CN102787855A - Excavating and supporting method of roadway containing quicksand layer - Google Patents

Abstract

The invention discloses an excavating and supporting method of a roadway containing a quicksand layer; the method comprises the following steps that (1) before the roadway is excavated, a slip casting pipe is arranged into the quicksand layer in front of an excavation direction along the design section line of the roadway, cementing slurry is injected into the quicksand layer by a slip casting pump, so that the quicksand layer is cemented together, and then an advanced temporary supporting method is adopted; (2) the roadway is excavated through a conventional excavating method, and anchor mesh spray primary supporting is carried out through a conventional supporting method after safe footage is reached; (3) anchor rope secondary supporting is carried out, a steel strand with the diameter being phi 12mm to 16mm and the length being 5m to 8m is adopted as an anchor rope, and the anchoring length needs to be more than 1m; and (4) U-shaped steel telescopic supports are used for enhancing the supporting, and the spacing between the U-shaped steel telescopic supports is 0.8m to 1.0m. According to the excavating and supporting method of the roadway containing quicksand layer, the problems that the quicksand layer is easy to collapse so that the formation of the roadway is difficult and the construction is unsafe are solved; and in addition, the supporting capability is improved, so that the deformation of the roadway after being supported is greatly improved, and the requirement of long-term stability is met.

Description

The tunnelling supporting method that contains drift sand formation

Technical field

The present invention relates to the tunnelling supporting method.

Background technology

In colliery underworkings (especially crossdrift) driving, often run into the situation that drift sand formation is passed in the tunnel at present, as adopting common temporary lining measure, drift sand formation collapses easily during tunneling construction, and drift section is difficult to be shaped, and it is also dangerous to construct; And the excavation back adopts common anchor net spray supporting method to be difficult to reach supporting effect as simple; Top board just showed tangible distortion increase phenomenon when supporting was accomplished one month; Deflection reaches more than the 500mm; Two help distortion also at 300mm simultaneously, rate of deformation reaches 11mm/d, has exceeded the ultimate deformation that general bolt support allowed; The pallet phenomenon of caving under bolt support, occurs simultaneously, be difficult to reach supporting effect.

Summary of the invention

For addressing the above problem, the present invention proposes the tunnelling supporting method that a kind of safety is passed drift sand formation.

The technical scheme that the present invention takes is that the laneway support method of glued soft rock and drift sand formation a little less than a kind of safety is passed is characterized in that it may further comprise the steps:

The first step, before tunnelling, along squeezing into Grouting Pipe in the drift sand formation in tunnel design section alignment driving the place ahead, in drift sand formation, inject glued slurries with grouting pump; Making drift sand formation glued is one, takes leading temporary lining method again, promptly on drift section overhead pulley profile, beats spacing 0.3m; Diameter 38mm, the boring of dark 3.0m, 1 inch steel pipe or φ 30 round steel of the long 4m of insertion in the boring; Insert the outer termination of exposing of leaving 1.0m of back boring, and set up the arched frame canopy and hold steel pipe and expose the termination;

Second step, by conventional driving method excavation tunnel, carry out anchor net spray once supporting by conventional supporting method after reaching safe drilling depth;

Behind the 3rd step, the anchor net spray once supporting, carry out the anchor cable secondary supporting again, anchor cable adopts the steel strand of Φ 12-16mm, length 5-8m, and anchorage length should be greater than 1m;

Behind the 4th step, the anchor cable secondary supporting, adopt U-shaped steel collapsible timbering to add strong supporting again, U-shaped steel collapsible timbering spacing 0.8-1.0m.

In order further to strengthen supporting effect, when the anchor cable secondary supporting, can install the reinforcing bar ladder beam at the back position simultaneously; Described reinforcing bar ladder beam is the truss that is welded with reinforcing bar.

The invention solves the roadway forming difficulty that drift sand formation collapses easily and causes, the construction unsafe problems; And increased support capacity, make supporting after roadway deformation obtained bigger improvement, reached the long-time stability requirement.

Description of drawings

Fig. 1 is the sectional schematic diagram of the embodiment of the invention.

The specific embodiment

With reference to accompanying drawing and the described technical scheme of summary of the invention, those skilled in the art can implement.

The first step in the face of technical scheme specifies down.

1, Grouting Pipe employing diameter is that 1 inch, length are the steel pipe of 3.5m, the some apertures of quincuncial arrangement on the steel pipe tube wall, and the aperture is 6mm, and pitch-row is 200mm, and the steel pipe tube head is fined away.

2, the installation of Grouting Pipe also should meet following regulation:

The Grouting Pipe spacing should be confirmed according to the country rock situation.When adopting individual layer to arrange, its spacing is preferably 200～400mm; When adopting double-deck the layout, its spacing is preferably 400～600mm, and levels should be staggeredly arranged.

The outer subtended angle degree of Grouting Pipe should be confirmed according to the thickness of the glued arch of slip casting, be preferably 10 °～25 °.

Grouting pressure should be generally 0.5～1.0MPa according to the decision of stratum compactness extent.

Claims (2)

1. tunnelling supporting method that contains drift sand formation is characterized in that it may further comprise the steps:

The first step, before tunnelling, along squeezing into Grouting Pipe in the drift sand formation in tunnel design section alignment driving the place ahead, in drift sand formation, inject glued slurries with grouting pump; Making drift sand formation glued is one, takes leading temporary lining method again, promptly on drift section overhead pulley profile, beats spacing 0.3m; Diameter 38mm, the boring of dark 3.0m, 1 inch steel pipe or φ 30 round steel of the long 4m of insertion in the boring; Insert the outer termination of exposing of leaving 1.0m of back boring, and set up the arched frame canopy and hold steel pipe and expose the termination;

Second step, by conventional driving method excavation tunnel, carry out anchor net spray once supporting by conventional supporting method after reaching safe drilling depth;

Behind the 3rd step, the anchor net spray once supporting, carry out the anchor cable secondary supporting again, anchor cable adopts the steel strand of Φ 12-16mm, length 5-8m, and anchorage length should be greater than 1m;

Behind the 4th step, the anchor cable secondary supporting, adopt U-shaped steel collapsible timbering to add strong supporting again, U-shaped steel collapsible timbering spacing 0.8-1.0m.

2. the tunnelling supporting method that contains drift sand formation as claimed in claim 1 is characterized in that, when the anchor cable secondary supporting, installs the reinforcing bar ladder beam at the back position simultaneously.