无粘结环锚预应力混凝土衬砌应力状态分析

无粘结环锚预应力混凝土衬砌是有压水工隧洞采用的一种新型衬砌型式,由于衬砌结构组成体系复杂,导致其内部应力状态分布极为复杂,且在不同工况下受力会发生显著变化。为了解该结构在施工期和运行期的受力状态,并及时掌握衬砌安全状况,对小浪底排沙洞环锚预应力衬砌张拉期和运行期的应力状态进行了研究。采用等效荷载法和实体建模法相结合的方法建立数值模型,通过对应力状态计算和应力状态现场实测值进行对比,明确了不同工况下预应力衬砌受力状态。研究结果表明,小浪底排沙洞环锚衬砌在张拉期和运行期预应力状态都处于安全范围。研究结果对无粘结环锚预应力混凝土衬砌的设计、施工具有重要参考意义。

Stress state analysis of pre-stressed concrete lining with un-bonded annular anchors

The pre-stressed tunnel lining with un-bonded annular anchors is a new lining form used in pressure hydraulic tunnel. Due to the complexity of the structural system, its internal stress state is extremely complicated and varies greatly under different conditions. In order to understand the stress state of the lining system during construction and operation, and to grasp the safety status of the lining in time in construction and operation periods, the stress states of the un-bonded annular anchors lining of sediment discharge tunnel of Xiaolangdi Hydropower Station during the stress tension period and the operation period were analyzed. A numerical model was established by combining the equivalent load method and solid modeling method, and the calculated stress state was compared with the in-situ measured one. Based on this, the stress states of pre-stressed concrete lining under different conditions were revealed. The analysis results show that the pre-stressed annular anchors of Xiaolangdi Dam sediment discharge tunnel is in a safe state during the tension period and the operation period, which are of important reference significance for the design and construction of pre-stressed concrete lining with un-bonded annular anchors.