基于现场试验的超大双曲面穹顶洞库支护体系研究

为解决硬岩中超大型地下工程复合式衬砌二次衬砌模筑混凝土施工困难、模板工程复杂、混凝土圬工量大等问题，以某地下储油库为依托，应用有限差分计算软件与现场原位试验的方法，对大型地下工程进行力学机制研究及支护体系优化。研究结果表明： 1）在围岩条件较好的岩体中开挖大型地下洞室，在支护参数选择合理、施工质量得以保证的前提下，使用单层喷射混凝土衬砌可提高施工效率，减少混凝土用量； 2）采用聚丙烯纤维喷射混凝土支护+低预应力锚杆的优化支护体系相较于Q系统岩石支护表所得的支护参数可更好地控制围岩变形，减少支护结构与围岩的拉应力区，达到与复合式衬砌接近的支护效果； 3）现场试验后发现优化后的支护体系在变形与应力方面可达到预期效果，穹顶最大变形约8 mm，支护结构安全可靠。

Support System Optimization of Super Large Cavern with Hyperboloid Dome

The secondary lining formwork of the composite lining in super large underground engineering in hard rock has several disadvantages, such as difficulty in concreting, complicated formwork engineering, and excess concrete masonry work. Accordingly, a case study is conducted on an underground oil storage depot, and the finite difference calculation software and on site in situ test are employed to analyze the mechanical mechanism and optimize the support system for large scale underground engineering. The results reveal the following: (1) When excavating a large underground cavern in the rock mass with good surrounding rock conditions, a single layer shotcrete lining can improve construction efficiency and reduce the amount of concrete under the premise of reasonable support parameters and guaranteed construction quality. (2) Compared with the 〖WT５《TNR#I》〗Q〖WT５《TNR》〗 SYSTEM rock support table, the optimized support system of polypropylene fiber shotcrete support and prestressed bolt can better control the deformation of surrounding rock and reduce the tensile stress area of the support structure, achieving a support effect close to that of the composite lining. (3) After the field test, the deformation and stress of the optimized support system are acceptable, and the maximum deformation of the dome is approximately 8 mm, indicating a safe and reliable support structure.