Determination of Critical Excavation Length of Inclined Wells with Thick Sand Layers and Gentle Slopes in Open Excavation Method and Underground Excavation Method

Abstract

The invention discloses a critical excavation length determining method of a thick sand layer gentle slope inclined shaft open excavation method and a sub-surface excavation method. The method is characterized in that open channel excavation length is calculated according to inclined shaft inclination angle, ground gradient, open channel side slope gradient, shaft excavation height, top plate safety thickness and plowing layer thickness; inclined shaft excavation grading angle and excavation inclination length are used as variable parameters to respectively calculate to obtain the building cost functions of each of the open excavation method and the sub-surface excavation method; the critical excavation length of inclined shaft open excavation and sub-surface excavation is determined by analyzing different design parameter indexes and comparing and analyzing the building cost functions. The method has the advantages that the critical excavation length of the open excavation method and the subsurface excavation method is determined from angles such as engineering mechanics and project building cost, project safety requirements can be satisfied, project building cost is effectively controlled at the same time, project benefits are increased, and theoretical basis is provided for determining the critical excavation length of the thick sand layer gentle slope inclined shaft open excavation method and the sub-surface excavation method.

Description

technical field [0001] The invention relates to the shaft construction of an inclined shaft in a coal mine. Specifically, it relates to a method for determining the critical excavation length of an open-cut method and an under-cut method for an inclined well with a gentle slope in a thick sand layer. Background technique [0002] When the common method is used for wellbore construction, the wellhead excavation methods of inclined shafts are divided into open trenches and hidden tunnels. Except for direct excavation of dark tunnels in mountainous areas with stable hillside terrain, open trench excavation is generally required to overcome wellhead coverage. The layer is thin, the soil is soft, and the roof is difficult to maintain. At present, the determination of the excavation length of the open trench and the slope angle of the open trench is mainly based on engineering experience and engineering analogy, and lacks a certain theoretical basis. Aiming at this current situa...

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Problems solved by technology

[0004] Can not scientifically and rationally calculate the critical excavation length of the open cut method and the underground method during the construction of the inclined shaft according to the existing theory, the technical solution of the present invention is solved like this:

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