Static cracking agent radial expansion pressure test method

Abstract

The invention relates to a static cracking agent radial expansion pressure test method. According to the method, a metal material is adopted to make a metal cylinder with a reversed-T-shaped upper end; four measuring points are symmetrically calibrated on the mesa of the cylinder; a radial strain gauge, a tangential strain gauge and a temperature sensor are bonded to each measuring point, whereinthe strain gauges and the temperature sensor are connected with a strain measuring instrument through a wire; the cylinder is filled with a static cracking agent and thereafter is sealed with an upperend cover and a lower end cover; the radial strain and tangential strain of the four measuring points are recorded through an offline and on-line collection mode; after collection is performed for 24hours, and the radial strain and tangential strain measured by the four measuring points are averaged respectively; and maximum average values, together with the outer radius, inner radius, elastic modulus and Poisson's ratio of the metal cylinder, is substituted into a given formula, so that the radial expansion pressure of the static cracking agent is calculated. According to the static cracking agent radial expansion pressure test method of the invention, the mesa of the metal cylinder is adopted to test expansion pressure, the strain gauges can be evenly bonded easily, and therefore, measurement error can be reduced; the temperature of the measuring points is low, so that normal-temperature strain gauges with low cost can be used; and the measured radial expansion pressure used as theexpansion pressure of the static cracking agent at a production site, is more accurate.

Description

technical field [0001] The invention relates to geotechnical engineering technology, in particular to a method for testing the radial expansion pressure of a static breaking agent. Background technique [0002] Static breaker is a kind of high expansion powder cementitious material that can replace explosive blasting to break rock. When the hydration reaction of the static breaking agent occurs in a confined space, it will generate expansion pressure on the wall of the restricted hole, and the maximum expansion pressure can reach 120MPa. Due to the relatively slow hydration reaction process of the expansion agent, the expansion pressure generated during the reaction process can evenly act on the crushed body, and there is no negative blasting effect such as vibration, noise and flying stones during the entire expansion fracturing process. Therefore, static breaking agent rock fracturing technology is widely used in engineering fields such as stone mining, building demolitio...

AI Technical Summary

Problems solved by technology

This method is widely used because of its simple test method, but it has the following defects: ①It is difficult to stick strain gauges on the outer wall of the steel pipe curved surface; The agent will release a lot of heat during the reaction process, which will make the outer surface temperature of the tube body higher after being heated (140-150°C). If the normal temperature strain gauge is used for measurement, the temperature will have a greater impact on the measurement result, resulting in poor measurement accuracy. , if high temperature strain gauges are used, the measurement cost will be increased due to the complicated pasting process of high temperature strain gauges

The static breaking agent expansion pressure testing devices and methods disclosed in these patent documents all belong to testing the axial expansion pressure of the static breaking agent in the confined space. The expansion pressure in the same direction is not the same. The radial expansion pressure of the static breaking agent plays a major role in the production site, and the axial expansion pressure is used as the expansion pressure of the static breaking agent required by the production site. The deviation is large

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