Loess collapsibility evaluation and calculating method

Abstract

The invention discloses a loess collapsibility evaluation and calculating method. A stress-strain (collapse deformation) curve of soaked loess is calculated according to the results of bore water injection lateral loading test; collapse start pressure of the loess is determined according to the curve; collapsibility of the loess is judged by comparing stress value of foundation soil deeply soakedto certain depth and the collapse start pressure value, so that (self-weight) collapse bottom boundary of the loess can be determined; the collapse bottom boundary may serve as a maximum dept to treata collapsible loess foundation; the (self-weight) collapse boundary is important basis to determine a foundation treatment depth and may also serve as a neutral point depth for a pile foundation; modulus of a certain stress segment can be calculated according to the post-soaking stress-strain curve of the loess; collapsibility of the loess can be calculated according to the modulus. The loess collapsibility evaluation and calculating method is provided as a new way to calculate loess (self-weight) collapsibility.

Description

technical field [0001] The invention relates to the technical field of construction engineering, in particular to an evaluation and calculation method for the collapsibility of loess, which can be used for the collapsible bottom boundary, initial pressure of collapsibility, depth of the neutral point of pile foundation and loess Determination of collapsibility. Background technique [0002] Loess is widely distributed in my country. Loess in many areas not only has collapsibility, but also has self-weight collapsibility. The area and thickness of self-weight collapsible loess in Northwest my country and North China are relatively large, and the large thickness self-weight wet The evaluation and treatment of sunken loess is a difficult problem in engineering. At present, the collapsibility of loess can be calculated by immersion load test, field test pit immersion test and indoor test. The immersion load test and field test pit immersion test have high precision, but the inv...

AI Technical Summary

Problems solved by technology

The immersion load test and field test pit immersion test have high precision, but the investment and cost are relatively large, and the test period is long, so it is not suitable to be widely used in engineering

The method often used in engineering is to carry out the indoor test method stipulated in the current "Code for Buildings in Collapsible Loess Areas" (GB50025-2004). The stress state is quite different, and the correction coefficient changes too much during the calculation. The determined collapsible bottom boundary, the position of the neutral point of the pile foundation, and the collapsible amount are all quite different from the results of the field immersion test, and the test process relatively complex

Images