大田一号隧道洞门仰坡蠕滑体整治方案-《高速铁路技术》

文章信息/Info

Title:: On Treatment for Creep Mass on the Upward Slope at the Portal of Datian No.1 Tunnel

Author(s):: XIANG Lirong; LIU Gang; HUANG Qi; China Railway Eryuan Engineering Group Co., Ltd., Chengdu 610031, China

Keywords:: upward slope at portal|creep mass|anti-slide pile|anchor frame beam|treatment scheme

摘要:: 贵广高速铁路大田一号隧道施工过程中，隧道进口仰坡山体发生了蠕动滑移，形成蠕滑体。在仰坡前缘继续临空及雨季地表水下渗进一步软化土体的情况下，该蠕滑体极有可能形成较大范围的工程滑坡，对工程带来较大的安全隐患。依据仰坡蠕滑体的工程地质条件、形成原因及稳定性评价，本文针对该蠕滑体采用多种措施相结合的综合整治方案进行治理：在垂直于蠕滑体主滑面的滑动方向上设置两排抗滑桩（共设置14根），确保蠕滑体整体稳定性满足要求；在坡面设置锚杆框架梁护坡，确保蠕滑体局部稳定性满足要求；采用粘土夯填裂缝，在蠕滑体四周设置环形天沟，降低水对蠕滑体的不利影响。整治方案效果良好，可为类似隧道仰坡不良地质的加固处理提供借鉴。

Abstract:: During the construction of Datian No.1 Tunnel on Guiyang-Guangzhou High-speed Railway, the massif on the upward slope at the portal of the tunnel crept, and creep mass has been formed. Under the condition that the front edge of the upward slope continues to be exposed to the air and the infiltration of surface water in the rainy season further softens the soil, it is very likely that the creep mass will form a large-scale landslide caused by construction activities, which will bring great potential safety hazards to the project. According to the geological conditions, formation reasons, and stability evaluation of the creep mass on the upward slope, this paper adopts a comprehensive treatment scheme combining various measures to treat the creep mass: two rows of anti-slide piles (14 in total) are set in the sliding direction perpendicular to the main sliding surface of the creep mass to ensure that the overall stability of the creep mass meets the requirements; slope protection with anchor frame beam is set up on the slope to ensure that the local stability of creep mass meets the requirements; clay tamping is used to fill cracks, and annular gutter is set around the creep mass to reduce the adverse effects of water on the creep mass. The treatment scheme is proved a good effect, which provides a reference for the reinforcement of similar tunnel slopes with unfavorable geological conditions.