上软下硬地层盾构施工多源沉降数据演化规律  

Multi-source Settlements Evolution Mechanisms Induced by Tunnel Shielding in Upper-soft and Lower-hard Strata

作　　者：李炜明[1] 任虹 孙义涛 沙梦宜 张燕舞 石旭东[2] LI Weiming;REN Hong;SUN Yitao;SHA Mengyi;ZHANG Yanwu;SHI Xudong(Wuhan Polytechnic University,Hubei 430023,China;China Railway 19th Bureau Group Co.Ltd,Beijing 100176,China)

机构地区：[1]武汉轻工大学,武汉430023 [2]中铁十九局集团有限公司,北京100176

出　　处：《铁道工程学报》2020年第9期78-84,共7页Journal of Railway Engineering Society

基　　金：国家留学基金项目(201508420221);桥梁工程安全控制技术与装备湖南省工程技术研究中心(长沙理工大学)开放基金资助项目(12KC01);湖北省高等学校省级教学研究项目(2017359)。

摘　　要：研究目的:上软下硬地层为城市地铁施工中的一种特殊地质,在这种地层中,盾构施工的条件与已有经验公式的假设条件存在差异,并有可能对衬砌、箱涵与管线结构造成工程风险。因此,有必要基于实际工程的监测数据进行针对性的研究。研究结论:本文基于长期施工监测数据的分析,对于某城市地铁上软下硬地层的盾构施工,有如下结论:(1)本区段单线盾构施工时,横向沉降槽形状会受到施工工况的影响,基本符合Peck曲线,最大沉降值大致位于开挖隧道中心线处,产生了较为显著的地表沉降,最大值接近30 mm;(2)本区段盾构施工地表沉降纵断面沉降曲线形状分为4个阶段,掌子面通过时出现较大日沉降;(3)本区段上软下硬地层盾构施工过程中,因为隧道衬砌、箱涵、热力管线自身具有一定刚度,盾构施工时结构沉降会小于土体沉降;衬砌沉降幅值在[-1,+2]mm区间,箱涵、热力管线沉降幅值在[-12,+1]mm区间;(4)本研究成果可为类似上软下硬地层地铁盾构施工设计与施工提供参考。Research purposes: The upper-soft and lower-hard strata are a special geological condition in the construction of urban subways. The soil settlement during shield construction in this stratum is different from the assumptions of the existing empirical formulas,which may be the engineering risk to the structure of the lining,the box culvert,and the pipe line. It is necessary to investigate the settlement based on the engineering monitoring data.Research conclusions: Based on the analysis of long-term construction monitoring data,this paper has the following conclusions:( 1) The settlement curve of the cross-section is generally consistent with Peck curve while shielding single tunnel in upper-soft and lower-hard strata. The curve shape may be affected by the construction factors. The maximum settlement is close to the centre line of the tunnel,and the value is about 30 mm.( 2) The vertical section is divided into 4 parts,and the settlement is significant while the shielding face going through the upper-soft and lower-hard strata.( 3) The settlements in this section of the structures are always less than the settlement of the soil,because the stiffness of the tunnel lining,box culvert and pipe line. The settlement of the tunnel lining is in the section of [-1,+ 2]mm,and the settlement of the box culvert and the pipe line is the section of [-12,+ 1]mm.( 4) The research result can be helpful for the design and construction of subway shield in similar upper soft lower hard stratum.

关 键 词：盾构施工 上软下硬地层 土体沉降 结构沉降 监测数据 

分 类 号：U455[建筑科学—桥梁与隧道工程]