土体冻胀对桩锚支护结构影响试验研究  

Experimental Study on the Effect of Soil Frost Heave on Pile-anchor Supporting Structure

作　　者：高欣亚 李元勋 石冬梅 李双好 向田 Gao Xinya;Li Yuanxun;Shi Dongmei;Li Shuanghao;Xiang Tian(School of Civil Engineering Qinghai University,Xining 810016,P.R.China)

机构地区：[1]青海大学土木工程学院,西宁810016

出　　处：《地下空间与工程学报》2021年第3期692-697,共6页Chinese Journal of Underground Space and Engineering

基　　金：青海省科技厅项目(2018-ZJ-933Q;2018-ZJ-T01);教育部“春晖计划”(QDCH2018002)。

摘　　要：在我国西北季节性冻土地区,冬季土体冻胀对基坑安全危害不容忽视。为探究土体冻胀与桩锚支护结构间的相互作用,进行桩锚支护结构基坑冬季室外试验。通过研究冻胀作用下桩锚支护结构内力与桩后土压力的变化规律,得出以下结论:浅层桩侧土压力易受温度与土体含水率等多种因素影响产生突变;支护桩上部内力随冻胀次数增加而增大,锚杆能够减弱土体冻胀对桩身内力的影响;温度降低可使桩身上部弯矩增幅变大;锚杆自由段应力大于锚固段,且锚固段应力易受冻胀作用影响产生增长。所得结论可为桩锚支护结构在季冻区基坑工程中的应用提供参考。In the northwest seasonal frozen area,the danger of soil frost heaving to the safety of foundation pits in winter can not be ignored.In order to explore the interaction between soil frost heave and pile-anchor supporting structure,winter outdoor tests of the foundation pit of the pile-anchor supporting structure were carried out.The variation of internal force of pile-anchor supporting structure and soil pressure behind pile under frost heave was studied.Conclusions are drawn as follows:The soil pressure on the side of the shallow pile is susceptible to abrupt changes due to various factors.The internal force of the upper part of the supporting pile increases as the number of frost heave increases,and the anchor rod can weaken the influence of soil frost heave on pile internal force.Lower temperature can increase the bending moment increase of the upper part of the pile.The stress in the free section of the anchor rod is greater than that in the anchor section,and the gap between the stress of the free section of the shallow soil anchor and the anchor section is large.The conclusions obtained can provide a reference for the application of pile-anchor supporting structure in foundation pit engineering in seasonal frozen areas.

关 键 词：土体冻胀 桩锚支护结构 室外实验 桩侧土压力 

分 类 号：TU445[建筑科学—岩土工程]