摘要
针对目前置换硬壳层法提高软土中桩基水平承载力的定量计算研究不足的问题.推求根据地基土抗剪强度指标计算其水平抗力参数的公式,基于线弹性理论,对成层软土地基采用置换硬壳层法处理后桩基水平承载力提高影响进行深入研究,利用微分方程幂级数解法推求成层土地基中桩基水平承载力的解析计算式,分别在桩顶自由、嵌固条件下,讨论分析置换硬壳层厚度、置换硬壳层抗剪强度指标等对软土中桩基水平承载力提高的影响关系,认为硬壳层土内摩擦角越大(水平抗力系数越大)、厚度越厚,则桩基水平承载力提高越大、桩顶水平变位越小。最后依托于浙江省某桩基工程案例,通过对2种硬壳层换填土的计算讨论,认为硬壳层置换厚度在2〜3 m时(桩径0.8 m)桩基水平承载力提高基本达到峰值,此时桩基水平承载力提高7〜15倍,且桩顶水平位移也减小85%〜95%,桩身最大弯矩也减小一半左右,对类似工程应用提供参考价值。
To calculate the pile foundation's horizontal bearing capacity by the replacement hard shell method,a formula was established for calculating the horizontal resistance parameters according to the shear strength index of the foundation soil.The layered soft after the foundation is treated with the replacement hard shell method.The influence of the horizontal bearing capacity of the pile is revealed by the analytical calculation formula for the horizontal bearing capacity of the pile is derived.Under the conditions of embeddedness,the influence of the thickness and the shear strength index of the replacement hard shell layer on the increase of the horizontal bearing capacity of the pile was discussed and analyzed.The results revealed that the greater the internal friction angle of the hard shell soil and the thicker the thickness,and the greater the increase in the horizontal bearing capacity of the pile and the smaller the horizontal displacement of the pile top.Finally,a case of a pile foundation project in Zhejiang Province was studied,it indicated when the replacement thickness of the hard shell layer is 2-3 m(pile diameter 0.8 m),the increase in bearing capacity basically reaches the maximum value and the horizontal bearing capacity of the pile foundation is increased by 7 to 15 times.However,the horizontal displacement of the pile top is reduced by 85%to 95%,as well as the maximum bending moment of the pile body is reduced by about half.This study could provide a reference tool for similar engineering applications.
作者
黄朝煊
李俊杰
HUANG Chaoxuan;LI Junjie(Zhejiang Design Institute of Water Conservancy and Hydroelectric Power, Hangzhou,Zhejiang 310002,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2021年第S02期3472-3482,共11页
Chinese Journal of Rock Mechanics and Engineering
基金
浙江省基础公益研究计划项目(LGF18E090004)
浙江省水利厅科技计划项目(RC1701)
浙江省水利水电勘测设计院科标业项目资助(B1803)
关键词
基础工程
软土地基
桩基水平承载力
地基土水平抗力
硬壳层
抗剪强度指标
解析解
foundation engineering
soft soil foundation
horizontal bearing capacity of pile foundation
horizontal resistance of foundation soil
hard shell layer
shear strength index
analytical solution
