Concrete pumping extrusion pouring construction method for tunnel secondary lining

Abstract

The invention discloses a tunnel secondary lining concrete pumping extrusion pouring construction method, comprising S1: dividing the tunnel into an arched pouring area at the top and several layers of bottoms located on both sides of the tunnel and below the arched pouring area In the pouring area, the pouring area of ​​each floor is approximately symmetrically distributed on both sides of the tunnel; S2: Concrete pumps are used to pour concrete in the pouring area of ​​each floor in sequence from bottom to top; this construction method enhances the compactness of concrete, improves the strength of concrete, and reduces The quality defects of the second lining concrete have improved the construction quality of the second lining of the tunnel.

Description

technical field [0001] The invention relates to the technical field of tunnel pouring, in particular to a construction method for tunnel secondary lining concrete pumping extrusion pouring. Background technique [0002] Secondary lining concrete pouring is an important part of tunnel construction, and the choice of secondary lining concrete pouring method directly affects the construction quality of tunnel secondary lining. The quality defects of various traffic tunnel secondary linings have always been a major hidden danger affecting the later operation. During the construction process Due to the influence of human factors, technological factors, technical factors, etc., it is easy to cause quality defects such as the second lining concrete is not dense, the back is empty, the vault is empty, and the strength of the concrete is insufficient, which brings great difficulties to the repair of defects in the later stage. At present, the construction method usually uses the deli...

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Problems solved by technology

[0002] Secondary lining concrete pouring is an important part of tunnel construction, and the choice of secondary lining concrete pouring method directly affects the construction quality of tunnel secondary lining. The quality defects of various traffic tunnel secondary linings have always been a major hidden danger affecting the later operation. During the construction process Due to the influence of human factors, technological factors, technical factors, etc., it is easy to cause quality defects such as the second lining concrete is not dense, the back is empty, the vault is empty, and the strength of the concrete is insufficient, which brings great difficulties to the later repair of defects.

At present, the construction method usually uses the delivery pipe to pump the concrete to the vault, and then uses the chute to perform synchronous and symmetrical pouring window by window on both sides. Due to the long distance of concrete transportation and flow, there are many diversions and the flow rate of a single chute is limited. The diameter of the pipe and the delivery pump truck have high requirements on the slump and workability of the concrete, which requires the concrete to have good fluidity. In order to improve the fluidity of the concrete, it is necessary to add water to adjust the concrete and reduce the pouring window. Will reduce the quality of concrete construction

In addition, the general tunnel construction follows the "window-by-window pouring" method. When the chute is poured, the concrete flows down from a high place and passes through the dense steel reinforcement layer in the middle, which will lead to serious separation of aggregate and grout, reduce the strength of concrete, and produce quality defects such as honeycomb pockmarks.

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