Analysis of Largespan Highway Tunnel Surrounding Rock Vertical Pressure Attributes

Abstract:

Based on the monitoring of the Longtou Mountain largespan tunnel surrounding rock pressure,a study is made of the relationship of vertical pressure,buried depth and surrounding rock grade.The road tunnel design code method,M M theory method and Bilbawumyer theory method are respectively used to calculate the surrounding rock pressure.In the rock grades IV or V,the value calculated by M M theory method and the actual value are about the same,the value calculated by the road tunnel design code method and the value calculated by Bilbawumyer theory method are greater than the actual value; in the rock grade Ⅱ or Ⅲ,the value calculated by the road tunnel design code method and the actual value are about the same,the value calculated by M M theory method value is smaller than the actual value,and the value calculated by Bilbawumyer theory method is greater than the actual value; in the relationship of surrounding rock pressure and buried depth,the variation trends of the road tunnel design code method value and Bilbawumyer theory method value are similar to the actual value,but they are greater than the actual value.the value calculated by M M theory method is close to the average actual value.The applicability of different calculation methods of surrounding rock pressure is studied for the largespan tunnel,which provides a reference for largespan tunnel design.