Elastic stress solution for complex cross section of roadways based on genetic optimization and sequential quadratic programming algorithm
HU Baowen1，2，LI Changhong1，WEI Xiaoming1，ZHOU Xiaolong1，GONG Cong3，WANG Di1
(1. Key Laboratory of High-efficient Mining and Safety of Metal Mines，Ministry of Education，University of Science and Technology Beijing，Beijing 100083，China；2. College of Water Conservancy and Hydropower，Hebei University of Engineering，Handan，Hebei 056001，China；3. Engineering Institute，Jiangxi University of Science and Technology，Ganzhou，Jiangxi 341000，China)
Abstract：The accurate conformal function determines the accuracy of stress-displacement solution for the surrounding rock of roadways with the cross section of complex shape. The genetic optimization and sequential quadratic programming algorithm are thus applied to achieve the high-precision mapping for complex shapes of the cross section. The optimization scheme overcomes the low robustness and the sensitivity of initial value existed in the previous optimization algorithms and constrains the average relative error below 0.5% when the number of mapping coefficient is greater than 14. The elastic stress solution based on the complex function methods was derived，and utilized to systematically analyze the mechanical behaviors of the surrounding rock of three-centered arch. The tangential stress curve exhibits the double peaks of unequal heights under one-way vertical load，which correspond to the small arch and right-angle area with the stress concentration factors of 1.5–3.0 and 3.5–8.0 respectively. The stress concentration factors for side wall and floor are around 2 and －1 respectively. The stress concentration factors for large arch area are －1.0–1.5. The stress distribution of surrounding rock shows that the scope of influence for right-angle area is the largest，followed by the arch area，the side wall area and the floor area. Both the stress concentration factor and lateral pressure coefficient have the strict linear relationship with the slope to be the growth rate of stress concentration factor. The tangential stress distribution on the boundary of roadway under different can be known through the distribution of .
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2017, Vol. 36 
