石林隧道底鼓灾害的特征与机理研究

STUDY ON THE FORMATION MECHANISM OF FLOOR HEAVE DISASTER IN SHILIN TUNNEL

基于石林隧道现场地质调查及底鼓灾害的特征分析,得到了围岩特性、地层压力、地下水、支护形式和围岩流变等诱发该隧道底鼓灾害的因素;通过深入分析各种因素的致灾过程,表明石林隧道底鼓灾害是一种集遇水膨胀性和挤压流动性为一体,且极具时效变形特性的综合型底鼓。考虑底板下近断层的影响,将石林隧道底板岩层视为板壳结构,通过理论分析得到基于非关联诱导因子群作用下隧道底鼓量的估算公式,表明隧道底板岩层弯曲失稳引起的底鼓量对总底鼓量起关键控制作用。研究结果可进一步深化对隧道底鼓灾害的认识,为灾害防治措施的制定提供可靠依据。

Based on the analysis of floor heave disaster appeared in the Shilin tunnel, and the survey of the field geology of the section, the induction factors of floor heave, such as characteristic of surrounding rock, formation pressure, underground waver, supporting conditions and the rheology property are demonstrated. Through analyzing the formation mechanism caused by different induction factors deeply, it is indicated that the disaster appeared in Shilin Tunnel is comprehensive floor heave, which posses the characteristics of water swell, extrusion flow and time effect. Considering the influence of the horizontal fault, the tunnel floor is treated as shell structure, and the estimate formula of the displacement for it is suggested. Moreover, the formula is in the consideration of non- associate inducible factors. The important conclusion is that the bending displacement of the tunnel floor takes up a significant proportion of the total displacement. The above results can further deepen the understanding about the formation mechanism of the floor heave disaster induced by the horizontal fault. And it also provides a reliable reference to the disaster prevention of tunnel floor heave.