Excavation method of bedding slope crack toe plate protection layer of karst landform

Abstract

The invention relates to an excavation method of a bedding slope crack toe plate protection layer of karst landform. The excavation method is characterized by adopting simultaneous blasting of toe plate foundation surface bench blasting and upstream slope double-energy-gathering pre-splitting smooth surface blasting and combining a flexible cushion layer and a bench millisecond differential blasting method with a reserved protection layer; and the excavation method specifically comprises the following steps that technical disclosure is conducted; survey and setting out are conducted; blast hole positions are determined; a drill rig is in place; the drill rig starts drilling, and a hole drilling record is filled; when a blast hole is drilled to be about 40 cm, recheck is conducted, and thehole drilling angle is adjusted; the blast hole depth is controlled, and the 30-50 cm of protecting layer is reserved; as for the special geological conditions, related records are well made, and whether blasting design is adjusted or not is considered; blasting construction is conducted; according to the blasting design, the blast hole is filled with the flexible cushion layer, explosive is charged, the hole is plugged, explosive in the hole is networked, and blasting is conducted; and the protection layer is excavated. According to the excavation method of the bedding slope crack toe plate protection layer of the karst landform, the cost is saved, the mechanical utilization rate is increased, the construction progress is accelerated, and the favorable conditions are created for subsequent construction.

Description

technical field [0001] The invention belongs to the field of water conservancy and hydropower building construction, and relates to an excavation method for a dam toe slab of a concrete face rockfill dam, in particular to an excavation method for a along-slope fissure toe slab protective layer and an upstream side slope in karst landform. Background technique [0002] The research and test of one-time explosive removal method of bedrock protective layer has only a history of more than 20 years in our country. Its development is quite slow. From the perspective of fast and efficient construction, it is not yet mature, and it is still in the stage of continuous exploration and improvement. Therefore, it has not been widely used in the excavation construction of rock foundations of hydraulic structures. [0003] In the early 1950s, N.V. Melnikov, an academician of the former Soviet Academy of Sciences, made a pioneering research on "spaced charge blasting". At the same time, S...

AI Technical Summary

Problems solved by technology

The disadvantage of the first method is that it is only suitable for dam foundations with relatively complete bedrock and good geological conditions, and is not suitable for dam foundations with thin layers of joints, cracks, and faults in karst landforms.

The disadvantages of the second method are: large amount of repeated foundation clearing works, long construction period, high cost, and unsatisfactory quality

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