The long initial and coda waves with small amplitude are often observed in an actual earthquake record. Truncating those wavebands that contribute little to structural responses is helpful to focus on the strong shaking phase and reduce computational cost. In the paper, 157 actual earthquake records and the acceleration time windows constrained by truncation thresholds of Arias intensity serve as input ground motions. A large number of elastoplastic dynamic analyses on a 295 m-high core-wall rockfill dam (CRFD) are conducted using the generalized plasticity model and seismic wave input method. Inspired by fragility equation, the probability curves for the accuracy loss of dam response less than different limits under different truncation thresholds are established, quantifying the destructiveness of the truncated seismic acceleration time windows. Results show that the probabilities are minimally affected by peak ground acceleration (PGA); the allowable tail truncation of earthquake records is much more than the leading due to the asymmetry of seismic waveforms and the cyclic hardening characteristic of rockfill materials; the truncation metric of 0.01-98 % Arias intensity is proved to be effective and robust in accelerating dynamic analyses of rockfill dams with an accuracy loss within 5 % and an average reduction in computational workload of approximately 50 %.

Due to its inherent advantages, shield tunnelling has become the primary construction method for urban tunnels, such as high-speed railway and metro tunnels. However, there are numerous technical challenges to shield tunnelling in complex geological conditions. Under the disturbance induced by shield tunnelling, sandy pebble soil is highly susceptible to ground loss and disturbance, which may subsequently lead to the risk of surface collapse. In this paper, large-diameter slurry shield tunnelling in sandy pebble soil is the engineering background. A combination of field monitoring and numerical simulation is employed to analyze tunnelling parameters, surface settlement, and deep soil horizontal displacement. The patterns of ground disturbance induced by shield tunnelling in sandy pebble soil are explored. The findings reveal that slurry pressure, shield thrust, and cutterhead torque exhibit a strong correlation during shield tunnelling. In silty clay sections, surface settlement values fluctuate significantly, while in sandy pebble soil, the settlement remains relatively stable. The longitudinal horizontal displacement of deep soil is significantly greater than the transverse horizontal displacement. In order to improve the surface settlement troughs obtained by numerical simulation, a cross-anisotropic constitutive model is used to account for the anisotropy of the soil. A sensitivity analysis of the cross-anisotropy parameter alpha was performed, revealing that as alpha increases, the maximum vertical displacement of the ground surface gradually decreases, but the rate of decrease slows down and tends to level off. Conversely, as the cross-anisotropy parameter alpha decreases, the width of the settlement trough narrows, improving the settlement trough profile.

In order to further analyze the mechanical and deformation characteristics of geogrid-reinforced soil retaining wall in the high backfill road section, this study experimentally investigates the effects of retaining wall slope, reinforcement layers, and reinforcement position on the bearing capacity and deformation characteristics of geogrid-reinforced soil retaining walls. The distribution of earth pressure in the reinforced soil retaining wall is also analyzed. The test results indicate that the ultimate bearing capacity of the retaining wall can be effectively improved by increasing the geogrid layers. The overall stability of the retaining wall decreases as the slope increases. When the number of reinforcement layers is consistent, the arrangement of geogrid in the upper part of the retaining wall can better control the deformation of the retaining wall and enhance the overall stability of the retaining wall. Under the vertical load, the horizontal displacement of the upper part of the wall is larger than that of the lower part, and the maximum horizontal displacement of the wall occurs at the top of the wall. The vertical earth pressure is not completely transmitted along the vertical direction but is transmitted downward along a certain diffusion angle. The growth rate of the upper earth pressure decreases gradually compared to that of the lower earth pressure as the load increases.

Deep excavations in urban areas may cause excessive ground deformations, leading to potential damage to the surrounding buildings. To prevent such problems, some techniques, such as the anchored wall systems, are used as a supporting method. This study, based on a large number of data produced by FE simulations and using the MARS approach, first presents a straightforward relation that can predict the maximum horizontal displacement of the anchored wall systems. Then, a simple predictive relation using MARS is established for developing a unique stiffness parameter. Finally, a novel design procedure based on the proposed MARS models, the stiffness parameter, geometric relationships, and recommendations from the FHWA is developed. By following this procedure, one can reasonably estimate the lengths of the anchors, their spacing, and tensile forces. Furthermore, the maximum horizontal displacement of the excavation wall can be accurately predicted and compared with the real value for better safety control of the construction procedure.

In order to explore the mechanical properties of cement-soil wrapped pile support system in soil-rock combination foundation pit support. In this paper, based on a deep foundation pit project in Qingdao, the horizontal displacement monitoring test of cement-soil wrapped pile support system was carried out. Combined with ABAQUS finite element numerical simulation, the foundation support model of cement-soil wrapped pile in soilrock combination foundation was established. The variation rule of bending moment and displacement of cement-soil wrapped pile under different influencing factors is explored, And the reasonable position of the micro steel pipe piles in the cement-soil pile is clarified. The results of the study show that the micro steel pipe piles have the best support with less horizontal displacement when they are located on the excavation side of the foundation pit. With the gradual increase of excavation depth, the horizontal stress of the soil basically increases linearly, which is consistent with the change rule of active soil pressure along the depth direction. Increasing the strength of cement-soil can significantly improve the deformation resistance of the supporting structure. The research results can provide reference for the design and construction of foundation support for soil-rock combination foundations.

Multi-row grouting can be used to repeatedly mitigate the deformation of critical structures such as tunnels. Nevertheless, no comprehensive investigation into the development patterns of soil deformation and excess pore water pressure, induced by multi-row grouting in soft soil, has been conducted to date. To address this gap, this study carried out a field test of multi-row grouting, systematically exploring the evolution and accumulation of soil horizontal displacement (SHD) and excess pore water pressure (EPWP) resulting from multi-row grouting. The findings demonstrated that the grouting process during multi-row grouting exerted reaction and shielding effects on the subsequent grouting for the behavior of soil surrounding the grouting area. The reaction and shielding effects increased proportionally with the number of grouted rows. To predict the SHD induced by multi-row grouting, considering the reaction and shielding effects, this study provided a theoretical calculation method based on cavity expansion theory and the concept of upper and lower bounds and proposed an optimal grouting scheme.

Rubble mound breakwater is a coastal structure, which is constructed to provide tranquil conditions in and around the port areas. Generally, the rubble mound structures are subjected to vigilant waves throughout the year. After the earthquakes of Kobe (1995), Kocaeli (1999), Tohoku (2011) etc. it is observed that the breakwaters can collapse due to failure of foundation and by seismic activity. Hence, in order to assess this problem, the current investigation deals with the study of rubble mound breakwaters and it is behavior against the seismic forces using numerical analysis. A finite element software PLAXIS is used for the numerical simulations. For study, a prototype has been selected and numerical model developed is a conventional rubble mound breakwater. In countermeasure model, the sheet piles in the foundation soil on extreme side of mound were considered. The numerical analyses have been done for constant seismic loading and soil properties. The parameters like vertical settlement and horizontal displacement were determined at different nodes. The vertical settlement was observed to be predominant in the crest region and it was reduced by 38% in countermeasure model. The displacement contours were significantly seen in core and armor units. The horizontal displacement of mound was seen by lateral movement of outer layers and it was 23% lesser for sheet pile reinforced model.