Low back pressure saturation method for loess liquidation experiment

Abstract

The invention discloses a low back pressure saturation method for loess liquidation experiment. The method comprises the following steps: preparing an original or remolded loess test sample; mounting an experiment device; checking the experiment device; preheating the experiment device for more than 20 minutes; mounting the test sample; charging water into a pressure chamber, subsequently adjusting the confining pressure and the back pressure to be zero, zeroing the pore water pressure and the volume change, and finally adjusting the initial shaft pressure to be zero; initializing the confining pressure and the back pressure, and after the confining pressure and the back pressure are stabilized, gradually exerting the confining pressure and the back pressure in sequence step by step. The method adopts the loess test sample which is saturated by using a low back pressure saturation method, the saturability is greater than about 95%, the reproducibility of the experiment is remarkably improved when being compared with that of water head saturation, the analysis on the original loess micro structure before and after the back pressure saturation shows that the horizontal and vertical structure of the test sample is generally complete when the low back pressure saturation method is adopted, the result shows that under the low back pressure condition, the saturability can be improved by using the method, the structure of the test sample is not damaged, and the method has the characteristics of high saturability, relatively high control precision and the like.

Description

technical field [0001] The invention belongs to the field of geotechnical test research, in particular to a low back pressure saturation method for loess liquefaction test. Background technique [0002] With the inclination of the national development policy, the loess area has become the main area for development, and most of the loess areas are located in high-intensity earthquake areas. Recent investigations on earthquake cases and laboratory experiments show that saturated loess and even loess with high water content also have high liquefaction potential and flow damage potential. , the affected area is large and most of them are destructive. The potential reality of saturated loess liquefaction earthquake damage and the situation of rapid economic development put forward requirements for strengthening the research on earthquake liquefaction hazards and anti-liquefaction measures of loess. [0003] At present, certain achievements have been made in the study of the sat...

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Problems solved by technology

[0004] (1) The saturation time is too long, and the sample will be damaged by collapsing when it is immersed in water for a long time;

[0005] (2) The saturation is low. Due to the residual air in the micropores of the loess during saturation, the soil saturation is low

In addition, most of the current loess liquefaction methods directly refer to the saturation method in the relevant domestic and foreign specifications, without considering its applicability in the saturation process of the loess liquefaction test

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