Karst geology rotary-drilling bored concrete pile hole forming process

Abstract

The invention discloses a karst geology rotary-drilling bored concrete pile hole forming process which includes the steps of 1, leveling a field; 2, paying off at a pile foundation; 3, setting a rotary drilling machine in place; 4, embedding a pile casing; 5, preparing mud stabilizing liquid and filling the mud stabilizing liquid into the pile casing; 6, forming holes by means of rotary drilling (with requirements of reducing drilling speed when drilling in karst caves or half rocks, otherwise, drilling to reach designed elevation ); 7, performing primary cleaning of holes and hole depth checking; 8, mounting a reinforced cage and a conduit; 9, performing secondary cleaning through air-lift reverse circulation; 10, pouring underwater concrete (while preparing extra 30-40 cubic meters of concrete with consideration of karst caves so as to prevent pile scrap caused by breakdown of the karst caves and sharp sinking of concrete); and 11, forming a pile and removing the pile casing.

Description

technical field [0001] The invention relates to a pile foundation construction technology, in particular to a karst geological rotary-dug cast-in-place pile hole-forming technology. Background technique [0002] The construction technology of rotary drilling bored pile is a pile foundation construction technology that has emerged in recent years. At present, the existing construction technology of rotary drilling bored piles is: leveling the site → laying out the pile position → placing the rotary drilling rig in place → laying the casing → supplementing the stabilizing fluid in the casing → rotary digging to form a hole → clearing the hole and inspecting the hole Deep → install reinforcement cages and conduits → secondary hole cleaning → pouring underwater concrete → forming piles and pulling out the casing. The existing construction process quality control standards and construction process technical standards have no specific national construction method standards. The ...

AI Technical Summary

Problems solved by technology

The existing construction technology is aimed at the general geological conditions. If the general geological rotary drilling pile construction technology is copied in the karst area with complex geological conditions, different problems will arise. The most important problem is the deviation of the borehole. , Drill sticking, drill bit drop, incomplete hole cleaning, broken piles and waste piles, etc.

Due to the poor stability of the drilling rig installation, the unstable installation of the drilling rig or the bending of the drill pipe during operation, the soft ground or uneven hardness and other reasons, the drilling hole is deflected; , it will lead to problems such as drill sticking or bit drop; the rock fragments produced during the process of rotary drilling in karst areas are more than those in general geology, and the general hole cleaning method will cause incomplete hole cleaning, which will lead to There is a lot of sediment at the bottom of the pile, which seriously affects the quality of the pile foundation; due to the existence of karst caves, the karst caves may be broken down when pouring concrete, resulting in a sharp decline in the concrete, resulting in broken piles and waste piles

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