强膨胀岩浅埋富水隧道变形分析及施工控制-《高速铁路技术》

文章信息/Info

Title:: Deformation Analysis and Construction Control of Heavily Expansive Rock Tunnels with Shallow-buried Rich Water

Author(s):: LIU Jianguo; WANG Chunming; XUE Ninghong; BAI Weiwei; China Railway Seventh Group Co., Ltd., Zhengzhou 450016, China

Keywords:: heavily expansive rock|shallow buried rich water|tunnel|deformation analysis|control

摘要:: 昆明铁路枢纽呈贡双线铁路隧道区属滇池断陷盆地及滇中高原丘陵-中低山区地貌，隧道拱顶埋深6~28 m，测区地震动峰值加速度为0.2 g，经室内土样试验，平均自膨胀率为51%，阳离子交换量为370 mmol/kg，蒙脱石含量为54.6%，天然含水量ω=37.68%，为典型的高烈度地震区强膨胀岩浅埋富水隧道。为确保隧道的施工和运营安全，通过现场测试，掌握了高烈度地震区浅埋大跨强膨胀土围岩条件下隧道开挖后的洞周变形规律、强膨胀土对支护结构的围岩压力变化规律等，对隧道开挖及支护的稳定性进行了分析，并根据变形监测分析进行了施工组织优化，达到了控制变形的目的。

Abstract:: Chenggong double-track railway tunnel of Kunming Railway Hub belongs to the graben basin of Dian Lake and the plateau hills of central Yunnan. The burial depth of the tunnel vault is 6~28 m. The ground motion peak acceleration of the testing zone is 0. 2 g According to the test data of indoor soil sample, the average self-expansion rate of the soil is 51%,the cation exchange capacity is 370 mmol/kg,the montmorillonite content is 54. 6%,and the natural moisture content ω=37. 68%, which indicates that it’s the typical strong expansion rock shallow buried rich water tunnel. In order to ensure safety of construction and operation, the deformation rules of shallow-buried large-span tunnel with heavily expansive soil surrounding rock in high intensity seismic area and the change rules of surrounding rock pressure of heavily expansive soil on supporting structure are mastered. The stability of excavation and support of tunnel is analyzed, and the optimization of the construction organization is carried out to achieve the goal of controlling the deformation according to the deformation monitoring analysis.