摘要
在TBM输水隧洞衬砌管片拼装过程中,管片结构形式对于施工效率及难度的影响显著。作为一种新型管片,平行四边形管片能使衬砌达到自然错缝的效果,保证施工进度;但由于管片间接缝与隧洞轴线存在楔角,在拼装过程中可能承受较大压力,进而导致管片损坏。因此,考虑在单护盾模式下衬砌拼装过程中增加千斤顶推力,建立三维地层-衬砌数值模型,分析平行四边形管片的受力特点。研究发现,管片接缝附近应力集中,且应力值较大;接缝开度和压力与管片所承受千斤顶推力以及接缝位置有关。将接缝面分为P面和A面(P面为与其同一管片上千斤顶推力作用面夹角为锐角的接缝面,A面为夹角为钝角的接缝面)。对于同一接缝,当A面所属管片千斤顶压力与P面所属管片千斤顶压力之比不大时(P面承受千斤顶推力),接缝靠近千斤顶一端闭合,远离一端张开;当P面所属管片没有承受千斤顶推力、A面所属管片承受千斤顶推力时,接缝靠近千斤顶一端张开,远离一端闭合。
During the lining segment assembly of TBM tunnel for water transport,the structure of segments significantly influences the efficiency and difficulty of construction.As a new kind of lining segment,parallelogram segment can form staggered joint,then the construction progress can be improved.However,the wedge angle between joint surfaces of parallelogram segment and tunnel axis causes large pressure on the contact surface of segments during assembly,which may lead to damage of segment.In this study,by considering the driving force of jack under mono-protecting-shield mode,a three-dimensional lining model with rock mass is built to investigate the stress characteristics of parallelogram segment.It can be concluded that,stress concentration mainly exists near joints,where both the tensile stress and compressive stress are large;the opening and pressure of joint surfaces are related to the driving force of jack and the joint location.The joint surfaces are divided into surface P and surface A(the former is the joint surface where intersecting angle between the surface of the segment and the axis of the tunnel is acute,and the latter is the joint surface where the intersecting angle is obtuse).For one joint of two segments,when the ratio of driving force on one segment with surface A and on another segment with surface P is small or not very large,one end of the joint near the jack is closed,and another end of the joint splays to some extent.When there is no driving force on one segment with surface P,while driving force exists on another segment with surface A,the situation is opposite.
作者
苏凯
周小阳
杨风威
耿波
王美斋
SU Kai;ZHOU Xiaoyang;YANG Fengwei;GENG Bo;WANG Meizhai(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China;Yellow River Engineering Consulting Co.,Ltd.,Zhengzhou 450003,China)
出处
《武汉大学学报(工学版)》
CAS
CSCD
北大核心
2020年第6期471-482,共12页
Engineering Journal of Wuhan University
基金
国家自然科学基金资助项目(编号:51879207)。
关键词
平行四边形管片
TBM隧洞
管片衬砌
错缝拼装
千斤顶推力
parallelogram segment
TBM tunnel
segment lining
staggered joint erection
driving force of jack