A Method for Estimating the Radius of Tunnel Curtain Grouting Reinforcement

Abstract

The invention discloses a method for estimating a tunnel curtain grouting reinforcement radius. The method comprises the steps that data is collected on a construction site, the water pressure of allpartition areas of cross sections of front sections of tunnel faces, surrounding rock strength, surrounding rock particle adjustment coefficients and boundary influence coefficients of a cavity for all partition areas of equivalent cross sections are obtained through reconnaissance and tests, the uprush strength, of all the partition areas of the cross sections of the front sections of the tunnelfaces and the uprush intensity of the equivalent cross sections are estimated, and the uprush hidden danger degree of sections of the cross sections the front sections of the tunnel faces is determined; a management quality target of a curtain grouting reinforcement area is set, and the corresponding uprush intensities G1, G2 and G3 of the equivalent cross sections are estimated when the effectiveradius of curtain grouting management reaches 1r, 3r and 5r separately; a planar coordinate system with r as the horizontal axis and G as the longitudinal axis is established, coordinate points of (1r, G1), (3r, G2), (5r, G3) are labeled, the three coordinate points are smoothly connected through a fitted curve, and finally a coordinate point (nr, +64%) on the curve is found out; at this moment,nr is the corresponding effective management radius, and the grouting influence radius is subtracted from nr to obtain the estimated curtain grouting reinforcement radius.

Description

technical field [0001] The invention relates to a tunnel and underground engineering surge disaster analysis method, in particular to a method for estimating the radius of tunnel curtain grouting reinforcement. Background technique [0002] For tunnel sections with serious inrush hazards, or tunnel breach sections where major inrush disasters have occurred, curtain grouting is required to reinforce the surrounding rock to provide safety conditions for subsequent excavation work. In curtain grouting design, the first problem encountered is how large the radius of curtain grouting reinforcement is appropriate. This problem has puzzled tunnel designers for a long time. In order to solve practical problems, people generally use the theoretical calculation method or the empirical analogy method. Zhang Minqing et al. introduced the two traditional methods systematically in the book "Underground Engineering Grouting Technology". [0003] The so-called empirical analogy method is t...

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Problems solved by technology

The analogy method is also a more scientific method, but the actual operators have no fixed formula reference, or the analogy case is not suitable for the actual tunnel, or they do not have a comprehensive grasp of the situation and data of the analogy case, and there are personal subjective opinions There are large deviations from the actual situation, etc., which will affect the implementation effect of the analogy

However, the theoretical calculation does not take into account the fact that the distribution of hydrogeological conditions in the tunnel section and section is not necessarily uniform, and there is a large deviation between the calculated results and the actual situation.

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