Novel construction method of large-diameter composite structure pile consolidated foundation

Abstract

The invention discloses a novel construction method of a large-diameter composite structure pile consolidated foundation. The construction method is applicable to the consolidation of deep and weak foundations under "various complicated geological conditions and especially in the absence of bearing layers or bearing interlayers"; the construction method comprises the following steps: firstly, analyzing the foundation conditions of a region for construction to determine layer category partition of weak soil layers in the region and physical and mechanical properties of various layers; subsequently, carrying out targeted construction scheme design, and then driving a consolidation pile composed of an inner-layer pile body, a middle-layer meshed cylinder and an outer-layer water-permeable geomembrane into the region for construction until the bottom end of the consolidation pile extends into the weak foundation by not less than 10m; after the construction of the consolidation pile is finished, forming by pouring a pile cap at the top end of the consolidation pile, laying a composite spacer and carrying out subgrade filling, and finally, carrying out the construction of an upper structure layer. The novel construction method is applicable to solve the consolidation problems of deep and weak soil foundations under various complicated difficult conditions and especially in the severe absence of bearing layers, and further has the advantages of less number of pile bodies, shorter consolidation period, faster construction progress and lower construction cost.

Description

technical field [0001] The invention relates to the technical field of soft soil foundation reinforcement, in particular to a construction method for foundation reinforcement with a novel large-diameter composite structure pile. Background technique [0002] At present, the reinforcement of soft soil foundations includes the newly built and rebuilt passenger and freight railways, urban railways, intercity railways, high-speed railways, urban rail transit and other rail traffic, highways, expressways, municipal roads and other road traffic, and airports, ports, etc. Reinforce the soft soil foundation of large-scale site projects such as docks, logistics bases, power stations, comprehensive transportation hubs, underground deep foundation pit projects, and wetland landscape reconstruction. [0003] Traditional soft soil foundation reinforcement treatment methods or functions are relatively single, and can be roughly divided into two categories in terms of approaches and method...

AI Technical Summary

Problems solved by technology

[0003] Traditional soft soil foundation reinforcement treatment methods or functions are relatively single, and can be roughly divided into two categories in terms of approaches and methods: one is drainage consolidation methods, such as bagged sand wells, plastic drainage boards and other passive drainage consolidation methods Active drainage consolidation methods such as vacuum preloading and vacuum preloading, these technical means are very limited in improving the bearing capacity of the foundation and controlling the settlement. They are only suitable for relatively shallow layers and have low requirements for the bearing capacity of the composite foundation, especially for settlement control. Reinforcement of soft soil foundations with low requirements; the other is to use pile reinforcement methods to form a composite foundation with the soil between piles to improve the comprehensive bearing capacity and settlement control capacity of the foundation. The reinforced piles can be roughly divided into: (1) Low-strength bulk piles or granular piles, such as compacted gravel cushions, compacted gravel piles, gray (cement) soil compacted piles, etc.; (2) flexible piles with medium strength and good integrity, such as cement-soil mixing (3) Semi-rigid and rigid piles with better strength and integrity, such as plain concrete piles, reinforced concrete piles, etc. This kind of pile reinforcement method has quick results, but it needs to rely on additional stress to affect the depth One or more layers of better natural foundation bearing layers within the range

In addition, the known non-drainage pile reinforcement methods all have a relatively prominent weakness: the soil between the piles cannot continue to improve over time, and the reinforcement effect may attenuate in the later stage

Images