门架式双排桩受力位移特性分析

Analysis of Distribution Characteristics of Stress and Displacement of Portal Double-row Pile

研究目的:探求门架式双排桩桩身的内力位移分布特征及相应的设计施工技术。研究结论:(1)在桩排距较大的情况下,门架式双排桩的前排桩的桩顶位移明显小于单排悬臂桩和无连梁的双排桩;(2)门架式双排桩的前后排桩的最大弯矩和剪力比较接近,而且正负弯矩和剪力比较接近,表明连梁在协调前后排桩顶位移、桩身弯矩和剪力方面有明显的作用;(3)岩土层参数的选取是影响抗滑桩结构设计的一个重要因素;(4)门架式双排桩具有较大的侧向刚度,可以有效地限制支护结构的侧向变形;(5)对于膨胀土边坡,在实际施工中要做到及时开挖、及时防护,以减少施工对土体含水量和土体结构带来的扰动;(6)在实际应用中要采用数值计算与成功经验相结合的方式,以确保边坡稳定。

Research purposes： The analyses are made for the distribution characteristics of internal force of pile body of portal double -row pile and the corresponding design and construction technologies. Research conclusions： （ 1 ） The displacement in top of the front pile in portal double - row pile is obviously small than that of single -row pile and double- row pile without coupling beam, when the distance between two rows is big. （2） The max. moment and shearing force in the front pile are close to the back pile and the absolute value of positive moment and shearing force are close to the negative moment and shearing force. The coupling beam has an obvious effect on coordinating the moment and shearing force between the front pile and the back pile. （3） The parameters choice of the karst soil is an important influence factor on design of friction pile. （4） Portal double - row pile has lateral rigidity to effectively restrain the lateral deformation of exterior - protected construction. （5） To the side slope of expansive soil, the excavation and support should be conducted in time during engineering to reduce the disturbance of the water content and soil body by the engineering. （6） The numeral calculation should be adopted along with the experience for ensuring the stability of side slope.