铁路隧道混凝土理论消耗量分析及计算

Quantitative Analysis and Calculation of Concrete Consumption in Railway Tunnels

混凝土超耗是隧道工程施工面临的难题,如何有效减小隧道混凝土超耗是项目成本管控的重点,也是难点。为有效降低施工成本,合理确定隧道混凝土消耗标准,做好施工管控,立足于隧道施工特点,从混凝土超耗原因、消耗组成、消耗量化分析及二次衬砌模板台车轮廓外放影响等方面,针对混凝土施工前后工序进行混凝土消耗量化计算及评估,得出:1)初期支护喷混凝土消耗量主要与设计量、回弹量及平均线性超挖量相关,喷混凝土理论消耗量是设计量的1.6~3.8倍;2)二次衬砌模筑混凝土消耗量主要与设计量及预留变形量相关,在实际预留变形量是设计预留量1/3的情况下,二次衬砌模筑混凝土理论消耗量是设计量的1.04~1.12倍;3)一般的二次衬砌模板台车结构强度及刚度较大,满足二次衬砌混凝土浇筑施工至初凝时的自重或冲击压力,定位时不需要将台车轮廓外放大,以防变形回落。

Excessive consumption of concrete is a common problem in tunnel projects.Controlling excessive consumption of concrete is both the key and most difficult aspect of construction cost control.Accordingly,to effectively reduce construction costs,reasonably determine tunnel concrete consumption standards,and perform construction management and control,the consumption of concrete before and after construction is calculated and evaluated in terms of the cause of concrete consumption,consumption composition,consumption quantitative analysis,and the influence of the outline of the secondary lining formwork trolley.The following results are obtained.(1)The consumption of shotcrete in the primary support is mainly related to the design quantity,rebound quantity,and average linear overbreak quantity,and the theoretical consumption is approximately 1.6 to 3.8 times the design quantity.(2)The consumption of concrete for secondary lining formwork is mainly related to the design quantity and reserved deformation quantity,and when the actual reserved deformation quantity is one-third of the design reserved quantity,the theoretical consumption of concrete for secondary lining formwork is approximately 1.04 to 1.12 times the design quantity.(3)The structural strength and rigidity of the general secondary lining formwork trolley are relatively large,meeting the requirements of self-weight or impact pressure of secondary lining formwork from concrete pouring to initial setting,and the trolley contour does not need to be enlarged to prevent deformation and falling back.