地铁隧道钢纤维混凝土管片力学性能研究

A STUDY ON PERFORMANCE OF STEEL FIBER REINFORCED CONCRETE SEGMENT

为研究施工荷载作用下,管片局部抗压及环缝等薄弱部位的受力性能,对钢纤维混凝土管片的力学性能进行了三维数值模拟及现场试验,研究内容包括:(1)千斤顶作用下管片的局部抗压性能;(2)盾构直线推进及纠偏工况时管片的力学性能。研究结果表明,在最大施工荷载(900kN)作用下,管片局部抗压性能及手孔等应力集中部位均满足设计要求。同时,管片在施工荷载作用下没有裂缝产生,说明钢纤维混凝土管片抗裂性能较强。这也表明钢纤维的加入,大大提高了混凝土管片的力学性能,钢纤维混凝土管片用于地铁隧道工程是可行的。

The results of a numerical analysis and field measurement research of the performance of steel fiber reinforced concrete segments(SFRCS) in the shield tunnel of Shanghai Rail Transit Project Line 6 are presented.The objectives of this study are to investigate the mechanical behaviors of SFRCS during construction stage.The scope of the research involves:(1) the evaluation of the behaviors of the segment against the thrust forces of shield jacking;(2) the distribution of stress and strain of segment body;and(3) the distribution of stress and strain of circumferential joints of segments.According to the contacting condition between segment rings,the nonlinear finite element analyses were applied.At the same time,the field test was carried out using actual lining segments at one shield tunnel construction site.The results show that safety against the thrust forces of shield jacks,distribution of tension strain in segment body and joint meet the requirements of design and construction.No cracking has been found in segments under the construction loadings.This shows that the steel fibers provide the concrete segment an improved crack resistance.The performance of the segment has been enhanced by the addition of steel fibers,and SFRCS can be applied as a reasonable tunnel lining for subway tunnel.