Construction method for reducing frost heaving effect borne by derrick foundation

Abstract

The invention provides a construction method for reducing frost heaving effect borne by a derrick foundation, which includes the procedures: mixing white polyethers and black esters according to a weight ratio, mixing well and spraying into a middle space of a casing for foaming; using drill bits of different diameters to perform two-stage or multi-stage broaching according to the diameter of the outer wall of an insulation layer of a freezing pipe after freezing borehole boring is complete, and cleaning bottom of a borehole and tripping the pipe after broaching is complete; splitting a hard polyethylene casing from the single side after a weld is cooled naturally, respectively connecting the split casing to insulation segments in an overlap joint manner, and pouring the well mixture of the black and the white materials into a joint binding space for foaming. Polyurethane foam has good thermal insulating property, impact of frost heaving on the derrick foundation can be reduced effectively, and safety and reliability of a permanent derrick are guaranteed.

Description

technical field [0001] The invention relates to a construction method for reducing the effect of frost heaving on a derrick foundation, and belongs to the technical field of derrick foundations. Background technique [0002] At present, the artificial freezing method is mostly used in the construction of coal mines. In order to shorten the construction period as much as possible and ensure that the freezing wall has sufficient strength, multi-ring holes are often used for freezing, that is, the main (auxiliary) freezing holes and anti-slab holes are arranged. Therefore, when the net diameter of the wellbore is large, the layout of the freezing holes often conflicts with the derrick foundation of the permanent derrick. When the design position of the foundation conflicts with the position of the frozen pipe, the opening position of the frozen pipe should be moved under the premise of ensuring the intersection of the frozen wall. However, the frozen pipes near the foundation ...

AI Technical Summary

Problems solved by technology

However, the improvement of foundation soil is only limited to foundations of limited depth and cast-in-place piles, and has little effect on cast-in-place piles in deeper positions; the circle diameter of the frozen hole layout is reduced, and the distance between the frozen hole and the derrick foundation is increased, while the freezing period of the frozen shaft in the current design If it is longer, the freezing front will still develop to the position of the derrick foundation and cast-in-place pile and cause obvious uplift and deformation; arrange temperature-insulating holes near the derrick foundation, and circulate normal temperature water or hot water in the hole, which can take away the cold released by the freezing pipe in time. Therefore, it can meet the freezing requirements of the derrick foundation and its cast-in-situ piles, but the investment is large and a large amount of energy loss is caused

Images