摘要
为研究上覆岩层厚度对浅埋偏压小净距隧道稳定性的影响,采用有限差分软件FLAC3D,模拟了隧道在不同上覆岩层厚度下围岩的位移、应力集中系数和塑性区的分布情况,并将不同工况下围岩的位移和力学特征进行了对比分析。研究结果表明:在浅埋偏压条件下,上覆岩层厚度小于6 m(0.5B)时,浅埋侧岩体和中夹岩柱塑性区范围显著增大。随着上覆岩层厚度的增加,最大竖直位移增加,最大水平位移增长缓慢,浅埋侧岩体塑性区和中夹岩柱塑性区减小,拱脚塑性区扩大。浅埋侧岩体、中夹岩柱、拱肩和拱脚处是浅埋偏压小净距隧道的薄弱部位。建议:上覆岩层厚度小于6m(0.5B)时,对浅埋侧地表和中夹岩柱进行重点加固。上覆岩层厚度增加后,对中夹岩柱、隧道拱脚和拱肩进行重点加固。
In order to study the influence of overlay stratum thickness on the stability of shallow bias neighborhood tunnel, the finite difference software FLAC3D was used to simulate the distribution of the surrounding rock displacement, stress and plastic zone of the tunnel at different overlay stratum thickness, the displacement and mechanical characteristics of the surrounding rock under different conditions were compared.The results show that in the conditions of shallow buried,with less than 6 meters of overlay stratum thickness,the plastic zone of shallow side rock and middle rocky column increased significantly.As the overlay stratum thickness increased, the maximum vertical displacement increased, the maximum horizontal displacement increased slowly, the plastic zone of shallow side rock and middle rocky column decreased, and the plastic zone of arch foot increased. When overlay stratum thickness was less than 6 meters,the shallow side surface and the middle rocky column should be reinforced. As the overlay stratum thick- ness increased,the middle rocky column,spandrel and arch foot should be reinforced.
出处
《交通科学与工程》
2015年第4期59-65,共7页
Journal of Transport Science and Engineering
基金
国家自然科学基金资助项目(51278071
51308072)
湖南省教育厅科学研究项目(14B007)
关键词
浅埋偏压
FLAC3D
上覆岩层厚度
应力集中系数
shallow covered slope
FLAC3D
overlay stratum thickness
stress concen-tration factor
