砂卵石地层空洞的安全性定量评价方法浅析

Analysis on Quantitative Evaluation of the Safety of Cavity in Sandy Pebble Stratum

随着北京、成都等地地铁建设的蓬勃发展,由盾构等人为扰动所形成的地层空洞也频频发生,严重威胁地面行人以及建构筑物安全。目前对于砂卵石这种特殊土层地层空洞的形成及其受力及演化方式的认识不充分,对其安全性的判定没有较为明确的定量判定。本文通过对实际施工成拱特性的受力机理进行分析,结合数学计算推导出地层空洞的成拱高度计算表达式,同时借用这一转换条件提出了一种砂卵石地层空洞的安全性定量评价方法。

With the rapid development of subway construction in Chengdu and Beijing etc.,the cavities caused by the shield driving occur frequently,leading to a serious threat to the ground level pedestrian and building safety.The research on the formation and evolution of the cavity in the sandy pebble stratum is not sufficient,and there is also no clear way to determine its safety. Based on the analysis on mechanism of stress arch during the actual construction and by the mathematical derivation,a way to calculate the height of the cavity stress arch in sandy pebble stratum is put forward. And based on this conversion,a quantitative way to evaluate the safety of cavity in sandy pebble stratum is put forward.