嵌岩深度和加固范围对深厚软土桩基托梁结构的性能影响  

Influence of Rock-socketed Depth and Reinforcement Range on Performance of Pile Foundation Joist Structure in Deep Soft Soil

作　　者：李永奎 杨贵勇[1] 徐宇 LI Yongkui;YANG Guiyong;XU Yu(Chengdu Survey,Design and Research Institute Co.,Ltd.of CREEC,Chengdu 610081,China)

机构地区：[1]中铁二院成都勘察设计研究院有限责任公司,成都610081

出　　处：《路基工程》2024年第1期144-149,共6页Subgrade Engineering

摘　　要：以某新建铁路工程为例,基于有限元软件,以钻孔灌注桩桩基嵌入基岩深度(5种嵌岩深度)和桩前旋喷桩加固区范围大小(6种不同排数旋喷桩加固范围)作为控制变量,研究桩基的力学特性和路基面沉降。结果表明:灌注桩桩基的最大水平应力出现在土石界面附近,增加桩基的嵌岩深度和增加桩前旋喷桩排数都可有效降低桩基的水平变形和路基面沉降,桩基嵌岩深度为1D(D为灌注桩直径)或桩前旋喷桩为3排时,变化速率出现由快到慢的拐点。选择桩基长度为16m、桩前旋喷桩为3排的加固方式,具有较好的经济性。Taking a newly-built railway project as an example,based on finite element software,the depth of cast-in-place bored pile embedded in bedrock(5 pieces of depth data)and the size of reinforcement range by rotary jet grouting pile in the front(6 pieces of row numbers for reinforcement)were taken as the control variables to study the mechanical properties of the pile foundation and the settlement of the subgrade surface.The results show that,the maximum horizontal stress of the cast-in-place pile foundation appears near the soil-rock interface,and increasing the rock-socketed depth of pile foundation and the row number of jet grouting pile in the front can effectively reduce the horizontal deformation of the pile foundation and the settlement of the subgrade surface.When the rock-socketed depth of the pile foundation is 1D(D is the diameter of cast-in-place pile)or the row number of jet grouting pile in the front is 3,the change rate appears an inflection point from fast to slow.The pile foundation length is 16 m and the jet grouting pile in the front is 3 rows,which has good economy.

关 键 词：深厚软土 桩基托梁结构 嵌岩深度 位移监测 路基沉降 经济性 

分 类 号：U418.55[交通运输工程—道路与铁道工程]