Advanced grouting reinforcement method for water-rich sand layer shield interval contact channel

Abstract

The invention discloses an advanced grouting reinforcement method for a water-rich sand layer shield interval contact channel. The method comprises the steps that 1, preliminary grouting reinforcementis conducted on a stratum at the ends of a channel; 2, the channel stratum is integrally grouted and reinforced; 3, supplementing grouting reinforcement is carried our on the stratum at the end partsof the channel. The method is reasonable in design, easy and convenient to construct and good in reinforcing effect, the advanced to-be-reinforced area of the water-rich sand layer contact channel stratum is divided, effective reinforcing is conducted through the grouting reinforcing method of the corresponding type, the reinforced stratum and a shield segment of the constructed shield tunnel arefixedly connected into a whole, the structure stability of the shield tunnel can be effectively improved while the stratum reinforcing effect of the constructed contact passage is further improved, the ground surface settlement of the shield tunnel can be effectively limited and even avoided, a foundation is laid for contact passage excavation, the collapse risk of the contact passage is reduced,and the construction safety is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of construction of communication passages between shield tunneling tunnels, and in particular relates to an advanced grouting reinforcement method for communication passages between shield tunneling tunnels in water-rich sand layers. Background technique [0002] In the subway tunnel construction project, in order to meet the needs of emergency evacuation and drainage, it is necessary to set up communication channels in the shield section. The construction risk of the communication channel is relatively high, and it has always been the accident-prone part of the subway construction. Communication channel accidents can easily lead to damage to ground cables and buildings, and even endanger the entire subway line. Therefore, the communication channel construction plays a pivotal role in shield tunneling construction. However, for water-rich sand layer areas, due to the loose sandstone structure, large porosi...

AI Technical Summary

Problems solved by technology

However, for water-rich sand layer areas, due to the loose sand and gravel structure, large porosity, poor self-stability of the ground, and high excavation risks, how to ensure the construction quality and safety of communication channels has become an urgent problem to be solved

At present, the conventional construction scheme adopted for underground excavation of connecting passages in subway intervals in water-rich sand layers not only has a long period, but also has a serious impact on the construction of other processes. The most important thing is that construction safety risks are relatively high, and safety accidents are extremely prone

In terms of ground reinforcement, jet grouting piles are now mainly used for reinforcement. During the reinforcement process of jet grouting piles, not only has a great impact on the ground, but also when the communication channel is buried deep, the construction is difficult and the investment cost is high, and the construction period cannot be effectively guaranteed.

[0003] During the construction of conventional communication channels, in terms of excavation, there is a great risk of collapse when excavating the weak roof support area at the junction of the tunnel and the communication channel. This part is excavated in two stages. Excavate upwards to the design vault of the connecting channel with a slope to form a transition section. In the second stage, after the initial support is penetrated, the transition section is excavated in reverse to meet the design requirements. There is a great risk of collapse. Due to the loose sandstone structure, large void ratio, and poor self-stability of the ground, the risk of collapse is greater when excavating the weak area of ​​advanced support at the top where the tunnel connects with the communication channel. Therefore, a safer method is now needed. The advanced grouting reinforcement method of the communication channel in the shield section of the water-rich sand layer to reduce the occurrence of accidents

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