摘要
运用FLAC3D,系统研究动荷载振幅、频率以及工程因素对竖向排列地下硐室群稳定性的影响,并实例分析地下硐室群在爆破震动作用下的稳定性。研究结果表明,振幅对地下硐室群稳定性的影响最明显,隔板对动荷载具有放大效应,当振幅等于0.5 m.s-1时,放大系数为1.35,放大系数随动荷载振幅的增大而增大;围岩塑性区面积也随振幅增大而增大。隔板位移量随频率的增大先减小后增大,50 Hz的高频动荷载对地下硐室群稳定性最不利;隔板最大位移量随硐室间距的增大而减小,随上方硐室跨度的增加而增大,硐室间距越大,上方硐室的跨度越小,对地下硐室群稳定性越有利。动荷载作用下地下硐室群围岩出现较大的应力集中,但最大拉应力小于岩体的抗拉强度,地下硐室群围岩不会出现拉裂破坏。结合工程实例,分析爆破震动作用下地下硐室群的稳定性,分析结果表明,沿硐室群轴线方向,洞口位移量最大,中间部分的位移量最小,这与实际监测结果一致。
Influence of amplitude, frequency of dynamic loads and engineering factors on the stability of vertical arranged underground caverns is studied systemically with FLAC^3D, and the stability of underground caverns under blasting vibration is analyzed with example. The results show that the influence of amplitude on the stability of underground caverns is most obvious, and the interlayer can magnify the effects of dynamic loads. When the amplitude is 0.5 m · s^-1, the magnifying coefficient is 1.35. The magnifying coefficient and the area of plastic zone of surrounding rock increase with the increase of amplitude. The displacement of interlayer increases at the beginning and then decreases later with the increase of frequency. And the dynamic load of 50 Hz is most disadvantageous for the stability of underground caverns. With the increase of distance between two caverns, the displacement of interlayer decreases, which is advantageous for the stability of underground caverns. The displacement increases with the increase of span of above cavern. Stress concentration occurs in surrounding rocks, while the maximum tension stress is less than the tensile strength of rock mass, so tensile crack does not take place. The stability of underground caverns under blasting vibration is analyzed through engineering case. The results show that the displacement of entrance is maximal and the displacement of middle part is minimum along with the axes of underground caverns. It agrees well with the observed results.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2006年第3期27-33,共7页
China Railway Science
基金
国家自然科学基金重点资助项目(50490272)
国家'十五'科技攻关项目(2003BA612A-10-2)
