Drilling process for surveying land pebble-filled limestone cave

Abstract

The invention relates to a drilling process for surveying a land pebble-filled limestone cave. Different from a traditional process, the drilling process for surveying the land pebble-filled limestonecave comprises the process steps of (a) measuring a hole position, then adopting a first drilling tool to start drilling, and protecting a wall for a hole drilled at the upper end of a rock base plane after drilling to the rock base plane; (b) then drilling a limestone cave layer top plate surface, cleaning the hole to be below a limestone cave layer bottom plate surface, then lift-drilling, andrecording the distance between the limestone cave layer top plate surface and the limestone cave layer bottom plate surface; (c) configuring a core barrel with a drill bit according to the distance instep (b) so as to form a second drilling tool, then using the second drilling tool to drill the limestone cave layer bottom plate surface, and keeping the core barrel with the drill bit in the drilled hole so as to protect the wall, wherein the wall protecting range is at least from the limestone cave layer top plate surface to the limestone cave layer bottom plate surface; (d) adopting a third drilling tool with the diameter being smaller than the inner diameter of the core barrel for drilling and coring in the core barrel to a designed hole depth; and (f) after finishing drilling and coring, taking the core barrel out. The drilling process for surveying the land pebble-filled limestone cave involved in the invention has high construction efficiency.

Description

technical field [0001] The invention relates to the field of geological survey, in particular to a drilling technique for surveying and filling cobble soil karst caves. Background technique [0002] With the expansion of urban construction scope and the densification of traffic network, some building foundations have to be located in areas with strong karst development. It is particularly important to find out the karst development law of construction sites, provide basis for foundation design, and ensure the safety and reliability of buildings. However, due to the abundance of groundwater in some karst areas, beaded karst caves are developed, often filled with loose pebble soil. During the survey process, the retaining mud completely leaked out, and the filling pebble soil immediately collapsed after lifting the drill, making it difficult to drill the hole, which seriously affected the construction quality and progress. At present, this kind of stratum drilling is commonly...

AI Technical Summary

Problems solved by technology

The former is often difficult to follow the pipe when drilling in multi-layer pebble soil caves, and requires multiple layers of casing, which consumes a lot of manpower and materials, and the drilling efficiency is extremely slow; Effects and other factors often consume huge costs, and may not be able to achieve significant results

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