摘要
根据钻探、物探资料,拟建南京地铁3号线滨江路站—五塘村站沿线穿越的灰岩地层中有数量较大的洞径为2～3m的小型溶洞。通过对该地区地质背景的分析发现,岩溶明显受断裂构造控制,溶洞发育规模小但数量多,对开挖后隧道的围岩稳定性有一定的影响。采用数值分析法研究了小型溶洞尺寸、与隧道位置关系等不同因素对隧道围岩稳定性的影响。计算结果表明,当溶洞尺寸和位置变化时,围岩塑性区也发生变化,塑性区面积随着溶洞尺寸的增大而增大。溶洞位于拱肩时塑性区面积最大,对围岩的稳定性影响大,位于拱腰时最小。隧道开挖后拱顶和拱底处最易破坏,相近条件下串珠状溶洞比单个溶洞的危害性要大。
The initial drilling survey revealed that there are many caves along with Binjiang Road Station-Wutang Village Station at proposed Nanjing Metro Line 3. Through the analysis of geological background, and combined with geophysical exploration, borehole data, found that the karst was controlled by faults significantly, the size of cave is small, but is quantity. The distribution of cave is selective, multi-layer and other features. Analysis the influence of cave to the stability of surrounding rock in different situations by numerical. The results show that, the plastic zone of surrounding rock change with the size and location of cave. The plastic zone increase with cave size. The plastic zone＇s area is largest when the cave in the spandrel, and is smallest when cave in the hance. After the tunnel excavation, the vault and dome are the most easily damaged place. It has the greatest impact on the stability of surrounding rock when the cave in the spandrel, beaded cave is more harmful than a single cave in similar conditions.
出处
《地质论评》
CAS
CSCD
北大核心
2012年第3期519-525,共7页
Geological Review
基金
高等学校科技创新工程重大项目培育资金资助项目(编号708043)
南京地铁科技资助项目的成果
