摘要
衬砌裂损是隧道病害中常见的问题,也是严重威胁结构安全的一个重要因素。除了温度变化、水害、衬砌本身的强度和厚度不足以及混凝土耐久性降低外,隧道围岩压力变化是衬砌产生裂损直至破坏的主要原因。文章针对铁路运营隧道病害的检测结果,对衬砌背后空洞进行平面弹塑性计算分析,得出不同位置、不同大小的空洞以及空洞群对结构各截面安全系数影响的系统认识,明确提出衬砌结构与围岩结合的不紧密性是恶化衬砌受力条件、造成围岩进一步松动、进而造成衬砌裂损的一个重要原因。文章还对直墙式及曲墙式衬砌所受到的不同影响进行了比较分析。认为曲墙式衬砌拱部结构能较好地将内力传递给边墙,由边墙部分承受较大的水平抗力,优化了整体结构的受力,从而降低背后空洞对衬砌结构的影响。通过对计算结果的系统分析和研究,合理解释了实际检测中的问题。
The lining's crack is an ordinary problem in tunnel disaster as well as an important factor of influencing structure's safety.The variation of surrounding rock pressure is a major cause which makes the lining cracked besides the temperature change,the water disaster,the lacking strenght,the deficient thickness and the reducing of concrete wear.The paper calculates and analyzes the cavities behind the lining with 2D elasto-plastic FEM method based on inspection results of the railway tunnel's disaster.The analysis educes a systematic cognition on the effect to lining's safety factor by different positions,different size cavities and cavity groups,and put forward sharply that the gapping between lining and surrounding rock is the important cause which worsens the lining's stress and looses the surrounding rock.The paper also compares the different effect on the straight-wall lining and the bent-wall lining,and considers that the bent-wall lining can transfer the load to the sidewall better,thereby reduces the influence of the back cavities.And then,this paper gives reasonable explanations to problems of the inspection.
出处
《中国地质灾害与防治学报》
CSCD
2004年第4期69-72,81,共5页
The Chinese Journal of Geological Hazard and Control
基金
铁道部科技计划资助项目(2001 G 027)
关键词
隧道衬砌裂损
背后空洞
安全系数
衬砌与围岩间接触关系
fracturing failures of tunnel lining
back cavity
safety factor
contact relation between lining and surrunding rockmass
