Dynamic compaction reinforcing method for improving stability of cast-in-place pile collapse hole

Abstract

The invention relates to a dynamic compaction reinforcing method for improving the stability of a cast-in-place pile collapse hole. The method is characterized by comprising the following steps of 1, measuring relevant parameters and the layer position depth and thickness of a foundation easy collapse hole soil layer; 2, determining the collapse-induced force and the collapse-resistant force of the drilling cast-in-place pile collapse hole layer position; 3, measuring the cohesion force c' and the inner frictional angle phi' between the dynamic compaction reinforcing test experiment and a collapse hole layer; 4, determining the sandy soil layer collapse critical inner frictional angle phi<critical> of a sandy soil layer and the collapse hole instablilty criterion rule; 5, determining the quantitative relationship of the inner frictional angle phi' and the cohesion force c' of a cohesive soil layer, and performing relevant reliability inspection; 6, determining the quantitative relationship of the dynamic compaction parameter and the inner frictional angle phi' of the corresponding collapse hole layer, and performing relevant reliability inspection; 7, determining foundation dynamic compaction collapse-resistant stability reinforcing method and parameters. The method has the advantages that the problem of hole wall stability is effectively solved; in addition, the construction quality of the large-scale drilling cast-in-place pile is ensured; the requirement of the construction period is met; the construction cost is reduced.

Description

technical field [0001] The invention relates to the field of foundation stability evaluation and reinforcement, in particular to a method for measuring and designing dynamic tamping reinforcement for preventing borehole collapse of cast-in-situ piles. [0002] technical background [0003] Pile foundation is one of the main foundation reinforcement projects to increase the overall stability of the foundation and improve the bearing capacity of the foundation. According to the construction method of the pile, it can be divided into soil-squeezing piles, partial soil-squeezing piles and non-squeezing piles. Among them, the bored pile in the non-squeeze pile is widely used because of its high bearing capacity, no soil squeeze, no earthquake damage during construction, low noise and suitable for use in densely built urban areas. However, hole wall stability problems such as hole wall collapse and necking often occur during the construction of bored piles, which often cause pile ...

AI Technical Summary

Problems solved by technology

Although the above three methods can solve the problem of hole wall stability to a certain extent, they also have their own limitations. For example, mechanical analysis methods are often limited to the analysis of hole wall stability at the theoretical level, and no good prevention measures, it is difficult to apply to engineering practice; the calculation process of the numerical analysis method is complicated, and the boundary conditions and constitutive relations of the hole wall soil are relatively strict, and are affected by the geological model, simplified mechanical model and mechanical parameters. It is difficult to make an accurate evaluation, and it is not easy to apply to engineering practice; and the analysis method of engineering experience lacks a theoretical basis, and its analysis method has no unified and clear regulations, so it cannot be widely promoted and applied in the drilling construction of cast-in-situ pile engineering. application

Images