摘要
以中冶·德贤府邸的13栋高层建筑基坑为对象,采用平面应变的数值分析方法,研究了在土钉和预应力锚索的组合支护结构形势下基坑的变形规律和支护结构受力特征,并通过与现场监测数据的对比分析,论证了支护结构对基坑开挖变形控制的有效性。研究结果表明:土钉和预应力锚索的支护结构形式能有效限制基坑的变形,使得基坑壁水平变形仅为无支护时的45%,有效保障了基坑施工安全;预应力锚索是基坑开挖过程中的主要承载结构,最大内力约为97 kN,在其作用下基坑壁的变形以预应力锚索为界分为两个区域,即变形量值较小且呈现出快速收敛的上部变形区域和变形量值相对较大、收敛缓慢的下部区域;在预应力锚索作用下,基坑壁上部水平变形量值仅为下部的25~50%。
This paper presents a case history of the deep excavation support for a 13 stories high building.The deformation and stress in the supporting structure using plane strain numerical analysis method is utilized to simulate soil nail wall with prestressed ground anchor for deep excavation.The numerical analysis results are compared with the construction monitoring data and the feasibility of the supporting structure is validated.The results indicate that,the deformation of excavated area can be effectively constrained by the support structure combining the soil nails and pre-stressed ground anchors.The horizontal deformation of the surface near the edge of the excavation is 45%of that when the excavated area having no support.This effectively ensures the safety of excavated area.The pre-stressed ground anchor is the major loading carrying structure when the foundation is excavated,and the maximum internal stress is about 97 kN.Under the effect of the pre-stressed ground anchor,the excavated surface can be divided by two areas,in the upper area,the deformation is relatively small,and the deformation is fast converged,whereas in the lower area,the deformation is relatively large,and the deformation is slowly converged.Under the effect of the pre-stressed ground anchor,the horizontal deformation of the excavated surface in the upper area is merely 25~50%of that of the lower area.
作者
解宝金
XIE Baojin(China MCC17 Group Co.Ltd.,Ma'anshan 243000)
出处
《土工基础》
2023年第6期971-974,共4页
Soil Engineering and Foundation
关键词
基坑
变形控制
土钉
预应力锚索
数值模拟
Deep Excavation
Deformation Control
Soil Nails
Prestressed Ground Anchor
Numerical Simulation
