大空间建筑环形点式重载作用下深废矿坑岩壁变形稳定性数值分析

Numerical investigation on stability of disused deep mining pit under annular heavy point loading from large space structure

近年来,大城市工程建设急速发展,土地资源愈发紧张,一些矿产资源型城市中出现了利用废弃天然矿坑进行地下空间开发的改造项目。以长沙湘江欢乐城深废矿坑改造开发工程项目为背景,针对矿坑边坡稳定性以及受建筑结构点式荷载作用下的岩壁与基础协同作用问题,利用数值分析手段建立三维岩壁建筑结构相互作用模型。研究岩壁在环形点式受荷条件下的表现,并探究遭遇突发性岩壁变形及承载状态变化后岩壁与结构的稳定性变化情况。结果表明:在天然状况下,废弃矿坑的开采高边坡基本处于稳定状态;而施工扰动和建筑荷载造成的应力变形仅发生于岩壁表面,未达岩体深部;岩壁由于突发灾害产生的局部大变形会严重危及支承其上的基础和结构安全;而在合理的建筑物环形点式基础设计布置情况下,基础结构的偶然失效不会影响岩壁和建筑物的稳定性。

In recent years,with the rapid development of urban construction,land resources are increasingly tense.In some mineral resource-based cities,the transformation projects of underground space development using abandoned natural mining pits have appeared.This paper focuses on the rock slope stability problem with reference to a deep mining pit renovation project in Changsha.Aiming at the stability of mine pit slope and the synergistic action of rock wall and foundation under the point load of building structure,a three-dimensional interaction model of rock wall-building structure has been established by numerical analysis method.The behavior of rock wall under circular point loading has been studied.And the changes of stability of rock wall and structure after sudden deformation of rock wall and change of bearing condition have been also investigated.The results show that the mining high slope of abandoned pit is basically in a stable state under natural condition;the stress and deformation caused by construction disturbance and construction load only occur on the surface of rock wall,not reach the depth of rock mass;local large deformation of rock wall due to paroxysmal failure will seriously endanger the safety of the mining pit foundation and its overlying structures.The occasional failure of the foundation structure will not affect the stability of the rock wall and the building under the reasonable design and layout of the circular point foundation.