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。
The secondary lining formwork of the composite lining
in superlarge 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 onsite insitu test are employed to analyze the mechanical mechanism and
optimize the support system for largescale underground
engineering. The results reveal the following: (1) When excavating a large
underground cavern in the rock mass with good surrounding rock conditions, a
singlelayer 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.
