Karst grouting reinforcement water-stop constructing method

Abstract

The invention discloses a karst grouting reinforcement water-stop constructing method, which is to construct according to sizes of karst caves by adopting a principle of from big to small regarding a certain area, construct by adopting a principle of from outside to inside for the karst caves with the same size, and construct by adopting a principle of from the bottom to the top in a vertical direction. On the basis of the construction principles, the method comprises the following steps of: (1) forming grouting holes by adopting a core drill; (2) forming construction exhaust and drainage pressure relief holes; (3) inserting grouting pipes into the grouting holes, wherein the grouting pipes comprise steel pipes, grouting shock pipes and sleeve valve pipes; (4) cleaning the holes, wherein when the step (3) is completed, the grouting pipes are cleaned with clean water; (5) grouting; and (6) drawing out the grouting pipes after the grouting is completed, and blocking the grouting holes with cement mortar or concrete. By adopting the constructing method, the pertinence to karst caves is strong, the grouting quantity is small, the engineering work amount is small, the cost is low, and the effect of filling and reinforcing is good.

Description

technical field [0001] The invention relates to a method for strengthening and stopping water by karst grouting. Background technique [0002] At present, in covered karst areas, the existing karst grouting reinforcement technologies at home and abroad mainly use sleeve valve pipe grouting method, high-pressure rotary spraying method or riprap sand filling method. For open caves such as karst caves that have been excavated and are visible to the naked eye, riprap is used to fill them with sand or backfill them with plain concrete. For complex karst caves and karst cavities systems below the surface, the holes are arranged at equal intervals throughout the site and treated with sleeve valve pipe grouting. The grouting pressure is 0.3~3.0MPa. The grouting material is mainly cement slurry, followed by cement slurry and water. Glass combined double slurry. For some fully-filled karst caves that have been identified, single-pipe or double-pipe high-pressure rotary spraying meth...

AI Technical Summary

Problems solved by technology

[0004] 1. The pertinence is not strong: For example, in southern China, karst caves have a huge development scale, different filling conditions, high groundwater level, and good connectivity. For unfilled or semi-filled karst caves, the sleeve valve is used to inject cement slurry, just like in a pond or The cement slurry is injected into the river, the filling and reinforcement effect is poor, or even invalid

[0005] 2. Large amount of grouting, poor economy: unfilled karst caves have good circulation. When injecting cement slurry or double-fluid slurry, because the groundwater is in a flowing state, the slurry is lost or diluted seriously, and the amount of grouting is large, which is economical. Very low benefit

[0006]3. Large amount of engineering and long construction period: the grouting holes are mostly densely distributed at equal intervals, and the spacing is generally 1.5~2.0m. When grouting, there is blindness Therefore, the amount of grouting is uncontrollable, the cost is high, and the construction period is long. The amount of grouting in a single hole in Guangzhou has reached more than 1,400 cubic meters. The total project cost budget is more than 30 million yuan, and the completion price is as high as 120 million yuan.

[0007]4. The effect of filling and reinforcement is not satisfactory, and there are blind spots: the single-tube or double-tube high-pressure rotary spraying method is used for reinforcement, the reinforcement range is limited, the quality of the reinforcement is unstable, or there are Grouting reinforces the blind area and becomes a channel for groundwater runoff

[0008]5. The grouting reinforcement method is single, and no complementary and complete grouting reinforcement system has been formed

[0009]6. For the southern region with high groundwater level and large water volume, karst water spray may be caused after excavation of foundation pit. If riprap sand filling method is used, it will not be successful , it can only be implemented after the water is stopped