灰岩地区隧道排水管长期性能及化学结晶淤堵机理

Study on Long-term Performance of Tunnel Drainage Hole in Limestone Area and Mechanism of Preventing Chemical Crystallization Siltation Blocking

南方湿热多雨条件下,灰岩隧道地区排水管化学结晶淤堵是影响隧道结构安全的重要因素,为有效解决排水管化学结晶处治养护技术难题,有必要探究湿热条件下灰岩隧道排水管化学结晶淤堵机理。在模型试验的基础上,采用离散元理论及刚-柔接触理论,对灰岩隧道排水管化学结晶淤堵全过程进行了模拟计算与分析,取得了一系列成果:(1)获取了隧道工程排水管渗流作用下位移场与应力场的分布规律及特征,验证了模型试验结果的正确性;(2)根据模型试验及数值计算得出的泄水量-时间变化规律,提出了灰岩隧道排水管最佳破晶第一养护时间节点与最晚破晶第二养护时间节点;(3)揭示了灰岩隧道排水管长期性能及化学结晶淤堵机理。

Under the humid and rainy conditions in the south, chemical crystallization siltation blocking of drainage holes in limestone tunnels has become an important factor affecting the safety of tunnel structure. In order to effectively solve the technical problems of chemical crystallization treatment and maintenance of drainage holes, it is necessary to explore mechanism of preventing chemical crystallization siltation blocking of limestone tunnels under humid and hot conditions. In this paper, being based on the established chemical crystallization siltation blocking test model, the discrete element method has been used to simulate the entire seepage process of the chemical crystallization siltation body around the drainage hole, such results have been obtained as follows: The deformation and stress field of the crystallization around the drainage hole have been obtained, which have verified the correctness of the test results. Being based on seepage-time variation law from model testing and value calculation, the best crystallization-preventing time, that is the first maintenance time, as well as the latest crystallization-preventing time, that is the second maintenance time, has been pointed out. The long-term performance of tunnel drainage hole in limestone area and mechanism of preventing chemical crystallization siltation blocking have been revealed.