Construction method for root-type foundation anchorage and bored, root-type cast in-situ pile with anchor bolts

Abstract

The invention discloses a construction method for rooted foundation anchorage, comprising the following steps:precasting a concrete caisson in sections, excavate or bore hole for the caisson sinking, reserving holes for projection of anchor roots in the wall of caisson;cleaning the bottom of the bore hole, and sealing the bottom with concrete; precasting the beam type concrete roots and, within the bore hole, projecting the roots into the earth around the caisson;sealing a concrete cover over the bore hole to form a flat cap, which can be used as the cap of a bridge foundation.The invention also discloses a construction method for a root-type cast in-situ bored pile with anchor roots, comprising the following steps:placing a reinforcement cage in a bored hole; each guide framework is internally provided with anchor roots;using a vibration extruder to squeeze the roots in the reinforcement cage;using the squeezing head of the vibration extruder to squeeze the anchor roots from top to bottom gradually. The invention greatly improves the traditional foundation structure. The anchor roots increases friction and structural stability greatly, thus making it possible to reduce gravity of the structure.

Description

FIELD OF THE INVENTION[0001]The invention relates to a foundation construction method for civil engineering, bridge construction and hydraulic structure, in particular to a construction method for root type caisson foundation.BACKGROUND OF THE INVENTION[0002]At present, foundations in common use in engineering construction at home and abroad comprising: pile foundation, cylinder pile foundation, open caisson foundation and underground diaphragm wall foundation.[0003]The pile foundation refers to a foundation composed of a group of piles jacked or sunk into the soil and a cap connecting the pile top. External force is distributed on various pile heads via the cap, and then transmitted into surrounding soil and deep soil below the pile toe via the pile shaft and the pile toe. The pile foundation, suitable for deep soil, has the advantages of the lightest structure, higher degree of mechanization of construction and faster construction progress among all deep foundations, being a relat...

AI Technical Summary

Benefits of technology

The invention is a new type of foundation called root type caisson foundation, which is designed to improve the stability and bearing capacity of bridge foundations. It is simple to construct, uses less material, and can be safely and reliably performed. The root type caisson foundation is made up of a rigid body, a flexible beam, and the soil where it is placed. It breaks through traditional methods of frictional resistance between the soil and the foundation, making it easier to construct and control the quality of construction. Overall, the invention optimizes traditional foundation structures, increases stability, and reduces structural gravity, making it more economical and useful for both hydraulic and large-scale structures.

Problems solved by technology

For example, hammering the precast pile causes noise pollution, demanding for more reinforcing steel bars, thus leading to higher cost of construction.

The common cast-in-place pile has the disadvantages of greater consumption of reinforcing steel bars and cement, intractable disposing of uncompacted soil on the pile toe and possible contraction of the pile shaft.

The tube-sinking cast-in-situ pile also has the disadvantages of noise pollution, quality problem of the pile shaft, lower bearing capacity and frequent prone to occur accidents.

The tube caisson foundation is only suitable for riverbeds without overburdens or with thick overburdens, unsuitable for regions with geological defects.

However, the open caisson foundation has a longer construction time and is demanding for construction technology; furthermore, the open caisson is prone to incline or sink resulted from quick sand in construction.

The underground diaphragm wall foundation is difficult for construction under special geological conditions (for example, soft mucky soil, alluvium containing boulder and super-hard rock etc.), and is prone to misalignment of adjacent wall sections and water leakage in case of improper construction method.

In addition, compared with other construction methods, the underground diaphragm wall foundation has higher construction cost in case of serving as a temporary retaining structure.

Besides, mud disposal is quite troublesome for construction in cities.

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