岩溶分布对盾构隧道力学特性的影响分析

Analysis on the Infl uence of Karst Distribution on the Mechanical Characteristic of Shield Tunnel

深圳地区喀斯特地质较为发育,主要表现为覆盖型喀斯特,进行合理的喀斯特处理尤为重要。文章主要研究了盾构隧道沿线穿越的喀斯特发育区域处理方案,通过计算,分析溶洞位于底部、侧边、顶部不同间距时隧道于施工期和运营期的受力特征。计算结果表明,盾构隧道在施工期主要受底部和侧向溶洞影响较大,宜针对隧道侧面5 m、顶部3 m、底部10 m范围内的溶洞进行处理;在运营期,若不处理喀斯特,底部溶洞对隧道影响最大,宜采取溶洞回填的方式强化地层抗力。

The karst geology in Shenzhen area is relatively developed,which is mainly manifested as covered karst.It is particularly important to carry out reasonable karst treatment.This paper mainly studies the treatment scheme of karst development area along the shield tunnel.Through calculation,the stress characteristics of the tunnel during construction and operation period when the karst cave is located at the bottom,side and top with different distances are analyzed.The calculation results show that the shield tunnel is mainly affected by the bottom and side karst caves during the construction period,and the karst caves within the range of 5 m on the side,3 m on the top and 10 m at the bottom of the tunnel should be treated.During the operation period,if the karst is not treated,the bottom karst cave has the greatest influence on the tunnel,and the karst cave backfill should be adopted to strengthen the stratum resistance.