基于土拱效应的遮帘桩合理桩间距分析

Analysis on Rational Spacing of Barrier Pile Based on Soil Arching Effect

遮帘桩的合理桩间距分析是遮帘式板桩码头设计中需要重点关心的问题之一。基于平行墙理论及最不利荷载情况下的朗肯主动土压力理论,推导出遮帘桩后水平土拱拱前自由区及拱后稳定区土压力表达式,并在此基础上,根据拱脚水平静力平衡条件及三角形受压区强度条件得到了遮帘桩合理桩间距的计算式。结果表明:与已有土拱稳定分析方法相比,由于考虑了拱前自由区土压力的支撑作用,形成稳定土拱所需宽度有所增大,遮帘桩的合理桩间距因此也可以有所放大,并根据一算例进行了验证。

Rational spacing of barrier pile is an important issue for the design of all-covered type of sheet-pile wharf. Based on parallel walls theory and Rankine＇s active earth pressure theory in the worst condition of loading,an expression of earth pressure in the zone before and after the soil arch was deduced in this paper. On the basis of this,a calculation formula for rational spacing of barrier pile in association with the static equilibrium equation and shear strength conditions of the triangle compression zone was obtained. The result shows that,in the new formula,support of earth pressure in the free zone before the soil arch is taken into consideration,the width needed to form soil arch of the new formula is bigger than that of the existing calculation method. In light of this,the rational spacing of barrier pile can be slightly increased and the result is verified by a case study.