Construction method for reducing blasting vibration of structure close to urban tunnel

Abstract

The invention discloses a construction method for reducing blasting vibration of a structure close to an urban tunnel. The method comprises the following steps of a, during construction, moving cutting holes downwards to be away from an upper protected structure, arranging double-layer small guide pipes within the range of 4 m in front of and behind an underneath pass section, performing advance support, enabling the length of the small guide pipes to be 4 m, enabling the distance between every two adjacent small guide pipes to be 30 cm, performing construction once every other arch frame, driving locking foot anchor pipes strictly according to the designed depth, adding the locking foot anchor pipes at the arch waist, and effectively welding L-shaped ribs and locking feet; b, dividing anexcavation area at the upper part of the tunnel into a first area and a second area, firstly slotting a hole in the first area at the middle lower part of the step, arranging a blast hole and an electronic detonator detonating line, and carrying out blasting excavation of the first area with the excavation process of 0.5m to 1m to form a pilot tunnel so as to provide a complete free surface for other blast holes; and c, after the construction passes through the adjacent structure, arranging a second-area cutting hole, arranging a blast hole and an electronic detonator detonating line, carryingout blasting excavation of the second area, and finally expanding excavation to a designed contour line.

Description

technical field [0001] The invention belongs to the field of tunnel engineering, and in particular relates to a construction method for reducing the blasting vibration of structures adjacent to tunnels in urban areas. Background technique [0002] With the continuous acceleration of the domestic urbanization process and the rapid development of the transportation industry in large central cities, the construction of urban underground transportation has shown a trend of increasing, and there have been many shallow buried hard rock underground tunnel projects in central urban areas. Considering the suitability, economy and technical applicability of the excavation method, the drill and blast method will continue to be the main construction method for tunnel excavation. Since the drilling and blasting method will cause vibration in a certain range of the blasting area, when the vibration reaches a sufficient intensity, it will have an impact on the environment. Facing the comp...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a construction method for reducing the blasting vibration of urban tunnel adjacent structures in view of the existing Class V surrounding rock tunnel construction across the urban area, which cannot satisfy the safety and stability of the adjacent structures on the ground when three-step blasting is used for construction.

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