SMW工法桩紧邻建筑物跳仓施工优化数值分析

Numerical Analysis on Optimization of Skip Construction of SMW Pile Adjacent to Buildings

SMW工法桩因其施工速度快、堵水性能好的优势,在软土基坑工程中广为应用,但传统SMW工法的连续施工在水泥土硬化前期,易诱发紧邻建筑物地层的扰动,周边建筑物的安全性难以得到保障。以南昌地铁3号线六眼井站富水软土地层深基坑工程为例,基于数值方法建立了SMW工法桩按连续施工和跳仓施工两种计算工况,对比分析不同工况下SMW工法桩施工引起的周边地层力学响应,通过建立不同施工长度和跳仓间距下的数值模型,结合现场施工条件和施工效率的要求,阐明了紧邻建筑物SMW工法桩跳仓施工的可行性与优越性。根据计算分析结合工法桩实际施工要求,确定采用跳仓1幅距离施工的方案。在保证安全的前提下,减少了对周边地层的扰动影响,提高了施工效率。

The SMW columns are widely applied in strengthening the urban soft soils because of its advantages of fast installation and good groundwater seepage blocking performance.This paper presents a deep excavation project case history in the saturated soft soils with adjacent old building in Liuyanjing station of Nanchang Metro Line 3.The sequential installation of the conventional SMW columns is easily to induce the disturbance of adjacent building stratum in the early stage of cementsoil hardening.Therefore,the safety of the surrounding buildings cannot be warranted.Two analytical conditions of SMW column sequential and skip installations are established based on the numerical method,and the mechanical responses of the surrounding strata caused by the SMW column installation under different working conditions are compared and analyzed.By setting up the numerical model of different installation length and skip distance,combining the requirement of the installation condition and the efficiency,this paper presents the feasibility and advantage of column skip installation by SMW method in adjacent buildings.According to the analysis combined with the actual installation requirements of the construction method,the construction method of skip one distance is determined.On the conditions of ensuring safety,the disturbance to the surrounding strata is minimized and the installation efficiency is improved.