A grouting reinforcement method for soft rock tunnels

Abstract

The invention discloses a grouting reinforcement method for soft rock tunnels. The grouting materials include ordinary Portland cement, rapid-hardening sulphoaluminate gelling agent and water; the quality of the water is the same as that of ordinary Portland cement and rapid-hardening The total mass ratio of the sulfoaluminate gelling agent is 0.46:1, and the mass ratio of the rapid hardening sulfoaluminate gelling agent to ordinary Portland cement is (0.67-1.5):1; the grouting reinforcement material The initial setting time is 40±5min, and the average compressive strength of the cube after solidification for 4h is ≥10MPa. The grouting material of the present invention has the advantages of fast grout coagulation speed, simple preparation, high strength and rapid hardening, and is suitable for the rapid construction requirements of soft rock tunnels.

Description

technical field [0001] The invention belongs to the technical field of construction engineering, and relates to a high-strength rapid-hardening grouting material and a grouting reinforcement method for soft rock tunnels. Background technique [0002] my country is already the country with the largest tunnel project scale, the largest number and the fastest construction speed in the world. By the end of 2017, 14,040km / 15,181 road tunnels had been built, and 15,781km / 14,700 railway tunnels had been built by the end of 2017. [0003] The central and western regions are dominated by mountains and heavy hills, and the terrain and geological conditions are complex and changeable. The development of transportation will inevitably encounter a large number of tunnel projects. With the improvement of tunnel construction standards and construction scale, it is a huge challenge to safely and efficiently traverse high-in-situ stress soft rock areas, especially when crossing soft, loose ...

AI Technical Summary

Problems solved by technology

[0005] (1) The early strength is low, and the surrounding rock cannot be reinforced in time and the anchoring force of the bolt can not be provided. Under the action of frequent construction disturbances (especially blasting vibration), the initial support is prone to settlement and deformation, and it is separated from the surrounding rock, and then pulled up. The surrounding rock is loose, which induces large deformation disasters

[0006] (2) The coagulation speed of the grout is slow, and it is easy to be diluted and lost under the action of groundwater, resulting in poor grouting quality

[0007] (3) The designed water-cement ratio is unreasonable, and it is not uncommon to see too thin cement slurry with W / C=1:1

[0008] (4) The on-site dosing of tunnel grouting is inaccurate. For grout with complex grouting materials (especially too many external admixtures), it is easy to miss or repeatedly add some admixture, and the process is complicated and difficult to popularize and apply

[0009] (5) The effect is minimal and the reaction is obvious

For soft rock, the ordinary Portland cement slurry commonly used in tunnels not only fails to achieve the desired effect, but also has little reinforcement or anchoring effect. The rock has been infiltrated for a long time, and the softening effect is obvious, which increases the load of the surrounding rock on the tunnel and aggravates the softening and deformation of the surrounding rock of the tunnel

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