论文部分内容阅读
衬砌与围岩是水工隧洞的主要组成部分,外水压力是其承担的主要荷载之一.结合某水电站工程实例,建立其发电引水隧洞的有限元数值分析模型,针对衬砌与围岩有条件联合承载作用特征,对衬砌外围岩变形模量进行折减以反映围岩的作用,并引入具有一定抗拉强度的薄层单元量化反映衬砌与围岩有条件联合承载能力.结果表明:与衬砌完全单独承载外水压力计算结果相比,围岩在承担外水压力中的作用不容忽视,且随着外围岩体变形模量的增加,其所分担的外水压力越大;采用薄层单元量化后,衬砌与围岩的联合承载机理更为明确,薄层单元开裂前,围岩承担外水压力较多,薄层单元开裂后,衬砌承担外水压力较多,因而要确保回填灌浆和固结灌浆质量,以提高衬砌与围岩联合承载能力.
Lining and surrounding rock are the main components of hydraulic tunnel, and external water pressure is one of the main loads.Based on the engineering example of a hydropower station, the finite element numerical analysis model of the diversion tunnel is established, The bearing capacity of lining is reduced to reflect the effect of surrounding rock and the thin layer element with a certain tensile strength is introduced to quantify the joint bearing capacity of lining and surrounding rock.The results show that Compared with the calculation results of the external water pressure of the lining alone completely, the role of the surrounding rock in the external water pressure can not be neglected, and as the deformation modulus of the surrounding rock mass increases, the greater the external water pressure is shared; After the unit is quantified, the joint bearing mechanism between the lining and the surrounding rock is more definite. Before the thin-walled unit cracks, the surrounding rock will bear more external water pressure. After cracking of the thin-walled unit, the lining will bear more external water pressure and thus ensure the backfill grouting And consolidation grouting quality, in order to improve the joint bearing capacity of lining and surrounding rock.