Construction method of in-tube grouting, extrusion and expansion root-fixed pile

Abstract

The invention relates to the technical field of geotechnical engineering and discloses a construction method of an in-tube grouting, extrusion and expansion root-fixed pile. The construction method comprises the following steps of: (1) at the position of the pile, taking away soil by using a drilling machine to form a guide hole; (2) drilling into the bottom elevation position of the guide hole byusing the drilling machine, and pumping grouting material into the guide hole and simultaneously lifting the drilling machine in the pumping process; and (3) implanting a precast pile into the guidehole and pressing the precast pile to the bottom elevation position of the pile, wherein the distance from the bottom elevation of the precast pile to the bottom elevation of the guide hole is smallerthan or equal to 1 / 10 of the depth of the grouting material in the guide hole; the pile end of the precast pile is fixedly connected with a closed type pile tip; when the precast pile is pressed to the bottom elevation of the pile, and a part of the grouting material in the guide hole is extruded into the surrounding soil body at the bottom of the guide hole so as to form a pile end root fixed body. The construction method provided by the invention can increase the bearing capacity of the pile end; the bearing capacity of the pile end is increased by more than 40% in comparison with the bearing capacity of a cast-in-place bored pile with the same diameter; and meanwhile, the compression bearing capacity and the pressure uplift bearing capacity of the pile body can also be increased.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering, and in particular relates to a construction method for grouting in pipes to squeeze and expand root-fixed piles. Background technique [0002] With the development of the construction industry, the scale of the building is increasing day by day, and the additional load on the foundation is increasing. For some high-rise and super high-rise buildings, the natural foundation and composite foundation can no longer meet the requirements of the foundation bearing capacity. Under this condition, the pile foundation It is a commonly used basic form. For some areas where the engineering property of the upper soil layer of the pile foundation is better than that of the lower soil layer of the pile body, the pile foundation generally adopts increasing the pile length to penetrate the weak layer or increasing the pile diameter to increase the lateral resistance to ensure the bearing capacit...

AI Technical Summary

Problems solved by technology

Although the above-mentioned technology has been widely used, there are still the following problems: 1) concrete pouring piles generally have a circular cross-section, which consumes more concrete than the circular cross-section of prefabricated piles; 2) the construction process of concrete pouring piles must be uninterrupted Pour concrete, otherwise there is a risk of pile breakage; 3) The on-site concrete pouring period is long, and the concrete strength has high requirements on age; 4) Due to the existence of pile bottom sediment and pile side mud skin, the end resistance of bored piles, The lateral resistance is affected to a certain extent, which reduces the vertical bearing capacity of the pile

The above process still has the following problems: 1) The conventional prefabricated pile foundation is a soil-squeezing pile, which greatly disturbs the surrounding soil during construction, which has an impact on the prefabricated pile foundation that has been constructed. In severe cases, the constructed pile foundation may be crushed; 2) Due to the uncertainty of the ground conditions, it is more likely that the prefabricated pile sinking cannot reach the designed pile sinking depth; 3) The noise of the hammering pile sinking is relatively large, which will affect the surrounding environment; 4) Conventional prefabricated piles Post-grouting construction process without foundation

Images