预留土和桩锚结构联合支护下基坑的力学性状  

Mechanical properties of foundation pit supported by reserved soil and pile-anchor structure

作　　者：张文举 朱浩延 刘敏 朱宏伟[2] ZHANG Wenju;ZHU Haoyan;LIU Min;ZHU Hongwei(China Municipal Engineering Southwest Design and Research Institute Co.,Ltd.,Chengdu 610031,China;School of Environment and Resource,Southwest Science and Technology University,Mianyang 621010,China)

机构地区：[1]中国市政工程西南设计研究总院有限公司,四川成都610031 [2]西南科技大学环境与资源学院,四川绵阳621010

出　　处：《四川建筑科学研究》2024年第1期60-69,81,共11页Sichuan Building Science

基　　金：国家自然科学基金项目(41472294)。

摘　　要：桩锚结构在基坑支护中应用广泛,但在其设计计算时往往以经验为准,存在一定的盲目性和不确定性。依托在建工程,通过数值模拟分析了预留土作用下桩锚结构设计参数的变化对基坑力学性状的影响。结果表明:基坑支护桩的最大水平位移发生在桩顶,桩底的位移非常小;基坑周边地表沉降呈槽形分布,最大沉降在距离基坑边缘5 m左右的位置;弯矩分布曲线沿桩身有2个峰值点,峰值点大概位于桩顶以下3 m和10 m处;当锚索锚固角为15°时,桩身水平位移和弯矩、基坑周边地表沉降都比较小;锚索锚固点距离桩顶越远,桩身水平位移、基坑周边地表沉降越大;当预应力大于200 kN后,桩身水平位移和弯矩、基坑周边地表沉降几乎不再减小。Pile-anchor structure is widely used in foundation pit support,but the design and calculation are always subject to experience,which has certain blindness and uncertainty.The influence of design parameters of pile-anchor structure on mechanical properties of foundation pit under the action of reserved soil was analyzed by numerical simulation.The results show that the maximum horizontal displacement of foundation pit supporting pile occurs at the top of pile,while the displacement of pile bottom is very small.The surface settlement around the foundation pit is distributed in groove shape,and the maximum settlement is about 5 m away from the edge of the foundation pit.The bending moment distribution curve has two peak points along the pile body,and the peak points are about 3 m and 10 m away from the pile top.When the anchoring angle of anchor cable is 15°,the horizontal displacement and bending moment of supporting pile and the surface settlement around the foundation pit are relatively small.The farther the anchorage point is from the pile top,the greater the horizontal displacement of foundation pit supporting pile and the surrounding surface settlement.When the prestress is greater than 200 kN,the horizontal displacement and bending moment of piles and surrounding surface settlement basically do not decrease.

关 键 词：基坑 桩锚结构 预留土 力学性状 数值模拟 

分 类 号：TU473.1[建筑科学—结构工程] TV551.4[建筑科学—土工工程]