Combined rock-embedding pile and its construction method

Abstract

A combined pile embedded in rock is constructed through prefabricating reinforced concrete pipe or other pile with reinforcing bars used as the load bearing member in soil layer, embedding the reinforced concrete member or steel member with reinforcing bars in the drilled hole in rock, and grouting in-situ. At least one group of reinforcing bars passes through said member and cast inside it for bearing pressure or pull and improving the integrity of whole pile. Its advantages are high load-bearing power, simple structure and low cost.

Description

technical field [0001] The invention relates to a pile used as a deep foundation of a building, in particular to a combined pile which relies on the bonding force between grouting material, prefabricated pile and the inner wall of a rock hole to gradually spread the load to the bearing rock layer along the vertical direction and its construction method. Background technique [0002] The prefabricated piles used in the foundation of buildings have always been connected one by one by a pile driver on site with prefabricated reinforced concrete piles or section steel piles, and the soil is squeezed into the design depth. The bearing capacity of the force layer is used to support the pile head load, such as US patent US 4,199,277. The disadvantages of this method are: first, the construction noise is large and the vibration is severe; second, the pile body is easily damaged or weakened under the violent and continuous impact of the piling hammer; The ability is poor. When some ...

AI Technical Summary

Problems solved by technology

The disadvantages of this method are: first, the construction noise is large and the vibration is severe; second, the pile body is easily damaged or weakened under the violent and continuous impact of the piling hammer; The ability is poor. When some piles of the foundation have to be located on the local hard soil layer, it is easy to cause uneven settlement and inclination of the building. Fourth, the deeper the bearing layer, the greater the energy of the pile hammer required, which will give the piling machine The production of

Construction costs also increase accordingly

[0005] 2. As the grouting material of the protective layer, it may have to face loose soil layer and groundwater before hardening, and there is no steel skeleton in it, so the construction quality is easily affected by the speed of pulling out the temporary casing, the soil quality and the flow of groundwater. Quality problems such as necking, voids and sediment interlayers

[0006] In the design of some composite piles, although prefabricated piles and cast-in-place concrete parts are also included, their bearing mechanism is still the same as that of traditional bored piles, that is, the load is transmitted by the local pressure of the pile bottom and the contact level of the rock. Typical end-on piles are only partly replaced by prefabricated concrete piles, see JP-127054, it is always difficult to avoid the influence of sediment on the quality of piles

Because the strength of concrete is usually greater than that of rock, if the full bearing capacity of the pile body is to be exerted, the bottom must be expanded, and the cost of the machinery used for bottom expansion is high, the operation technology requirements are high, and pipe sticking accidents are prone to occur, the actual bottom expansion size also difficult to control

The positioning of the prefabricated pile sections was also very difficult as there were no reinforcements extending straight to the rock face

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