莲花水电站四通岔管施工稳定问题研究

Research on the stability of the construction of underground intersected chambers in the Lianhua hydropower station

莲花水电站四通岔管为一大跨度小交角的地下交叉洞室。根据三维有限元应力分析和脆性材料试验，无衬砌时最危险断面在最大开挖断面和岔裆断面之间变化，不应采用不对称刚性支护。据此，施工中应对危险断面和危险点采用合理的加强锚喷支护方式，并采用适当的施工程序和施工方法，严格控制施工质量。

The underground intersected chambers have a large span and a small intersection angle. The three-dimensional finite element stress analysis shows that the meen the maximum excavated section and crotch section, and that the asymmetric rigid support is unreasonable. The result of the fragile material experiment hasalso proved this conclusion. Therefore, the dangerous sections and positions should be strengthened by guniting and anchoring suppport, and appropriate construction procedure and method should be used to control thequality of construction strictly.