Composite pile structure suitable for coastal deep reclaimed soil foundation treatment and construction method

Abstract

The invention discloses a composite pile structure and a construction method suitable for treating deep and thick coastal dredging and filling soil foundations. The structure includes a prestressed concrete thin-walled hollow square pile, a nail-type two-way mixing powder spray pile and an upper cushion layer. The prestressed concrete thin-walled hollow square pile is a long rigid pile, which passes through the dredging fill layer to the bearing layer to control settlement. At the same time, a reinforced concrete cap is set on the top of the prestressed concrete thin-walled hollow square pile for Adjust the pile-soil load sharing ratio to give full play to the high bearing capacity of the prestressed concrete thin-walled hollow square pile; the nail-shaped two-way mixing powder-sprayed pile is a flexible pile, based on the principle of stress transfer and load-bearing optimization of the composite foundation, focusing on strengthening the upper part with large additional stress The soft soil layer is dredged and filled to improve the replacement rate of the upper pile body; the prestressed concrete thin-walled hollow square piles and nail-shaped two-way mixing powder spray piles are arranged alternately, which can not only meet the requirements of bearing capacity and post-construction settlement, but also save project cost .

Description

technical field [0001] The invention relates to a composite pile structure and a construction method suitable for foundation treatment of deep and thick dredging fill soil along the coast. Background technique [0002] my country has a coastline of 18,000km, and there are 12 provinces, municipalities, and autonomous regions along the coast, including Liaoning, Hebei, Tianjin, Shandong, Jiangsu, Shanghai, Zhejiang, Fujian, Taiwan, Guangdong, Guangxi, and Hainan. The tidal flats are well developed and have great potential for development. At the same time, with the rapid development of the economic construction of my country's coastal cities, the population of coastal areas is increasing, and the demand for land is also increasing, and the use of coastal intertidal zone silt flat land reclamation is to alleviate the shortage of land resources. effective way. According to preliminary statistics, since the founding of New China, my country has reclaimed about 12,000 hectares of ...

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Problems solved by technology

[0004] For dredger filled soil foundation, in order to meet the requirements of foundation bearing capacity and deformation control, surcharge preloading method, vacuum combined surcharge preloading method, dynamic compaction method, cement mixing pile, compacted gravel pile, prefabricated pipe Pile, low-strength pile composite foundation method, etc. These construction methods all play a certain role in dredging and filling soil foundation, but they all have their scope of application and have certain limitations.

The surcharge preload is limited by the construction period, the deep cement-soil mixed pile is limited by the depth of mixing treatment and post-construction settlement, and the prestressed reinforced concrete pipe pile is susceptible to the negative friction of the pile side induced by the foundation settlement in the later period, resulting in a decrease in bearing capacity , and is limited by its engineering cost, so the commonly used foundation treatment methods cannot meet the requirements of bearing capacity, deformation control and cost saving at the same time

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