Abstract

To evaluate the performance of dual-row batter pile wall (DRBPW) in deep excavations, a three-dimensional numerical model was established. The plastic hardening (PH) constitutive model in FLAC^3D was adopted, considering the hardening property of the soil. A series of parametric study was conducted to investigate the effect of different factors. By analyzing the maximum lateral displacement, the pile shaft deflection and bending moment of both the leading and trailing row, the effect of inclination angle, pile diameter, penetration depth, and row spacing on the behavior of DRBPW was determined. The following conclusions could be drawn: (1) The bearing capacity of DRBPW is quite larger than that of the dual-row vertical pile wall (DRVPW). With the increase of inclination angle, a substantial reduction of lateral displacement could be observed. However, the beneficial role of batter pile is almost negligible when the inclination angle is not larger than 5°. The recommended inclination degree of the batter pile is 10° to 15°. (2) The maximum displacement of the leading and trailing rows lies at a distance below the pile cap, while the maximum bending moment is located at a small distance below the dredging line. The maximum bending moment of the leading pile is approximately twice that of the trailing one, thereby indicating that the leading pile bear more lateral earth pressure than the trailing pile. (3) The pile diameter, penetration depth and row spacing should be maintained in a suitable range; otherwise, the DRBPW may fail earlier than expected. The slender ratios is recommend to be set not larger than 30. The penetration ratio should not be less than 0.22. The optimal row spacing for the DRBPW is four times the diameter.

摘要

为了评估双排斜桩墙 (DRBPW) 在深基坑中的性能，建立了三维数值模型。^{FLAC 3D}中的塑性硬化（PH）本构模型考虑到土壤的硬化特性，采用了这种方法。进行了一系列参数研究以研究不同因素的影响。通过分析最大横向位移、前排和后排的桩轴挠度和弯矩，确定倾角、桩径、穿透深度和排间距对 DRBPW 性能的影响。可以得出以下结论： (1) DRBPW 的承载力远大于双排垂直桩墙(DRVPW) 的承载力。随着倾角的增加，可以观察到横向位移显着减小。但是当倾角不大于5°时，斜桩的有益作用几乎可以忽略不计。推荐的面糊堆倾斜度为10°至15°。(2) 首尾排最大位移位于桩帽下方一定距离处，最大弯矩位于清淤线下方不远处。前桩的最大弯矩约为尾桩的两倍，表明前桩承受的侧向土压力大于尾桩。(3)桩径、贯入深度和行距应保持在适宜的范围内；否则，DRBPW 可能会比预期更早地失败。细长比建议设置不大于30，贯入比不小于0.22。DRBPW 的最佳行间距是直径的四倍。而最大弯矩位于疏浚线下方的一小段距离处。前桩的最大弯矩约为尾桩的两倍，表明前桩承受的侧向土压力大于尾桩。(3)桩径、贯入深度和行距应保持在适宜的范围内；否则，DRBPW 可能会比预期更早地失败。细长比建议设置不大于30，贯入比不小于0.22。DRBPW 的最佳行间距是直径的四倍。而最大弯矩位于疏浚线下方的一小段距离处。前桩的最大弯矩约为尾桩的两倍，表明前桩承受的侧向土压力大于尾桩。(3)桩径、贯入深度和行距应保持在适宜的范围内；否则，DRBPW 可能会比预期更早地失败。细长比建议设置不大于30，贯入比不小于0.22。DRBPW 的最佳行间距是直径的四倍。(3)桩径、贯入深度和行距应保持在适宜的范围内；否则，DRBPW 可能会比预期更早地失败。细长比建议设置不大于30，贯入比不小于0.22。DRBPW 的最佳行间距是直径的四倍。(3)桩径、贯入深度和行距应保持在适宜的范围内；否则，DRBPW 可能会比预期更早地失败。细长比建议设置不大于30，贯入比不小于0.22。DRBPW 的最佳行间距是直径的四倍。