Forming device and construction process for reverse screw pile

Abstract

The invention discloses a forming device and a construction process for reverse screw pile, wherein the forming device comprises a drill rod, a grouting equipment connected with external end of the drill rod and an integrated pipe cap forming device sleeved outside the upper part of the drill rod; the reverse screw pile comprises a pile body and pile ca, the outer wall of the pile body is provided with outer thread structure; the drill rod comprises a core rod and outer thread structure of rod body; the integrated pile cap forming device comprises a support, pile cap forming drill head, rotational drive device and lifting device, the pile cap forming drill head comprises a hollow sleeve and spiral blade; the forming construction process comprises steps of: 1, installing pile cap forming device; 2, drilling hole; 3, lifting and conducting synchronous pile body concrete grouting construction; 4, making the pile cap forming device drill to form clay model; 5, grouting construction of pile cap concrete; 6, forming of reverse screw pile. The forming device has reasonable design, simple construction and good effect, thus can finish construction process of pile body and pile cap of reverse screw pile easily and rapidly.

Description

technical field [0001] The invention belongs to the technical field of pile foundation construction, and in particular relates to a forming device for reverse screw piles and a forming construction process. Background technique [0002] The cast-in-situ pile refers to opening a hole directly on the designed pile position, and its cross section is circular. After the hole is formed, a steel cage is added in the hole and concrete is poured. At present, in foundation projects such as construction, water conservancy, and highways, cast-in-place piles with long spiral holes are widely used due to their advantages of high speed, low noise, no need for mud retaining walls, and low construction costs. But there are following defects and deficiencies in the existing common long spiral hole-forming cast-in-place piles: first, the scope of application is limited, and can only be applied in soil layers such as cohesive soil, silt, and filling soil; When the diameter of the pebble layer...

AI Technical Summary

Problems solved by technology

But there are following defects and deficiencies in the existing common long spiral hole-forming cast-in-place piles: first, the scope of application is limited, and can only be applied in soil layers such as cohesive soil, silt, and filling soil; When the diameter of the pebble layer is large, it is difficult or impossible to drill; therefore, the adaptability of the existing soil layer is insufficient, and some areas cannot be used; second, the vertical bearing capacity of the single pile is relatively poor: the vertical bearing capacity of the single pile is the value of the pile in the pile. The main index in the application of foundation construction, which determines the weight of the superstructure that the pile can bear; the existing cast-in-situ piles are mainly straight rod piles, and the outer surface of the pile body after pile formation is a smooth circumferential surface, and its vertical bearing capacity is The sum of pile side resistance and pile tip resistance; however, after the existing long spiral hole-forming cast-in-situ pile is drilled, the soil at the pile tip is disturbed, which easily forms void soil at the bottom of the hole, reduces the pile tip resistance, and thus affects the bearing capacity of the single pile; 3. The construction progress is slow. The drilled holes formed by long helical drilling are round holes. The threads on the threaded drill rod are mostly forward threads (also called right-handed threads, which refer to threads screwed in clockwise), and the holes are formed During the process, the drill pipes are unearthed continuously, the amount of unearthed is large, the workload of unearthed cleaning and transportation is heavy, and the amount of concrete used is large

[0004] There are the following main problems in the method of using the above-mentioned artificial method for pile cap construction: first, the construction efficiency is low: only 3 to 5 pile caps can be constructed per person per day; second, the cost is high: pure manual production, high labor cost ; Third, the construction quality is uncontrollable: due to the non-standard operation of the construction personnel, the construction quality of the pile cap cannot be effectively guaranteed; fourth, the construction process is complicated and the labor intensity is high; Construction, affecting the construction period of reverse screw piles

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