Non destructive detection method of anchor rod ultimate bearing capacity

Abstract

A method for nondestructively detecting the maximum bearing capacity of rock bolt includes applying dynamic measuring technique to obtain information and applying intelligent signal analysis technique to process obtained information, then applying trained neural network intelligent identification system to predict the maximum bearing capacity of rock bolt.

Description

technical field [0001] The invention relates to a non-destructive testing method for the ultimate bearing capacity of a bolt. Background technique [0002] Bolt anchoring engineering technology is an important field of geotechnical engineering. Due to the long-term harsh geological environment, the anchoring system is easily affected by erosion and natural disasters and has quality problems. Once an accident occurs, it will endanger people's lives and property. , and cause huge economic losses. Since the 1960s in our country, a large number of anchor rods have been used in various engineering designs, many anchor cables have been used after the 1970s, and more soil nails have been used in the 1990s. Their total will be in the hundreds of millions. The advancement, reliability, and economy of these anchor rods, anchor cables, and soil nails are beyond doubt, but how long is their service life in countless projects used as permanent support? If it fails, it will become a hi...

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Problems solved by technology

However, the tension load is converted by the piston area of ​​the jack and the pressure of the oil pump. As for the anchoring force after locking and the change in long-term operation, it cannot be evaluated. In addition, it is not only time-consuming to measure a complete load-displacement curve, It is costly (at present, 5% of the samples need to be taken out for destructive testing in the ordinary anchor bolt drawing test, and the average cost of each bolt is as high as 500 yuan. In my country, the annual consumption of anchor bolts in mine shaft and roadway projects is as long as more than 1700km, according to Calculated at an average distance of 3 meters between bolts, the total amount of bolts used is 561,000 bolts. If the random inspection rate is 5%, 28,100 bolts need to be inspected randomly. Calculated at 500 yuan per bolt, only one item of random inspection will cost 14.02 million yuan per year. Based on the average inspection time of each anchor rod of 3 hours, it will take 84,150 hours; the current national inspection standard - sampling inspection rate is only 5%, because the detection area is small, it is difficult to represent the actual situation of the anchor rods in the entire anchoring system

[0004] In short, the current detection method for the bolt system is still in the traditional method, which cannot meet the requirements of large-scale engineering construction. Therefore, the research on the technology of non-destructive detection of the ultimate bearing capacity of bolts has always been a major key to the construction of transportation, municipal and other projects. one of the techniques

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