Analyzing the Calculation of Surrounding Rock Pressure and the Influencing Factors for Small Section Tunnel with Ⅳ and Ⅴ Grade Surrounding Rock
The small section tunnel(SST)is widely used in mine works,water conveyance and flood discharge engineering,electric power engineering,and so on.Due to the influence of rock integrity,excava-tion technology,and the cross-section type of SST,there are some differences in the surrounding rock pressure(SRP)of tunnel.Based on calculating SRP of SST with Ⅳ and Ⅴ grade surrounding rock,the calculation of SRP and the analysis of influencing factors were carried out.The research shows that,(1)In the design code of highway tunnel(DCHT),the basic quality grade of rock mass,excavation width and collapse arch range are comprehensively considered,so its method is more suitable for SRP of small section tunnel with Ⅳ and Ⅴ grade surrounding rock;(2)The Ⅴ grade surrounding rock section basically has no self-stability,and the initial support of grouting is not to take effect,and the tunnel vault is prone to rock fall.(3)When the arch rise of the small section tunnel of the circular arch straight wall is greater than 1.0 m,the attenuation of SRP is accelerated,and the worse the integrity of the rock mass(Ⅴ-level surrounding rock),the faster the attenuation.
small section tunneldeep tunnelsurrounding rock pressurepressure coefficient ratiodistribution pressure ratio
万方数据
维普
