PBA车站导洞双向开挖方案比选  

The Comparison and Selection of Schemes on Pilot Tunnels' Bidirectional Excavation in Metro Stations Constructed by PBA Method

作　　者：单仁亮[1] 黄博[1] 李润军[1,2] 李兆龙[1] 陈慧娴[1] 

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083 [2]北京城建设计发展集团股份有限公司,北京100088

出　　处：《沈阳建筑大学学报（自然科学版）》2016年第2期200-208,共9页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金项目(51134025);中央高校基本科研业务费专项资金项目(2010YL09)

摘　　要：目的研究采用PBA工法暗挖地铁车站时最优的导洞双向开挖方案.方法通过数值模拟的手段,模拟了横通道内小导洞双向开挖的过程,对比研究不同的导洞间开挖错距和不同的导洞开挖顺序对横通道处地表沉降的影响.结果随着开挖错距的增加,地表的最大沉降值在增加,而反弯点距离在逐渐减少,折中考虑15 m是最为合理的导洞开挖错距;横通道内导洞开挖如果存在紧随相邻且相对导洞的情况,会使得横通道处地表沉降值增加,而边导洞支护体系形成越早,会使得反弯点距离减小.结论在多种开挖顺序中,方案(2,4)-(5,7)-(1,3)-(6,8)引起的地表沉降值最小,反弯点距离较小,开挖顺序合理,有利于组织施工,且每一步开挖引起的地表沉降均匀,是最为合理的开挖顺序.The best scheme on pilot tunnels＇ bidirectional excavation in metro stations constructed by PBA method is studied in this paper. The processes of pilot tunnels＇ bidirectional excavation in cross passage are simulated through numerical simulation. The influences that alternate distance and sequence of pilot tunnels＇ excavation have on surface settlement are studied by analyzing simulation results. The results show： with the alternate distance increasing,the maximum settlement is increasing and the inflection point distance is decreasing gradually. Comprehensive consideration,15 m is the best alternate distance; the surface settlement above cross passage will increase,when a pilot tunnel is excavated followa both adjacent and opposite one; the earlier supports of side pilottunnels finish,the smaller the inflection point distance become. Among the several excavation sequences,（ 2,4）-（ 5,7）-（ 1,3）-（ 6,8） is the best scheme because it causes the minimum surface settlement,it has relatively smaller inflection point distance,settlement is uniform during the construction,and it is convenient for organizing construction.

关 键 词：PBA工法 数值模拟 方案比选 双向开挖 开挖错距 开挖顺序 地表沉降 

分 类 号：TU37[建筑科学—结构工程] U231.4[交通运输工程—道路与铁道工程]