Construction method for grouting reinforced region applied to water-rich sand layer shield tunnel

Abstract

The invention belongs to the field of tunnel construction, and particularly relates to a construction method for a grouting reinforced region applied to a water-rich sand layer shield tunnel. According to the technical scheme, the construction method comprises the following steps that 1, parameters of the grouting reinforced region and a grouting control mode are determined; 2, a grouting pump islaid to open reserved grouting holes on a segment; 3, grout is transported to a grout storing tank at the tail portion of a shield; 4, the grout is grouted synchronously through the reserved groutingholes on the segment to form the grouting reinforced region; and 5, the effect of the grouting reinforced region is monitored. According to the construction method for the grouting reinforced region applied to the water-rich sand layer shield tunnel, the grouting reinforced region formed for a sand layer can play a good role in strengthening and stopping water, the price of the grout is low, the amount of grouting is low, no secondary grouting is needed, and the construction process is easy to operate.

Description

technical field [0001] The invention belongs to the field of tunnel construction, and in particular relates to a construction method for a grouting reinforcement ring applied to a shield tunnel in a water-rich sand layer. Background technique [0002] During the excavation construction of subway tunnels in areas with water-rich sand layers using the shield method (the diameter of the shield tunnel is 6-6.5m), the grouting reinforcement ring of the shield tunnel is the main means to solve the water gushing of the project. It is also an important process in the construction of shield tunneling in water-rich sand layer. The purpose of grouting in tunnel engineering: on the one hand, it is used to reduce the permeability of the soil layer and block the flow of groundwater; on the other hand, it is to use the strength of the grouting layer to improve the bearing capacity of the surrounding rock. The excavation of the shield tunneling in the water-rich sand layer requires synchro...

AI Technical Summary

Problems solved by technology

It has short grout setting time, high grout solid strength, certain anti-seepage and anti-seepage effects, and can better control the initial settlement and stability of the tunnel. However, there are the following disadvantages when using double grout grouting: ① The grout is easy to block the grout delivery pipe; ②The amount of grouting is 150%-200% higher than the theoretical value, which increases the grouting cost; ③The grouting process is not easy to control, and the grouting cannot be in place at one time, and a second grouting is usually required

However, the horizontal jet grouting pile reinforcement method has the following disadvantages: ①The reinforcement quality is easily controlled by human factors; ②There are many uncertain factors in construction; ③Insufficient inspection methods for the pile reinforcement effect

The use of deep mixing pile reinforcement methods has the following limitations: ①The reinforcement depth is generally less than 10m; ②High requirements for construction operations; ③The water-stopping effect on water-rich sand layers is not obvious

[0004] Generally speaking, the construction method of grouting reinforcement ring reinforcement and water-stop for excavation of shield tunnels in water-rich sand layers is still based on experience, and cannot meet the needs of subway construction in my country under the geological conditions of water-rich sand layers

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