Sequential deepening grouting construction technology and device for soil covering layer on karst cave in karst area

Abstract

The invention discloses a sequential deepening grouting construction technology and device for a soil covering layer on a karst cave in a karst area. The technology comprises two sequences, namely a front sequence and a rear sequence. Rear sequential holes are distributed among front sequential holes, and the hole depth of the rear sequential holes is increased on the basis of the front sequential holes. The front sequential holes mainly perform a function of reducing the permeability of the superficial strata, and the hole depth of the rear sequential holes is further increased than that of the front sequential holes. In this way, the sequential deepening process realizes an effect similar to that of sectional grouting, realizes emphasis reinforcing on a soil layer near a top plate of the karst cave, is as convenient as through grouting, does not need to bury orifice pipes or floral pipes, and does not need to carry out repeated drilling. The workload is greatly reduced, and the construction period is greatly shortened.

Description

【Technical field】 [0001] The invention relates to the technical field of grouting technology, in particular to a grouting construction technology and equipment for sequentially deepening the overlying soil layers of karst caves in karst areas. 【Background technique】 [0002] It has been proved through geophysical prospecting and geological drilling in the early stage that on the one hand, the K11+680-K11+740 section of a certain expressway has a relatively deep karst cave, and the thickness of the overlying soil layer ranges from 18m to 22m. On the other hand, the roof of the karst cave is generally thin. The thickness ranges from 0.4m to 0.5m. Whether this type of cave needs to be treated, and how to choose treatment measures, there are many disputes. On the one hand, deeply buried karst caves are less affected by additional stress, so karst caves exceeding a certain buried depth may not be treated. On the other hand, the bearing capacity of thin-roofed karst caves is ver...

AI Technical Summary

Problems solved by technology

Its disadvantage is that multiple times of re-drilling and re-injection are required in the process of top-down grouting in sections. Compared with the workload required for full-length grouting, the workload of orifice pipe grouting has doubled several times.

In addition, the orifice pipe grouting not only needs to consume a large amount of orifice pipes, but also causes unnecessary waste of a lot of cement slurry in the process of re-drilling

[0011] Generally speaking, the existing technology, whether it is sleeve valve pipe grouting or orifice pipe grouting, has many shortcomings. Among them, the sleeve valve pipe grouting process is complicated, the sealing is complicated, and the quality requirements of the construction team are too high; Orifice pipe grouting consumes a large amount of pipe materials and requires multiple holes, which is especially inconvenient for large-scale promotion and use

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