摘要
为考虑土体参数的变异性对隧道开挖面稳定性的影响,基于可靠度理论,采用三维弹塑性有限元数值模拟方法,计算管棚预支护条件下隧道开挖面极限支护力;以不同工况下地层参数及其极限支护压力比作为样本,待BP神经网络训练完毕后,即可预测大量给定地层参数工况下的开挖面极限支护压力比,对其进行统计,得到概率分布特征;在理论分析的基础上,结合工程实际,建立了管棚预支护条件下隧道开挖面稳定的极限状态方程,运用粒子群优化算法,对其进行可靠度分析。研究结果表明:采用管棚预支护的隧道,开挖面支护压力存在极限值,达到该值后,增加较小幅度的支护力,就能较大程度地提高隧道开挖面稳定的可靠度。
In order to account the variability of soil parameters,reliability method to assess tunnel excavation face stability was proposed.The limit support pressure at tunnel face was studied by elasto-plastic finite element method.First,BP neural net work was trained with parameters of surrounding rock and ratio of limit support pressure of tunnel face as training samples.After training,the net work can predict ratio of limit support pressure when lots of parameters were imported.The statistical character of ratio of limit support pressure was gained.Limit state function of face stability of tunnel with pipe roof reinforcement was established,and reliability was solved with the particle swarm optimization.Results show that there exists a critical value of support pressure.Exceeding this value,a small increase of supporting force will greatly enhance the reliability of tunnel face stability.
出处
《中国安全科学学报》
CAS
CSCD
北大核心
2011年第11期122-127,共6页
China Safety Science Journal
基金
中国博士后基金资助(20110491537)
大连理工大学海岸和近海工程国家重点实验室开放基金资助(LP1112)
关键词
隧道
管棚预支护
开挖面稳定
粒子群优化算法
可靠度
tunnel
pipe roof reinforcement
face stability
particle swarm optimization
reliability
