梯形抗滑桩截面侧角对土拱效应的影响

Influence of the Side Angle of Trapezoidal Anti-slide Pile on Soil Arching

为研究梯形抗滑桩截面侧角对土拱效应的影响,从材料力学与静力学知识入手,首先以拱轴线轴向受压模型推导了合理的桩截面侧角的计算方法,表明梯形截面抗滑桩较于矩形截面抗滑桩更易形成土拱效应;其次通过work-bench建立了土质边坡与梯形截面抗滑桩的三维模型并进行网格划分,运用FLAC3D有限差模拟软件进行数值模拟,通过接触面语句,建立桩土接触面,对桩土接触面的位移变化进行捕捉,结合在特征水平截面z=23上的应力云图、位移云图以及桩间中轴线上位移监测点的位移变化,综合分析梯形截面抗滑桩的桩截面侧角θ的取值对于土拱效应的影响;最后对理论推导结果与数值模拟结果进行了拟合。结果表明:以拱轴线的轴向受压模型理论,突出轴向大主应力的影响,得出当梯形截面抗滑桩抗滑反力最大时,截面侧角反算办法取值为2θ+arctanη取■π/2,θ∈(0,90°);得出了合理的桩截面侧角的取值范围,证明了梯形桩截面侧角在此范围下,能充分发挥桩正面与桩侧面两部分的受力性能,促使双拱协同传力机制的产生。

In order to study the influence of soil arch effect from the angle measurement of the trapezoid anti-slide section,with the knowledge of materials mechanics and statics,Firstly,a reasonable calculation method of pile cross-section side angle was derived base on the axial compression model of arch axis,which indicated that the trapezoid anti-slide section was more easily than the rectangular section anti-slide pile to form the soil arch effect.Secondly,the three-dimensional model of sliding resistance of soil slope and trapezoidal cross section anti-skid was established by work-bench and carry on network partitioning,The FLAC 3D finite difference simulation software was used to figure simulation,by the contact surface,building the pile-soil contact surface,catching the movement change of the pile-soil contact surface,combining the movement change of the movement monitoring points on axle wire of the contact surface of pile z=23,comprehensive analysis the effect of the value of cross section side angleθof the trapezoidal cross section anti-slide pile for the geotechnical effects.Finally,the result of the theoretical derivation and numerical simulation were fit and combined.The results show that,based on simulation theory of the axial compression of arch axis,the influence of axial large main stress is outstanding,and it is concluded that when the anti-slide reaction force of trapezoidal section anti-slide pile is the maximum,the value of cross-section side angle back calculation method is.The reasonable range of pile cross-section side angle is obtained.It is proved that the lateral angle of trapezoidal pile section which is in this range can give full play of the mechanical properties of the front and side of the pile,to promote the engendering of the transmission mechanism with dual synergy.