摘要
依托东莞某近接铁路桥梁软土深基坑工程,采用小应变土体硬化本构模型对设计支护方案进行有限元数值分析,并与现场监测数据进行对比。结果表明:在地连墙+混凝土支撑支护的基础上,邻近铁路桥墩地连墙外侧增设灌注桩形成门式刚架结构增大围护墙的刚度,环形混凝土支撑增设支撑板增大支撑刚度,能够有效提高基坑变形控制能力;基坑外2倍基坑深度范围内土体水平位移和竖向位移较大,对铁路桥墩变形影响较大;数值分析与现场监测铁路桥墩变形较为接近,其中顺桥向水平位移较小,最大值小于2.00 mm,而横桥向水平位移相对较大,最大值大于4.00 mm。
Relying on a deep foundation pit project in Dongguan near a railway bridge in soft soil,a small-strain soil hardening constitutive model was used to carry out a finite element numerical analysis of the designed support scheme and compare it with the field monitoring data.The result shows that,on the basis of the diaphragm wall+concrete support,the cast-in-place piles added outside the diaphragm wall of the adjacent railway pier form a portal frame structure that can increase the stiffness of the retaining wall;the support plates to the annular concrete support increases the support stiffness,which can effectively improve the deformation control ability of the foundation pit.There exists a big horizontal displacement and vertical displacement of the soil in the range of 2 times the depth of the foundation pit outside the foundation pit,which has a great influence on the deformation of the railway pier.The numerical analysis is close to the field monitoring of railway pier deformation,in which the horizontal displacement along the bridge is small,with the maximum value less than 2.00 mm,while the horizontal displacement across the bridge is relatively large,with the maximum value greater than 4.00 mm.
作者
涂启柱
孟长江
陈侃
TU Qizhu;MENG Changjiang;CHEN Kan(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China)
出处
《路基工程》
2025年第3期121-126,共6页
Subgrade Engineering
关键词
铁路桥梁
软土地区
深大基坑
组合支护
基坑监测
变形控制
经济性
安全性
railway bridge
soft soil area
deep and large foundation pits
combined support
foundation pit monitoring
deformation control
economy
safety
