公路隧道衬砌背后空洞对围岩压力分布影响的研究

地质雷达检测结果表明，衬砌背后存在空洞是隧道施工质量典型缺陷之一，在缺陷段衬砌易出现开裂。尽管实际施工中对空洞进行了注浆处治，但仍常常发现衬砌裂损病害。在隧道安全评估计算中，当采用荷载结构法时，计算模型仅仅只对空洞处不施加荷载及约束条件，其它条件与没有空洞缺陷部位相同，这种计算结果与现场病害出现部位不符。介绍以数值试验为主要手段，通过地层结构法对不同部位及宽度的空洞衬砌进行分析，以期找出衬砌背后空洞对围岩压力分布影响的规律，对以往荷栽结构计算模型进行修正，为隧道衬砌结构病害评估、处治及养护措施提供理论依据。

Research on Influences of Cavities Behind the Lining of Highway Tunnels on Pressure Distribution of Wall Rocks

In recent years geological radar has been extensively applied in tunnel inspection. The results of inspection show that existence of cavities behind the lining is one of typical defects of construction quality of tunnels, and in sections with these defects, lining is subject to cracking. In practical construction, although cavities are treated by grouting, crack damage diseases to lining are often found. In addition, in safety evaluation calculation of tunnels, when the load structure method is adopted, the calculation model only does not apply load and constraints at cavities, and the other conditions are the same as those for parts without cavity defects. Practices prove that the calculation results of this method are not compliant with parts of diseases on site. As a result based on the above reasons, this paper analyzes cavity lining at different parts and widths via stratum structure method with numerical test as principal means, hoping to find out the law of influences of the cavities behind the lining on pressure distribution of wall rocks and modify the previous load structure calculation model so as to provide a theoretical basis for evaluation, treatment and maintenance measures for structural diseases of tunnel lining.