隧道混凝土超耗成因分析及应对措施

Causes Analysis of Excessive Consumption of Tunnel Concrete and Corresponding Measures

长期以来,隧道施工中的混凝土超耗率始终居高不下,严重制约着企业的生产利润。为有效控制隧道混凝土超耗顽疾,首先以铁路及公路两个行业为研究对象,基于实测统计数据分别对比分析初支、二衬及仰拱3个环节的混凝土超耗量。结果表明,铁路隧道二衬、仰拱超耗率远高于公路隧道,其仰拱超耗率近3倍于公路隧道;公路行业隧道混凝土总体超耗量为34.45%,略低于铁路行业隧道混凝土超耗量40.62%,其原因在于行业管理标准、超耗控制意识及控制水平的差异。然后分析当前铁路行业隧道混凝土超耗控制存在的问题,并进一步制定针对性措施。最后为控制混凝土超耗,提出喷射混凝土掺加增黏剂、一循环一分析动态调整爆破参数及动态调整初支预留变形量3个创新举措。研究成果可为隧道混凝土超耗控制提供借鉴。

The overconsumption rate of concrete in tunnel construction has remained high for a long time,seriously restricting the production profits of enterprises.To effectively control the stubborn problem of excessive concrete consumption in tunnels,the excessive consumption of concrete in the three links of primary support,secondary lining,and invert in the railway and highway industries was compared first based on measured statistical data.The results show that the overconsumption rate of railway secondary linings and inverts is much higher than that of highways,and the overconsumption rate of railway inverts is nearly three times that of highways.The overall overconsumption of tunnel concrete in the highway industry is 34.45%,slightly lower than the 40.62%of tunnel concrete in the railway industry.The reason is differences in industry management standards,overconsumption control awareness,and control levels.Then,the problems existing in the current tunnel concrete over-consumption control in the railway industry was analyzed.Targeted measures were further developed.Finally,three innovative measures were introduced to control excessive consumption of concrete,including adding a tackifier to shotcrete,dynamically adjusting blasting parameters in one cycle and one analysis,dynamically changing the reserved deformation amount for the initial support.The research results can provide a reference for controlling excessive concrete consumption in tunnels.