金华山软岩隧道纤维混凝土初期支护试验研究

Experimental Investigation on the Fiber Reinforced Concrete Early Lining of Jinhuashan Railway Tunnel in Soft Rock Mass

混凝土中掺入聚丙烯纤维可以提高混凝土的延性,有利于混凝土支护结构和围岩共同作用。将湿喷工艺和纤维混凝土应用于隧道支护结构可以提高支护结构的施工质量和围岩的自承载能力,介绍了金华山隧道纤维混凝土支护结构的设计,材料的选用。为了评价湿喷纤维混凝土支护结构支护效果,采用现场试验量测的方法量测了对比段和试验段围岩压力、混凝土支护层压力,并进行了数据分析。分析结果表明,采用纤维混凝土支护结构试验段围岩压力分布均匀,围岩压力数值较小,混凝土支护层压力数值较小;对比段围岩压力数值要略大于试验段围岩压力,对比段混凝土支护层压力数值大于试验段混凝土支护层压力数值;纤维混凝土试验段支护效果良好。

Concrete reinforced with polypropylene fiber can improve the concrete flexibility and facilitate the interaction between concrete lining structure and rock mass. The fiber reinforced concrete and wet spraying technique are used in the early lining of Jinhuashan railway tunnel in soft rock mass for improving the construction quality of lining structure and the self-bearing capacity of wall rock. The design and material selection for the fiber-reinforced concrete lining of Jinhuashan Tunnel are described. To evaluate the lining effect, site measurement of the wall rock pressure, concrete lining pressure of both the section under test and that for comparison was made. The analysis of the measurement data shows that the wall rock of the section under test has a uniform pressure and smaller values of both wall rock pressure and concrete lining layer while those values of the section for comparison are higher, with the wall rock pressure only slightly higher. The fiber- reinforced concrete has a good lining effect.