土质斜坡坡顶沉桩对指定滑动面安全系数影响分析

发布时间：2018-03-27 09:04

本文选题：沉桩　切入点：球孔扩张　出处：《岩土工程学报》2016年09期

【摘要】：利用边坡稳定性计算方法,基于球孔弹塑性扩张理论,研究了沉桩力、桩端塑性区以及桩体抗滑作用对沉桩过程中滑动面安全系数的影响。通过算例,对沉桩全过程中滑动面安全系数变化进行了研究,并对桩径,边坡角度以及沉桩距边坡顶点距离对沉桩过程中边坡滑动面安全系数变化的影响进行了分析。结果表明:沉桩力及桩端塑性区对滑动面稳定性产生不利影响,使安全系数降低;当桩体穿过滑动面之后,桩体起到抗滑作用,显著提高滑动面安全系数。桩径越大,沉桩前期安全系数下降速度越快,但桩端穿过滑动面后安全系数提升也更加显著;边坡角度越大,沉桩后边坡安全系数越小;沉桩离边坡顶点越远,在沉桩前期由于沉桩力导致的安全系数下降速度越慢,塑性区对安全系数的影响也逐渐减缓,当沉桩远离边坡顶点距离达到一定值后,沉桩将不再对滑动面稳定性产生影响。分析结果对邻近边坡沉桩的设计和施工具有一定的实用价值。
[Abstract]:Based on the elastic-plastic expansion theory of spherical holes, the influence of pile driving force, pile tip plastic zone and pile body anti-sliding on the safety factor of sliding surface in the process of piling is studied by using the slope stability calculation method. The variation of safety factor of sliding surface in the whole process of piling is studied, and the diameter of pile is also studied. The influence of slope angle and distance from the pile to the top of the slope on the safety factor of the slope sliding surface is analyzed. The results show that the piling force and the plastic zone at the end of the pile have a negative effect on the stability of the sliding surface, which reduces the safety factor. When the pile body passes through the sliding surface, the pile body plays a role of anti-sliding, and the safety factor of the sliding surface is improved significantly. The larger the diameter of the pile, the faster the safety factor of the pile sinking is decreased, but the more significant the safety factor is after the pile end passes through the sliding surface. The bigger the slope angle is, the smaller the slope safety factor is after piling, and the farther the piling is from the top of the slope, the slower the safety factor decreases due to piling force in the early period of piling, and the influence of plastic zone on safety factor is gradually reduced. When the piling distance from the top of the slope reaches a certain value, the stability of the sliding surface will no longer be affected by the piling. The results of the analysis have certain practical value for the design and construction of the pile driving on the adjacent slope.
【作者单位】：上海理工大学土木工程系;
【基金】：国家自然科学基金青年基金项目(51208301)
【分类号】：TU473.1

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