基于突变理论的隔水岩体失稳分析及安全厚度计算
Instability analysis and safe thickness calculation of waterproof rock mass based on mutation theory
方林 1龚晟 2王桂林 2余浩2
作者信息
- 1. 招商局重庆交通科研设计院有限公司,重庆 400067
- 2. 重庆大学土木工程学院,重庆 400044
- 折叠
摘要
为了保障岩溶突水隧道施工和运营安全,基于弹性梁模型,应用突变理论建立岩溶突水顶板在动力扰动下失稳的双尖点突变模型;综合考虑围岩性质、静水压力、动力扰动等因素,分析岩溶突水隧道顶板的失稳机制和破坏条件,建立其失稳突变的判别方程,并采用Matlab软件编程,求解顶板的最小安全厚度;同时,为了避免当静水压力过大时,突变理论公式的不合理性,单独计算仅在静水压力的情况下的最小安全厚度,并取两者计算值中的更大值.结果表明:隔水岩体是否保持稳定是由岩体内外因素共同决定的;岩体跨度越长,岩体最小安全厚度越大;岩体弹性模量越大,岩体最小安全厚度越小.在振动频率一定时,爆破荷载越大,岩体最小安全厚度越大;在爆破荷载的大小一定时,爆破振动的频率越大,岩体最小安全厚度越小;静水压力越大,岩体最小安全厚度越大.该岩溶突水隧道顶板安全厚度计算方法具有可行性与较高的准确性.
Abstract
In order to ensure the safety of the construction and operation of the karst water inrush tunnel,based on the elastic beam model,double cusp mutation model of the instability of the karst water inrush roof under dynamic disturbance was established by using the catastrophe theory.Considering the surrounding rock properties,hydrostatic pressure,dynamic disturbance and other factors,the instability mechanism and failure conditions of the roof of karst water inrush tunnel were analyzed,the discriminant equation of its instability mutation was established,and the minimum safe thickness of the roof was solved by Matlab software programming.At the same time,in order to avoid the irrationality of the theoretical formula of the mutation when the hydrostatic pressure was too large,the minimum safe thickness of the hydrostatic pressure was calculated separately,and the greater value of two calculated values was taken.The results show that whether the waterproof rock mass remains stable is determined by the factors the internal and external factors of rock mass.The minimum safe thickness of the rock mass increases with the increase of the span of the rock mass,and decreases with the increase of the elastic modulus of the rock mass.When the vibration frequency is constant,the greater the blasting load,the greater the minimum safe thickness of rock mass.When the blasting load is constant,the greater the frequency of blasting vibration,the smaller the minimum safe thickness of rock mass.The greater the hydrostatic pressure,the greater the minimum safe thickness of rock mass.The engineering example shows that this method of calculating the safety thickness of the roof of karst tunnel is feasible and highly accurate.
关键词
突变理论/隔水岩体失稳/安全厚度/动荷载/静水压力Key words
mutation theory/waterproof rock mass instability/safe thickness/dynamic loading/hydrostatic pressure引用本文复制引用
出版年
2024
NETL
NSTL
万方数据