复杂城市环境下铁路车站基坑施工引起邻近隧道水平变形的控制技术分析

Analysis of Control Techniques for Horizontal Deformation of Adjacent Tunnels Induced by Construction of Railway Station Excavations in Complex Urban Environments

坑内开挖卸载会引发坑底土体向上隆起变形、基坑围护结构变形以及基坑周边土层的移动。在复杂城市环境下进行基坑开挖,会对基坑相邻的地下管道、建筑物基础、隧道及其他地下设施产生影响。随着铁路车站基坑场地与位移敏感类建筑物的距离持续变小,变形控制尺度从cm级向mm级转变,变形控制的难度逐渐增大。通过对基坑开挖引起相邻地下结构变形控制进行系统性研究,可以将变形控制分为针对基坑源头的变形控制和针对位移控制目标的变形控制。本文详细阐述了两类控制技术的基本原理和应用局限性,并围绕基坑开挖前预注浆、囊式注浆装置等方面,重点提出了注浆主动控制技术的创新研究方向。

Excavation unloading within a pit triggers upward heave deformation of soil at the pit bottom,deformation of the pit’s retaining structure,and displacement of surrounding soil layers.Excavation of foundation pit in complex urban environments can impact adjacent underground pipelines,building foundations,tunnels,and other subterranean facilities.As the distance between railway station excavation sites and displacement-sensitive structures continues to shrink,the control scale shifts from centimeters to millimeters,increasing the difficulty of deformation control.Through systematic research on deformation control induced by excavation on neighboring underground structures,deformation control can be categorized into two types:source-based control targeting the excavation itself and target-based control aimed at displacement-sensitive objectives.This paper reviewed the fundamental principles and application limitations of these two control techniques,and highlighted innovative research directions for active grouting control technology,specifically emphasizing aspects such as pre-excavation grouting and inflatable grouting devices.