Vertical shaft working face ahead pre-grouting method

Abstract

The invention discloses a vertical shaft working face ahead pre-grouting method which comprises the steps that a thick liquid stopping pad construction is carried out, wherein after a vertical shaft driving working face reaches a thick liquid stopping pad position, a grouting hole opening pipe, a checking hole opening pipe and a water filtering pipe are arranged according to the position and the dipping angle, a water filtering layer is paved, and then concrete placing is carried out; wall-back grouting is carried out, wherein back-wall cement thick liquid injection is carried out on the shaft wall of a supported vertical shaft; and pre-grouting is carried out, wherein after the steps are carried out, hole drilling is carried out from the buried the grouting hole opening pipe until water inflow amount exceeds preset amount, at the time, drilling is stopped, thick liquid is injected, after thick liquid is subjected to final setting, hole cleaning is carried out until water inflow amount exceeds the preset amount, then drilling stopping is carried out, thick liquid in injected until water inflow amount is smaller than the preset amount, then hole drilling is carried out continuously, the steps are carried out repeatedly, subsection-down type hole drilling grouting is carried out, and hole cleaning is carried out to the full depth. A pre-burying grouting hole opening pipe and shaft wall back-wall grouting are combined, working face drilling hole grouting is carried out through the grouting hole opening pipe, full blocking of a water inflow working face developed from a vertical shaft rock joint fissure is achieved, and the advantages of a short working period and good water blocking effect are achieved.

Description

technical field [0001] The invention belongs to the technical field of mine construction, and in particular relates to an advanced pre-grouting method for a shaft working face with short construction period, good water blocking effect and safe shaft construction. Background technique [0002] Grouting is to inject grout into the pores, cracks or cavities of rock and soil. The grout is diffused, solidified and hardened to reduce the permeability of rock and soil, increase its strength and stability, and achieve the purpose of rock and soil reinforcement and water blocking. It can not only be used for "dry well drilling" construction in order to reduce water gushing in the wellbore, speed up the drilling speed, and pre-grout all aquifers within the full depth of the wellbore, but also block water in fractured water-bearing strata and loose sandy soil layers. reinforcement. Grouting is one of the main methods of sinking wells and water control in mine construction, and it is a...

AI Technical Summary

Problems solved by technology

[0004] The existing pre-grouting construction of the vertical shaft working face mostly has technical problems such as long construction period, poor water blocking effect and poor safety of the supported shaft wall for the bedrock aquifer with high-angle fractures

The pre-grouting period is long, mainly due to low drilling and injection efficiency and long auxiliary time

The main reasons for the poor water blocking effect are: firstly, the construction quality of the grout stop pad is poor, it is not resistant to high pressure, and it is easy to leak grout during grouting; The water is still gushing during construction; the third is that the drilling is shallow, and the aquifer blocked by one grouting is less; the fourth is that the grouting pressure is low, the grout diffusion range is small, and it is easy to gushing water again after the blasting vibration

The main reason for the poor safety of the supported shaft wall is that in the prior art, only grouting is used to plug the leaking section of the shaft wall, and the surrounding rock of the shaft wall has very poor self-stabilization ability, such as mudstone swelling and disintegration when encountering water. , the surrounding rock is subject to the control of the joint structure, and it is easy to form wedge-shaped unstable rock blocks, which are easy to damage the well wall and cause safety accidents; In addition, the well wall with poor surrounding rock stability will also have potential safety hazards in blasting and rock drilling after pre-grouting. , it is difficult to guarantee the safety of shaft construction

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