型钢框架-锚索-岩土体耦合蠕变行为

Coupled Creep Behavior in Steel Frame-Anchor Cables-Rock and Soil Mass

通过现场试验,揭示了型钢框架-锚索-岩土体的耦合蠕变行为,建立了支护体系耦合效应下锚索蠕变模型和锚固力损失计算模型.基于蠕变损伤理论构建了锚固力损失过程中等效蠕变刚度损伤计算模型.研究结果表明,粉土地层中,拉力型锚索在有效锚固长度范围内增加锚固段长度可提高其抵抗蠕变能力,压力型锚索受锚固体挤胀作用影响,可有效减小锚固力损失.型钢框架-锚索-岩土体耦合蠕变模型及锚固力损失计算模型皆展现出较好的计算效果,等效蠕变刚度损伤模型可有效预测等效蠕变刚度的损失状态,并准确描述锚固力的衰减规律.

Through field tests, the coupled creep behavior of the steel frame-anchor cable-rock and soil mass is revealed, and the creep model and the anchoring force loss calculation model of anchor cable under the coupling effect of the support system are established. In addition, a calculation model of equivalent creep stiffness damage in the process of anchoring force loss is constructed based on the creep damage theory. The research results demonstrate that increasing the length of the anchorage section within the effective anchorage length range of the tensile anchor cable can improve its creep resistance in silty soil. Meanwhile, the compression anchor cable can effectively reduce anchoring force loss due to the expanding effect of the anchorage section. Both the steel frame-anchor cable-rock and soil mass coupled creep model and the anchoring force loss calculation model show excellent calculation results. The equivalent creep stiffness loss model can effectively predict the loss state of equivalent creep stiffness and accurately describe the attenuation law of anchoring force.