applied load at the head of the pile and the induced deformation in the concrete. The obtained measurements showed good agreement between all the sensors and were compatible with the real applied load. The results of this monitoring completed with an additional specific study to characterize the soil will be used in a future study to calibrate numerical models simulating the behaviour of high-rise building foundations. [ABSTRACT FROM AUTHOR]

The vibration energy of the track slab can be converted into electric energy for wireless sensors by piezoelectric energy harvesters. A track laminated circular plate harvester (TLCP harvester) is designed in this paper based on foundation excitation. The central frequency of the harvester is 222 Hz, which is matched with the 222.8 Hz of the track slab. The stiffness curve, damping, equivalent capacitance, and electromechanical coupling coefficient of the harvester are obtained through the experiment. The harmonic balance method and Runge–Kutta's voltage results are consistent with the experimental results. The frequency responses verify the jump phenomenon and soft characteristics. The experiment results show that the maximum output power is 8.07 mW under 7 kΩ load resistance, and the maximum RMS power is 0.3804 mW under 5 kΩ load resistance. This paper develops a safe and high-efficiency piezoelectric energy harvester for track slabs. [ABSTRACT FROM AUTHOR]

Sediment scour numerical simulation plays a critical role in the design of water-resistant foundation engineering, and this paper addresses a significant gap in most related studies, which often overlook the transformation of sediment and struggle to identify the actual riverbed obscured by yielding bed and suspended load. To tackle this challenge, a comprehensive sediment model based on the meshless Smoothed Particle Hydrodynamics (SPH) method was developed. Firstly, to enhance computational efficiency and mitigate the high cost of Fluid-Solid Interaction (FSI) between water and sediments, cohesionless sediment grains were modelled as non-Newtonian fluids, with yield strength determined according to a combined strength criterion. Subsequently, sediment transformation and identification were determined based on sediment particle velocity and shear stress, with the seepage force driving yield sediment particle motion at the interface. The effectiveness of this comprehensive sediment model was validated through comparison with three scour experiments. The results show better agreement between the model and experimental data, with a root-mean-square error of less than 2.17% in scour morphology simulation and successful identification of the actual post-scouring bed surface in each case. However, the free surface simulation in this model still exhibits slight error, with a root-mean-square error of less than 8.35%. [ABSTRACT FROM AUTHOR]

AbstractThis study introduces a computer simulation framework aimed at analyzing the flexural vibrations of sandwich structures comprising a polymer core sandwiched between two face sheets reinforced with graphene oxide powder (GOP) nanocomposites. The sandwich structures are situated on an auxetic concrete foundation, incorporating sophisticated theoretical formulations to approximate the three-dimensional displacement fields of GOP-reinforced rectangular plates under varying loading conditions. The research addresses the complex interplay of material properties and geometric configurations, crucial for optimizing the structural performance of advanced composite materials in practical applications. The computational model integrates analytical techniques to predict the dynamic behavior of the sandwich structure’s flexural vibrations. Key parameters such as the dispersion of GOP within the polymer matrix, and the auxetic properties of the concrete foundation are systematically varied and analyzed to understand their impact on the overall structural response. Results from the simulations provide insights into the natural frequencies of the GOP-reinforced sandwich structures, offering valuable data for design engineers and materials scientists. The study underscores the potential of graphene oxide powder nanocomposites in enhancing the mechanical performance of sandwich structures, particularly when supported by innovative foundation materials like auxetic concrete. Future research directions include validation and further refinement of the computational model to accommodate additional complexities and real-world conditions. [ABSTRACT FROM AUTHOR]

AbstractThis paper presents the results of numerical predictions for an instrumented piled raft foundation of a tall building in tropical soil. The analysis was performed using 3D finite element analysis and included a comparison of foundation settlements, pile loads, skin friction mobilisation, and raft-soil contact pressure. Initially, the geotechnical model was defined based on field and laboratory test data to conduct a Class A geotechnical prediction. Subsequently, the soil parameters used in the numerical model were re-evaluated to match the measured settlements, aiming for a Class C prediction. The study discusses the main factors that affect the accuracy of the computed settlements, providing valuable insights for foundation designers. Additionally, it highlights the significance of considering the pile-soil-pile and raft-soil-pile interactions in the design of the piles beneath the raft, as these interactions impact the mobilisation of the pile skin friction at different depths. [ABSTRACT FROM AUTHOR]

Inclined pile foundations are commonly adopted in the support of wharf, harbor, bridge, and wind turbine structures. In the context of offshore wind turbines, inclined piles are typically arranged symmetrically around a circle with an elevated pile cap above sea level, referred to as an elevated pile-cap foundation. However, limited research exists on the impedances of inclined pile foundations with elevated pile caps. In this study, a theoretical model was developed that incorporates a homogeneous soil half-space and an inclined pile foundation with an elevated pile cap. The pile and soil half-space were modeled as Euler-Bernoulli beams and linear-elastic continuum, respectively. The soil's contribution to the pile's dynamics was represented by the receptance matrix, established at discrete interactions points along the pile's embedded section. The effects of the rake angle and scour depth on the dynamic impedances of the inclined pile foundation with an elevated pile cap were investigated. It was observed that the peak frequency of impedance shifts to a lower value as the scour depth increases; whereas the peak frequency shifting effect is less prominent when the rake angle changes. The impedance of the elevated pile-cap foundation is more sensitive to the pile's rake angle compared to the scour depth. [ABSTRACT FROM AUTHOR]

This study aims to prepare an anti-washout grout using marine soft clay to stabilize the wind power pile foundations. The cement, hydroxypropyl-methyl cellulose ether (HPMC), and sodium silicate were chosen as the main materials to modify the marine soft clay, and the fluidity, bleeding rate, setting time, rheology, anti-washout characteristics, and compressive strength were investigated. The results showed that high cement content, HPMC, and sodium silicate decreased the workability of grout while enhancing the washout resistance. The addition of HPMC and sodium silicate would increase the yield stress and plastic viscosity of the grout. The sodium silicate content was the key factor influencing the early strength, while the cement content and HPMC affect the later strength. The microstructures including the morphology of C-S-H gels and the content of ettringite and calcium hydroxide significantly changed with the addition of sodium silicate, and Friedel's salt was observed through the microstructure analysis. This study can provide effective guidance for the utilization of marine soft clay, the preparation of anti-washout grout, and the control of pile foundation stability. [ABSTRACT FROM AUTHOR]

Micropiling is an extensively used method for improving the stability of building foundations and load-carrying capacity of the soil. Unlike regular piling, it can be employed without pile driving equipment and, hence, it is a versatile option of soil reinforcement under space-restricted situations. Since, it is an economical and easy to implement option for soil improvement, this paper intends to study the improvement in bearing capacity and settlement behaviour of a fly-ash bed using fine micropiles under isolated footings, for low-cast and lightweight structures. Fly-ash, a by-product of coal-fired power plants, is used in the experiment because it is extensively used as a filling material for housing projects in low-lying areas and pavements. Micropiles were installed underneath the footing as well as beyond the periphery of footing with varied spacing and extent ratio. The results are depicted through two dimensionless constants, namely bearing capacity ratio (BCR) and settlement reduction factor (SRF). Significant improvements have been observed in load-carrying capacity and settlement potential due to decrease in spacing and increase in lateral extent of micropiles. The optimum configuration of spacing and lateral extend achieved 135% bearing capacity improvement with 71% decrease in settlement. [ABSTRACT FROM AUTHOR]

The pile–soil–raft interactions remain a daunting problem in the study of piled-raft foundations. A simple analytical continuum approach is implemented in the present research to analyse the interaction between two granular floating piled-rafts. The formulation uses the equations of Mindlin and Boussinesq for the estimation of the displacements for forces in the interior and on the surface of the continuum. Settlement influence factor, interaction factor, the normalised shear stresses along the granular pile (GP)-soil interface, the percentage load shared by GP, the percentage load transferred to the GP base, and the normalised contact pressure distribution underneath the raft are evaluated and presented for design. [ABSTRACT FROM AUTHOR]

Analysis of a machine foundation system subjected to harmonic and pulse loading is investigated by modeling it as a linear elastic-perfectly plastic single degree of freedom (SDOF) system. Pulse loading, an idealization of explosion/blast, is represented by modified Friedlander's equation having both positive and negative phases. Analytical expressions are derived for equations of motion to obtain the response of SDOF system under combined action of harmonic and pulse loading in the form of displacement-time plots. Results show noteworthy influence of negative phase of pulse loading on the displacement of SDOF system and suggest that this should not be neglected by idealizing the explosion with the help of a triangular pulse loading. The developed solution and the displacement-time histories can help in the analysis and design of a soil-foundation system undergoing combined harmonic and pulse loading (such as a machine foundation). [ABSTRACT FROM AUTHOR]

A one-g shake table experiment was performed to reveal the failure mechanism of the pile group in sloping liquefiable soils with crusts. The results show that the shallow saturated sand exhibits the alternate behavior of dilatancy and shrinkage, which induces high-frequency peak acceleration. In addition, larger PGA tends to transfer vulnerable positions of the pile in the liquefiable layer from the shallow layer to the interface. Moreover, the pile group effect mainly manifested in piles at the bottom of saturated sand and pile-head during strong earthquakes. [ABSTRACT FROM AUTHOR]

Pile foundations may be exposed to torsional loads caused by horizontal eccentric loads brought on waves, wind and earthquakes, as well as axial load brought on by supporting superstructures. This paper highlights a recent strategy to modify piles known as the finned pile. A series of experimental tests were conducted to increase the torsional capacity of a single pile with/without fins in sand under the influence of vertical loads (V), torsional loads (T) and combined loads (T → V), these experiments involved altering fins' length, width, shape, and number and knowing the effect of these variables on the piles' maximum torsional capacity. The vertical load-displacement response and the torsion-rotation response have been observed. The results showed that fins improve piles' torsional capacity. It also showed that on piles' maximum vertical capacity for independent vertical or torsional loads is different from that of piles under combined loading. It was found that fins' optimum geometry is that their length equal to 0.6 of the embedded pile's length and their width equal to the pile's diameter, where piles' maximum torsional capacity was (4.12 and 7.36) N.m for regular and finned piles, respectively. Fins increased piles' maximum torsional capacity by about 79%. [ABSTRACT FROM AUTHOR]

Pile foundations are provided for structures, where soil at the top layers possesses low bearing capacity. A comprehensive understanding of pile foundation located in liquefiable soils is a key requirement to enable designer to arrive at an economic design and for safe performance of structure during its intended service life. The failure of various structures on pile foundation system in liquefied soil subjected to earthquake load shows limitation of present methodologies available for design. Hence, study of pile foundations in liquefiable soil under earthquake loading attracted attention of researchers over many years. In addition, many governing factors, as compiled by researchers during analysis and design of pile foundation in liquefiable soils, need to be critically analysed. Therefore, in present paper comparative aspects of various issues addressed by different researchers are presented. It briefs about various International Codes followed in design and analysis. This review article also provides analytical study/numerical model developments, and experimental works performed by various researchers with an effort to bring out the progress in analysis and design. The current paper also discussed various behavioural issues, design aspects, recommendations by researchers dealing with proablems of pile foundation considering liquefaction condition of soil and some exemplary cases. [ABSTRACT FROM AUTHOR]

Considerable research has been endeavoured to examine the responses of piled raft foundation (PRF) under gravity load. In reality, PRF often encounters combined vertical (V), horizontal (H) and moment (M) load simultaneously due to wind, earthquake and wave load along with dead load of the structure, and vertical soil pressure. Present study aims at a scaled-model test on the PRF subjected to V-H-M loads to investigate the lateral responses of PRF due to the interaction of loadings. The scaled model tests are conducted in Agartala sand with a relative density of 30%. Effects of relative stiffness raft with respect to soil, the length and spacing to diameter ratio of the pile, number of piles in a group and non-uniform pile length configuration on the lateral response of PRF are studied. Results indicate that the V load in V-H-M loading has a significant influence on the lateral response of PRF. Further, a substantial influence of other parametric variations on lateral response is also observed. Furthermore, a numerical model is also developed and validated based on experimental results that substantiate investigation on prototype foundation. Finally, the load-sharing behaviour of prototype PRF is also studied through the validated numerical model. [ABSTRACT FROM AUTHOR]

The construction of modern city consists of many underground facilities, and one major concern is how to construct them safely and efficiently. Thus, the excavation-induced pile response needs to be evaluated. Dual-row batter pile wall (DRBPW) exhibits better performance than traditional dual-row vertical pile wall (DRVPW) in foundation pit engineering. However, the study of single pile subjected to excavation-induced soil movement behind DRVPW is rather limited, needless to say that of the DRBPW. An explicit finite difference method (FDM) was utilized to obtain the responses of isolated floating single pile (IFSP) near deep excavations braced by DRBPW. The responses of IFSP in the vicinity of foundation pit reinforced by DRBPW were compared to that of the DRVPW. The pile length, distance of pile from wall, excavation depth, working load, and Young's modulus of pile were considered in the parametric study. The conclusions were as follows: (1) The DRBPW can minimize the influence on the existing pile; thus, the induced lateral displacement and bending moment of pile retained by DRBPW are smaller than that of DRVPW. (2) The excavation depth, pile location, and pile length have significant influence on the responses of IFSP adjacent excavation, while the working load and Young's modulus of pile have diminutive influence. (3) The influence zone induced by excavation can be divided into two areas. The primary influence zone is the severely affected area where the induced deformation and bending moment are remarkable. The secondary influence zone is the moderately affected area where the induced deformation and bending moment are mild. The primary influence zone is within twice of the excavation depth. The secondary influence zone is 2.0–3.0 times that of the excavation depth. (4) The pile toe of IFSP has considerable lateral displacement during excavation, and attentions should be paid to the whole pile shaft during construction. [ABSTRACT FROM AUTHOR]

This article discusses experiences of applying the source-to-sea approach, contextualized to source-to-lake, in the Lake Hawassa sub-basin of the Ethiopian Rift Valley, particularly for the purpose of generating in-depth knowledge on sediment flows, building a geographically relevant comprehensive stakeholder and governance analysis and using this to design impactful interventions that can reduce sediment flux into Lake Hawassa. The source-to-sea approach has proven to be a useful and flexible for evaluating sediment management in the context of a sub-basin such as that of Lake Hawassa. [ABSTRACT FROM AUTHOR]

We examine how teacher leaders (TLs), working in a low-income urban elementary school, supported their colleagues to learn how to collect quality formative data and to discuss it in collaborative conversations in order to make their students’ learning visible. The TLs faced challenges reflecting consequences resulting from the district’s high stakes accountability policies restricting teachers’ agency with instructional decision-making and limiting their definitions of data as summative test scores. We document how the TLs worked to reframe teachers’ understanding of data to include evidence of student thinking and supported their colleagues to reclaim teaching as professional versus technical work. [ABSTRACT FROM AUTHOR]

This study examines the experiences of incarcerated mothers who participate in a faith-based parenting program at a women's prison in the United States. Thirty-three women participated in four focus groups. Using a grounded theory framework, four major themes emerged from the analysis, including building foundations, guilty mom, on the mend, and opening the lines of communication. Overall, the findings highlight numerous benefits of the program for incarcerated women's relationships with their children, their ability to reframe the experience of motherhood, and their personal growth. A theoretical model for others who must parent 'from a distance' is proposed. [ABSTRACT FROM AUTHOR]

In the area of water-rich sandy soil, the disaster of water and sand leakage (WSL) is easy to occur in foundation pit engineering, which leads to disaster such as surface collapse. Grain size and composition affect the disaster degree of WSL. In order to study the WSL in foundation pit of water-rich sandy soil with different grain size distribution, three groups of samples with different grain size distribution are prepared according to the median particle size (d50). A visual experimental device is designed to simulate the process of WSL after defect appears at the water-stop curtain and DEM-CFD coupling method is used to simulate the experimental process to explore the influence of different grain size distribution on time, morphology and process of WSL. Results show that: (1) The WSL process of foundation pit can be divided into three stages: the extension period, the stabilization period and the mutation period. (2) As the content of coarse particles increases, the sandy soil is more likely to form soil arch. (3) In terms of the WSL erosion range, Soil A with mostly coarse particles < Soil B with uniform particles < Soil C with mostly fine particles. [ABSTRACT FROM AUTHOR]

Major structures like offshore platforms, wind turbines, transport infrastructure, tall buildings, etc., resting on soft compressible clays, are often supported by pile foundations. Apart from usual vertical loading (dead load, live load, etc.), these piles are subjected to significant cyclic loads arising from actions of waves, ship impacts, winds or moving vehicles. Under such circumstances, the lateral mode of cyclic loading is predominant and affects the overall foundation stability. Such repetitive loading leads to stress reversal in adjacent soft clay initiating progressive degradation in soil strength and stiffness, deteriorating the pile capacity with unacceptable displacements. Although several past studies investigated the response of single pile under lateral cyclic loading, a detailed investigation on pile group in clay subjected to cyclic lateral loading, which is of immense practical interest to field engineers, is yet to be carried out. In this paper, in-depth study has been carried out by developing a three-dimensional dynamic finite element model. Comparison of the computed results with available test data validates the numerical model. Extensive parametric studies with field data indicate that both the axial and lateral pile capacities and displacements have been significantly influenced by the cyclic loading parameters. Relevant design curves are also constructed. [ABSTRACT FROM AUTHOR]

Traditionally, temperature control for massive concrete structures during the construction phase is based on experience instead of using advanced methods such as predictive control method. In this paper, a predictive control method with a hybrid data-based artificial neural network (ANN) model is proposed. The main parameters of the numerical model are identified based on the data measured from the site. Since the limitation of the measured data, a rich dataset is generated by the numerical model with the identified parameters. Finally, a hybrid data-based ANN model for predicting the temperature indicator of massive concrete is developed. A case study in which the temperature control of concrete in a real bridge anchorage foundation construction in Southwestern China is conducted. Results show that the maximum temperature of concrete can be controlled around the target temperature by the proposed method. The average temperature decline rate decreases from 0.19 °C/h to 0.14 °C/h in the period of 120 h (i.e., from 60 h to 180 h after the concrete pouring) at a sudden decrease of 8 °C in environmental temperature, thereby enabling a significant reduction in the risk of concrete cracking. [ABSTRACT FROM AUTHOR]

The relative density of seabed determines its bearing capacity and affects the site selection, construction, and maintenance of offshore projects. As the modal-identification-based method for monitoring pile foundation scour depth does not account for the relative density of seabed, it cannot be implemented in engineering practice. Therefore, experiments and finite element simulations of a pile–soil model with different scour depths were conducted in this study to update and verify the modal-identification-based method to account for relative soil density using the Winkler foundation model. The results show that for a given scour depth, the average error decreased as the relative soil density increased, and for a given relative density, the average error decreased as the scour depth increased. The accuracy of the updated method was then improved according to the variation of the average error according to soil density and shown to exhibit strong engineering applicability. [ABSTRACT FROM AUTHOR]

This study investigates the interplay between stormwater infiltration devices, shallow groundwater and underground structures (sewer pipes and building foundations) at the neighborhood scale. Considering a hypothetical urban area, different scenarios are designed by varying the underground components taken into account within two soil types. For the least permeable soil, interactions with groundwater reduce the infiltration within devices (−99 to −151 mm/y) and increase the transpiration in surrounding areas (+42 to +50 mm/y). For both soils, the overall water table rise due to infiltration and mounding beneath infiltration devices increases groundwater drainage by sewer pipes and draining systems (+7 to +96 mm/y) and the water elevation differential between opposite walls of impervious structures (up to +1.5 m). In turn, underground structures strongly modify groundwater flow. For the least permeable soil, this directly affects groundwater influence on infiltration and transpiration and thus the overall effects of infiltration strategies at the neighborhood scale. [ABSTRACT FROM AUTHOR]

This paper estimates the effect of a pre-hole filled with high-damping material on the inelastic response spectrum of Integral Abutment Bridges (IAB) with pile foundation. The hysteretic response of the pile, described by a Winkler beam model, is obtained from the piece-wise definition of the subgrade stiffness, calibrated on experimental data. The pre-hole with damping pre-hole determines a reduction of the demand spectral acceleration. The force modification factors of the acceleration response spectrum of the bridge superstructure under a large set of strong/motion earthquakes are estimated. The force-reduction factors for the elastic design of IABs with damping pre-hole are proposed. [ABSTRACT FROM AUTHOR]

Fixed pile-founded offshore platforms require careful consideration during their analysis, design, and assessment because uncertainty in design variables can decrease the reliability of the structures. The present study investigated the sensitivity of seismic engineering demand parameters to stochastic and epistemic modelling variables for a fixed pile-founded jacket platform. Tornado diagram analysis and the first-order second-moment techniques were employed to examine the effects of 11 variables on engineering demand parameters under real earthquake loads and the importance of each variable was determined. As the nonlinear response of the pile foundation is a crucial source of nonlinearity in offshore platform response, a robust model considering soil–pile–structure–fluid interaction was employed. This study varied from previous research as it employed a three-dimensional model, fluid environment modelling, and earthquake actions in perpendicular directions. These differences resulted in more realistic approximations of the seismic behaviour of the platforms. It was found that the effects of different variables, especially water depth, should be considered in order to produce better performance evaluations of a structure for a more efficient and cost-effective design. [ABSTRACT FROM AUTHOR]

III Roman London à An inventory of the Historical Monuments in London: III Roman London i (London 1928). 3 R. Merrifield, I The Roman City of London i (London 1965); I London City of the Romans i (London 1983). Furthermore, he was very much involved in the excellent display on Roman London at the Museum of London, which - until the museum's temporary closure in 2022 - gave an impression of what it was like to live in a fully Roman city. [Extracted from the article]

This paper proposes a coupled fluid half-space - strip foundation - poroelastic half-space vibration model to study how dynamic water pressure caused by strip vibration affects foundations operating offshore. Both vertical and rocking vibrations are considered. The governing equations of the problem are obtained using the Biot's theory and proper boundary conditions at the seawater - seabed interface. The solution of the strip vibration problem is obtained by an integral equation method. The results are expressed in terms of dual integral equations that are converted into Fredholm integral equations and solved numerically. Selected numerical results for the vertical and rocking dynamic impedance functions are examined based on different poroelastic materials and exciting frequencies. The results show that for a rigid strip foundation, the presence of a seawater half-space can increase amplitude of the dynamic vertical impedance, but decrease amplitude of the dynamic rocking impedance. [ABSTRACT FROM AUTHOR]

Libraries have evolved from collections to convening spaces over the past 30 years and the next evolution of libraries will see library leaders and workers advance community building. Leveraging the centrality of their spaces and the appreciative view their communities extend, library leaders and workers can build on the authentic concern we hold for our community's wellbeing by fostering libraries as places for community transformation, regardless of library type. This article applies a powerful methodology for building community that assumes that conventional ways societies realize change is flawed because it fails increasingly large numbers of our citizens, despite our collective efforts to double down on what is not working for most of us. The shift from a retributive agenda to a restorative one where citizens reclaim their power and leaders' job is transformed from solving problems to convening powerful conversations becomes the work of libraries and leaders. It should be noted that this article grew out of a series of conversations between the author and Peter Block, who advised on the content and structure of the paper and whose book Community: The Structure of Belonging provides the foundation of community building that this contribution adapts to a library leadership context. [ABSTRACT FROM AUTHOR]

Component reliability and sensitivity analysis of soil-slope combined-reinforcement deterministic designs are studied using a hybrid numerical-probabilistic method. Major components are qualitatively identified with numerical simulations to avoid redundancy evaluations. Quadratic polynomials as response surfaces are stepwise regressed to predict component load effects. Major component resistances of supporting structures are calculated in states of soil ultimate equilibrium and maximum allowable deformations obtained according to building and foundation types. Component performance functions (PFs) are established based on component failure models and soil-mass deformation properties. Reinforced slope stability reliabilities are calculated with first-order second-moment and design point methods. The reinforcement probability safety indicated by component reliability indices is adopted to check whether the deterministic design needs improvement. This methodology is applied to a loess slope reinforced by combined supporting. The resultant reliability indices of the slope imply some improving treatments should be made. Sensitivity analysis shows some variable variation has a more significant impact on the PFs; inversely signed sensitivity coefficients indicate that the equilibrium point between PFs should be considered when modifying parameters. Stable monitoring results of modified design implementation indicate that probabilistic analysis of component stability is necessary for some slope-treatment designs with distinct probability distribution variables. [ABSTRACT FROM AUTHOR]

This paper presented trilinear load transfer models for both pile shaft-–soil system and pile tip-soil system to analyze the load–settlement relationship of bored pile in loess area. Based on the differential equation of load transfer, the load transfer functions in different stages were deduced. Furthermore, combined with the trilinear model of pile tip-soil system, the load-settlement functions were obtained and the calculation method was completed. A static load test for a single pile was then carried out to obtain the required pile-soil system parameters, and the calculated results were presented and compared to those of the static load test, proving the feasibility of the proposed method. Moreover, the influence of each pile-soil system parameters on the load–settlement relationship of single pile was studied, and the results provide guidance for the pile foundation engineering in loess area. [ABSTRACT FROM AUTHOR]

Piled raft foundation (PRF) is a cost effective and sustainable foundation option which can reduce the total and differential settlement, and improve the bearing capacity of the foundation in case of high-rise superstructures or marine structures. This study mainly focuses on a parametric analysis of PRF and also checks the impact of various design parameters on the structural and geotechnical aspects of PRF including the settlement of PRF and its components, raft-soil contact behaviour, bending moment, axial stress on pile, soil stress and settlement in different directions etc. To understand the contribution of piles in PRF, two factors such as relative improvement in the stiffness and settlement ratio are also evaluated. The results of the present study indicate that the differential and reference settlement can be controlled by the addition of piles under the raft, whereas the value of normalized differential settlement remains increasing with an increase in the pile spacing to diameter (s/d) ratio. In case of raft-soil contact behaviour, the contact pressure increases if the raft width is increased, but the rate of increment is prominent in case of a higher number of piles. The raft is showing both the sagging and hogging bending moment and as s/d ratio increases, bending moment also tends to increase. [ABSTRACT FROM AUTHOR]

Reinforced Concrete (RC) frame buildings with shear wall are widely used in severe seismic zones. However, the underlying soil-foundation system modifies the conventional fixed-base natural period through imparted flexibility. The currently available relationships for the modified natural period are mostly applicable to shallow foundations. Hence, those are not suitable for RC frame-wall buildings with pile foundation. Based on an Artificial Neural Network (ANN) architecture model, the current study establishes a relationship for the effective natural period of such buildings. A comparison of the proposed relationship with the existing ones demonstrates its applicability to RC frame-wall buildings on pile foundation. [ABSTRACT FROM AUTHOR]

Radon-222 contributes to half of the natural radiation exposure of humans and is one of the main causes of lung cancer. Of particular importance for humans is the exposure to radon-222 indoors, which enters living and working areas from the soil air, e.g. through cracks in the foundations of buildings. An easy and efficient way to minimise indoor radon in dwellings can be achieved through ventilation. How meteorological parameters and the geological background can influence ventilation efficiency in reducing indoor radon has not yet been fully investigated. Therefore, a decentralised ventilation system was installed in an unoccupied flat located in a former uranium mining region to analyse the effect of already existing ventilation modes on indoor radon activity concentration. It is aimed to assess 22 different ventilation experiments that were performed within the time period of one year. Even with a strong seasonal trend with significantly lower indoor radon activity concentrations in summer compared to winter, the decentralised ventilation system was able to reduce indoor radon by up to 83 %. Thereby, strong dependencies on the experimental parameters such as ventilation type or performance level of the fans were found. [ABSTRACT FROM AUTHOR]

Structure-canyon-structure interaction is investigated using a whole model of two shear walls supported by rigid foundations on both sides of a semi-circle river-canyon embedded in a homogenous half-space. A closed-form analytical solution is presented for the model response to incident plane SH-wave based on the wave function expansion method. The analysis focuses on the effects of the structure-canyon-structure interaction. Structure-canyon-structure interaction depends not only on the distances between canyon and structures but also on the frequency of the incident wave and the incident angle. For inclined wave incidence, the response of structure on the incoming wave side is always larger than that of the outgoing wave side. The peak of building foundation response can be enlarged by about 69.68%, and the peak relative response of the building can be amplified by 60.40%. The interaction cannot be ignored, even when the distances between the canyon and the structures are very large. The canyon response is highly related to the dynamic characteristics of the structures on both sides of the river. This paper is an attempt on site–city interaction, a problem closer to practical real problems. The model and the results may be useful for obtaining insight into the effects of structure-canyon-structure interaction and interpreting the observed response in buildings and seismic response estimation in general. [ABSTRACT FROM AUTHOR]

Piled raft foundations are the composite construction of a spread foundation and a few number of piles that are usually used in soft soils to compensate the weakness of a raft in satisfying the design requirements. Due to the complex behaviour of piled raft, it is necessary to take into account a number of factors such as pile geometry and arrangement, raft thicknesses, soil properties and loading condition in the design. In this study, a parametric study has been conducted by a three-dimensional finite-element method considering the full interaction between the components of piled raft foundation. The underlying soil consists of Babol clay in drained condition with various stiffness and plasticity, determined from the results of a geotechnical investigation. The results of numerical analyses show that the bearing capacity of piled raft obviously increases with increasing pile length, pile spacing and raft thickness, especially in stiff clay. The effect of load type is more significant for the differential settlement and pile loads than other parameters. Finally, the advantages of using an optimum design method are examined in a special case of analyses and a case history. [ABSTRACT FROM AUTHOR]

Industrial and construction wastes are often stored and heaped up in a large-scale mound on the storage yard. The load generated to the foundation soil tends to be wide in area, long term in duration and high in intensity which requires higher bearing capacity of foundation soil. The step loaded surcharge preloading method is often adopted to consolidate the foundation soils and thus improve their engineering properties. To reasonably evaluate the stability of the foundation soils, the consolidation effect is therefore required to be considered when estimating the increased bearing capacity of the foundation soil. The stress path method is adopted in this paper to calculate the strength development of the foundation soil during the consolidation process. An analytical method was proposed to estimate the bearing capacity of the foundation with respect to consolidation effect. FEM analysis was used to verify the reasonability and validity of the proposed method. Two case studies were also conducted to verify the accuracy of the method. The safety factors obtained by the proposed method could be used to indicate the possibility of failure coinciding with field observations. The proposed method was therefore recommended to be used to predict the stability of the similar engineering projects. [ABSTRACT FROM AUTHOR]

Vibrations due to heavy construction work continue to be a major concern for museums. Although there has been an increase in research on the effect of vibrations on objects of cultural heritage in recent years, selecting measures to protect collections and remain open during construction work continues to be difficult because of a lack of data on what objects can actually withstand, the complexity of vibration loads, and the uniqueness of each situation. The major renovation of the Central Library in Liverpool, UK, which shared walls with the World Museum and Walker Art Gallery, both of which belong within National Museums Liverpool, showed how museums and other institutions can successfully deal with such situations. An integral approach was taken, beginning with an extensive risk analysis to determine which objects could remain on display, which needed extra protection and regular condition monitoring, and which had to be removed. The museums then negotiated a vibration protocol and action plan with the contractors, including continuous monitoring, and trigger levels requiring consultation or work stoppage. Vibration data were also stored and used for later analysis. This integral approach was successful in protecting the collections on exhibition, with only two incidents of reported damage directly related to vibrations. A combination of museum staff experience, excellent communications with the contractors, and some flexibility in defining vibration limits provided a successful recipe for both museums. The analysis of the vibration data using the basic engineering concept of the Palmgren-Miner rule, supports a more flexible approach to setting vibration limits based on recently published guidelines. [ABSTRACT FROM AUTHOR]

During construction of a 6 km long railway tunnel close to historic churches in Stockholm, a preventive monitoring model was applied for ensembles of large-scale immovable ecclesiastical artworks. Construction work such as blasting and pile-driving took place during five years under or very close to these immovable works of art. In Sweden, risk assessment related to construction work is focused on risks associated with the building; meanwhile, there is no common approach for protecting the immovable historic works of art and architectural surfaces. This paper discusses how a preventive model for vibration monitoring on immovable artworks was developed and used as well as how the preventive purpose was perceived by different stakeholders during and after the tunnelling work. Experience from this project concludes that monitoring that includes uniform visual inspection becomes crucial for being able to protect the artworks. The concept of vibrations standards relying on fixed numbers of critical vibrations levels for mitigating the effects of vibration on immovable art can be questioned based on experiences from this project. [ABSTRACT FROM AUTHOR]

A rationale and model lesson for young children that explores the many dimensions of wood construction. [ABSTRACT FROM PUBLISHER]

The old city centers of many major cities represent a great challenge from a constructive point of view since the foundations of the buildings consist of an aggregation of previous constructions. This endorses thorough monitoring activities during any underground construction. The capabilities of the persistent scatterer interferometry (PSI) can be exploited to cope with these monitoring needs. However, the old city centers represent a very challenging urban scenario since the rooftops are usually filled with air conditioning systems and due to the fact that the streets are usually crowded. This work assesses the applicability of the PSI technique under this challenging scenario. Moreover, it proposes a set of novel classification indexes that allow an objective assessment of the building's health and the impact derived from any activity. They can be applied in deformation monitoring and risk evaluation in urban areas. The applicability of the technique and the proposed indexes is validated in the monitoring of underground construction works in the old city center of Madrid comparing the results against on-ground measurements and identifying the potential and the limitation of the technique. [ABSTRACT FROM AUTHOR]

High-rise buildings in areas with thick layers of sedimentation require deep pile foundations which lead to higher costs. The height, layout and location of high-rise buildings are crucial to reducing costs. The aim of this paper is to propose a cost estimation model for buildings, which includes pile foundation and land cost. The element method for cost control and structural theories are integrated in order to predict costs per m² of floor. Specific soil characteristics have been combined with wind and seismic loads. The result of this study is a cost estimation model that allows for the comparison of these different layouts (building height and depth). The effect of land cost and soil conditions (requiring appropriate pile foundation) on the price per m² of floor can be calculated. The model can support designers, developers and policy-makers in making decisions in the early design stages. [ABSTRACT FROM PUBLISHER]

A model for one-dimensional non-linear consolidation of a soft foundation with an upper crust with depth-dependent additional stress was presented in this paper. The semi-analytical solution of this model with the boundary condition of the pervious top was derived, which was proved by comparing with the classical solution of a one-layered foundation under an instantaneous loading. Then, the effects of the depth-dependent additional stress on the consolidation of the double-layered foundation were revealed. The results show that the depth-dependent additional stress inside foundation has a great influence on the consolidation rate at the former stage and final settlement of the double-layered foundation. If the change of the additional stress along the depth is neglected, an underestimated consolidation rate and overestimated final settlement will be obtained. [ABSTRACT FROM AUTHOR]

This paper shows the results of a numerical analysis carried out using the equivalent frame method, which aimed to investigate the three-dimensional behaviour of masonry buildings with shallow foundations subjected to different settlement troughs on a set of soil types. The obtained results are first expressed in terms of deterministic relationships between the adopted intensity measure (the maximum differential settlement) and a newly defined engineering demand parameter (the vertical drift ratio). Then, following a probabilistic approach, fragility curves pertaining to the modelled masonry buildings are generated, and their usefulness in preventing the occurrence of a serviceability limit state is discussed. [ABSTRACT FROM AUTHOR]

Calculation of heat transfer from building foundations is a computationally intensive three-dimensional problem that can require several weeks to solve using current computing hardware. The Kiva numerical framework was developed to compare foundation heat transfer calculation methods and determine approaches that reduce computation time without sacrificing a balance of capability, ease-of-use, and accuracy. This paper demonstrates the application of the Kiva framework to determine an accurate method of approximating three-dimensional heat transfer effects using two-dimensional coordinate systems. In two-dimensions, problems that would otherwise take days or weeks to solve can be solved in less than a minute. Three existing two-dimensional approximation methods along with a new boundary layer adjustment method are tested across a range of foundation types, shapes, and insulation configurations. The boundary layer adjustment method is shown to provide results within 3% mean absolute deviation from the three-dimensional solution. [ABSTRACT FROM PUBLISHER]

Researchers analyzed data from 14 participants in a collaborative, interarts, intergenerational community partnership project entitled An Evening with Harvey Dunn’s Feminine Images, to understand the effects of the project design on participant learning. The year-long project included collaboration among faculty and students from six disciplines at South Dakota State University (SDSU) in Brookings, South Dakota, using four paintings by artist Harvey Dunn as its inspiration. In addition, partnerships with the South Dakota Art Museum and a local dance studio provided community engagement with diverse age groups. The project created an environment in which an interarts and intergenerational cohort of learners explored diverse learning opportunities within a new context. Rich description from participant experience helped researchers understand how the project’s structural framework was perceived by participants, what the participants learned, and how that learning aligned within Chad Hoggan’s (2016) metatheory of transformative learning. [ABSTRACT FROM AUTHOR]

In this article, we argue that a comparative study of state and non-state terrorism that uses the minimal foundationalist definition of terrorism as its central analytical framework offers a unique and instructive approach for answering the question: “what is terrorism?” To date, most recent comparative case study analyses of terrorism focus on ideologies, political/governance models, structural/contextual enablers, practices, organisational structures, and/or the basis of issues such as trust, belonging, and membership. We uniquely contribute to the growing literature on comparative terrorism studies by comparing and contrasting state and non-state terrorism on the basis of strategic communication vis-à-vis the preparation, execution, and outcomes of political violence (the “terrorism attack cycle”), the instrumentalisation of victims, and fear management. We argue that state and non-state terrorism are co-constituting and co-enabling phenomena, possibly best conceptualised as two bounded and coiled strands of the political violence DNA. [ABSTRACT FROM PUBLISHER]