基于混凝土支撑轴力伺服技术的深基坑开挖数值模拟与监测分析

文章以上海市谈家桥路旧住房拆除重建工程基坑为研究案例,利用Midas GTX NX软件构建3D模型,对比分析了有无混凝土支撑轴力伺服两种情况下的基坑开挖数值模拟结果,并结合现场实测数据进行了深入研究。研究结果显示,采用混凝土支撑轴力伺服技术能够显著减少基坑变形,满足了基坑微变形控制要求,对敏感区周边环境保护具有重要作用;基于实测数据修正的基坑开挖模型可精确模拟单一施工要素变化后的变形情况,为基坑变形机理研究和预测提供了重要参考。This article takes the foundation pit of the old housing demolition and reconstruction project on Tanjiaqiao Road in Shanghai as a research case, constructs a 3D model using Midas GTX NX software, compares and analyzes the numerical simulation results of foundation pit excavation under two conditions: with and without concrete support axial force servo, and conducts in-depth research based on on-site measured data. The research results show that the use of concrete support axial force servo technology can significantly reduce the deformation of foundation pits, meet the requirements of micro deformation control of foundation pits, and play an important role in protecting the surrounding environment of sensitive areas;The excavation model of foundation pits modified based on measured data can accurately simulate the deformation situation after a single construction element changes, providing an important reference for the research and prediction of foundation pit deformation mechanisms.

贴壁混凝土板高度对岩锚梁稳定影响

以金川水电站为例,利用Midas GTX NX有限元计算软件,计算分析贴壁混凝土高度对岩锚梁锚杆轴力、岩锚梁应力、应变以及贴壁混凝土内力的影响。结果表明,增加贴壁混凝土板高度导致:(1)岩锚梁受拉锚杆、受压锚杆拉应力降低,岩台面附近受拉锚杆拉应力增加;(2)岩锚梁压应力降低,第一主拉应力和纵向正拉应力降低,第二主拉应力、第三主拉应力增加;(3)竖向向上隆起变形以及水平向向上游方向的变形减小,贴壁混凝土板高度的增加使得岩锚梁各处变形更为均匀;(4)贴壁板下端局部区域拉应力急剧增加,最大主拉应力和纵向拉应值大于混凝土抗拉强度标准值,可以通过配置钢筋承担拉应力。