Energy-saving type tunnel advanced small pipe fast-assembly grout stopping structure

Abstract

The invention discloses an energy-saving type tunnel advanced small pipe fast-assembly grout stopping structure which comprises a holding force clamp, a sliding die sleeve and an elastic grout stopping plug; the holding force clamp clamps the end, stretching out of a tunnel face, of an advanced small pipe; the sliding die sleeve is arranged on the outer side of the holding force clamp in a sleeving manner and is in sliding fit with the holding force clamp; the elastic grout stopping plug wraps the outer side of the sliding die sleeve and is used for blocking a gap between the advanced small pipe and a hole wall; and a rotary thrust sleeve pushes the sliding die sleeve and the elastic grout stopping plug to move synchronously through a pushing bolt. According to the energy-saving type tunnel advanced small pipe fast-assembly grout stopping structure, a base for positioning and pushing the elastic grout stopping plug is provided through firm connection of the holding force clamp and theadvanced small pipe; under the action of pushing force, the elastic grout stopping plug extrudes and blocks a gap between a drilled hole and the outer wall of the advanced small pipe; and the operation is simple, convenient and flexible without waiting for concrete setting, so that the working procedure time is shortened, construction circulation is promoted, the construction efficiency of a grouting construction staff is improved, grouting material waste and cost investment are reduced, the grouting construction efficiency and the grouting effect are improved, and the situation that stuffingcannot form when a jet of water in the drilled hole is serious is avoided.

Description

technical field [0001] The invention belongs to the technical field of fast installation and stoppage of a small leading conduit, and in particular relates to an energy-saving structure for quick installation and stoppage of a small leading conduit in a tunnel. Background technique [0002] The tunnel site is constructed in a plateau area with an altitude of more than 3,500 meters. The construction area has high altitude, harsh climate, and high environmental protection requirements. The oxygen content and air pressure value are only 65% ​​of the normal value. The ventilation length of the long tunnel in the plateau alpine area is long, and affected by the environment of low pressure and low oxygen content, the efficiency of construction equipment and personnel efficiency are seriously reduced. Energy saving control is particularly important in tunnel advance small conduit grouting construction. [0003] Usually the tunnel is constructed with a small conduit in advance, and...

AI Technical Summary

Problems solved by technology

[0003] Usually the tunnel is constructed with a small conduit in advance, and the gap between the borehole wall and the outer wall of the small conduit is sealed with cement mortar, anchoring agent, expansion cement, etc. After -60min, when it can bear the specified maximum grouting pressure and water pressure, use high-pressure grouting pump to grout. The grouting can be terminated in 15min-20min, and the nozzle of the small grouting conduit is blocked to prevent the grout from flowing back out of the pipe. This method has many disadvantages: First, the solidification time of the filler is 30min-60min, which prolongs the tunnel construction cycle time, which violates the principle of "quick support and early closure" in tunnel construction; secondly, because the material of the filling is different from that of the surrounding rock of the tunnel, the filling is hard material, and the filling shrinks during the solidification process, which may easily cause thirdly, the tunnel is constructed underground, and there is mostly groundwater in the surrounding rock of the tunnel, and there is seepage or even strands of water flowing out of the borehole, and the filling is affected by the disturbance intensity of the groundwater during the filling and solidification , in severe cases, strands of water may even cause the filling to fail to form; fourth, in the on-site construction, the drilling of the surrounding rock of the advanced small conduit depends on the surrounding rock, using a 50mm-60mm drill bit to form the hole. The specification of the advanced conduit used in the general design and construction is hot-rolled Seamless steel flower tube, outer diameter 42mm, wall thickness 3.5mm, the gap area between the wall of the drilled hole and the outer wall of the small conduit is 5.78-14.41 square centimeters, the maximum pressure of the advanced small conduit is controlled at 1Mpa, and 1Mpa is equivalent to 10kg The items act on the construction area per square centimeter. During the grouting operation, the outward thrust of the cement slurry on the filler is equivalent to the force of 57.8-144.1kg of items. If the pump pressure fluctuates up and down, consider a safety factor of 1.25 , the thrust will also increase, which needs to generate greater friction through the filler between the wall of the borehole and the outer wall of the small conduit, so as to resist the outward thrust of the grout on the filler during grouting; Fifth, the traditional tunnel site In construction, the gap between the borehole wall and the outer wall of the small conduit is usually used. The filler grouting method requires the construction personnel to mix the filler material on site and manually fill the gap between the drill hole and the small conduit. It is not easy to fill densely, and the construction operation is complicated. , waste of materials, filling quality is not easy to control the disadvantages

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