铁路软岩隧道二次衬砌纵向裂缝成因分析  

Cause Analysis of Longitudinal Cracks of Secondary Lining in Railway Soft Rock Tunnel

作　　者：崔童 杜守继[1] 张武国 杨书宇 CUI Tong;DU Shouji;ZHANG Wuguo;YANG Shuyu(School of Naval Architecture,Ocean&Civil Engineering,Shanghai Jiaotong University,Shanghai 200240,China;China State Construction Railway Co.Ltd.,Beijing 100053,China)

机构地区：[1]上海交通大学船舶海洋与建筑工程学院,上海200240 [2]中建铁路建设有限公司,北京100053

出　　处：《铁道建筑》2018年第12期74-77,共4页Railway Engineering

摘　　要：准(格尔)朔(州)铁路哈镇隧道二次衬砌从内轨顶面至最大开挖跨度处出现连续纵向裂缝。根据现场勘测情况,采用室内试验和数值模拟方法,分析了二次衬砌产生裂缝的原因。开裂段围岩为砂岩夹泥岩条带,遇水易崩解软化,具有一定膨胀性,但仅围岩软化不足以使二次衬砌产生裂缝。围岩软化与膨胀共同作用时二次衬砌结构从内轨顶面至最大开挖跨度处出现拉应力,当膨胀压力超过一定值时二次衬砌结构所受拉应力将大于混凝土极限抗拉强度进而产生裂缝。这一结果与现场二次衬砌开裂情况一致。There are continuous longitudinal cracks from the top surface of inner rail to the maximum excavation span of secondary lining in Zhungeer-Shuozhou railway Hazhen tunnel.Based on f ield surveys,the causes of the cracks of secondary lining were analyzed by laboratory tests and numerical analysis method.The surveys and laboratory tests show that surrounding rock of cracked section is sandstone-mudstone strip,which is easy to disintegrate and soften in water and has certain expansibility,but the softening of surrounding rock is not enough to cause cracks of secondary lining.The tensile stress of the secondary lining structure appears from the top surface of the inner rail to the maximum excavation span when the softening and expansion of surrounding rock act together.The tensile stress of the secondary lining structure will be greater than the ultimate tensile strength of concrete and then cracks will occur when the expansion pressure exceeds a certain value,which is consistent with the cracks of secondary lining in the f ield.

关 键 词：铁路隧道 膨胀性岩土 试验研究 数值分析 二次衬砌 纵向裂缝 

分 类 号：U457.2[建筑科学—桥梁与隧道工程]