厦门淤泥地层大跨度浅埋暗挖地下通道三维变形分析

3-D Deformation Analysis of Xiamen Long-span Underground Passage Embedded in Silt and Built by Shallow Mining Excavation

以厦门市典型淤泥地层修建大跨度浅埋暗挖城市地下通道为工程背景,借助abaqus有限元软件分析市中心某地下通道的三维变形效应和特征,对不同工况下的预加固效果做出评价。分析结果表明,在地下通道下承的大体积淤泥中采用高压旋喷桩斜向加固地层,在开挖区域及其两侧采用高压旋喷桩水平向加固地层,并结合长管棚超前预加固可以很好地控制基础沉降和地表沉陷,若进一步用易切削玻璃纤维锚杆对"待挖核心体"进行纵向加固,则可以更好地控制土体变形,降低施工对周围环境、建筑物以及地下管线的影响。

With typical Ximen long-span underground passages embedded in silt and built by shallow mining excavation as the project background, 3-D deformation characteristics of a passage in the city center was analysed by means of FE software absqus to evaluate the pre-reinforcement effect under different working conditions. Results indicated, obligue-oriented reinforcement of the passage underlying silt mass by adopting pressurized rotary jet grouting, horizontal reinforcement of the excavated zone and two sides of it by adopting pressurized jet grouting incorporating advance reinforcement by long pipe-roofing can effectively control the settlements of foundation and surface subsidence. If longitudinal reinforcement of the core earth mass to be excavated is performed by adopting easy-cutting glass fiber bolts, deformation of soil mass can be further controlled and the influence of construction on environment, buildings and underground facilities can be alleviated.