约束混凝土拱架力学特性与截面设计方法研究

Study on mechanical properties and section design method of confined concrete arch

随着地下工程逐渐向深部发展,传统支护体系难以满足复杂条件下的支护需求,约束混凝土拱架具有良好的承载特性,在地下工程中逐渐被广泛应用,但截面特性对约束混凝土拱架力学性能的影响机制尚未明确。对比分析常见的方钢约束混凝土(SQCC)、圆形约束混凝土(CCC)与U36全比尺拱架力学性能,研究各拱架的承载性能和变形破坏机制。对不同壁厚的SQCC,CCC和不同长宽比的矩形约束混凝土(RCC)拱架进行数值试验,研究截面形状、尺寸对约束混凝土拱架力学性能的影响机制。研究表明,在截面用钢量相同的情况下,拱架截面面积越大,承载能力越强,且SQCC,RCC拱架的力学性能优于CCC拱架。在此基础上,提出约束混凝土拱架截面设计方法。

With the underground engineering come to the deep underground region,the traditional support system is difficult to satisfy the request of support under complex conditions.Confined concrete arch had good bearing characteristics which has been successfully applied in underground engineering.However,the influence mechanism of section characteristics on the mechanical properties of confined concrete arch was still not clear.The mechanical properties of full-scaled square confined concrete(SQCC),circular confined concrete(CCC)and U36 arches were compared and analyzed.The bearing performance and deformation failure mechanism of each arch were studied.Besides,numerical tests were carried out on SQCC,CCC with different wall thickness and rectangular confined concrete(RCC)arch with different length width ratio.The influence mechanism of section shape and size on the mechanical properties of confined concrete arch was studied.The research showed that the larger the cross-sectionalarea of the arch was,the stronger the bearing capacity was,and the mechanical properties of SQCC andRCC arches were better than those of CCC arches.On this basis,the design method of confined concretearch section was proposed.