Abstract
An inclined goaf caused by storage mining is a serious risk to subgrades and pavements. In this paper, effective investigation and detection methods of goafs were discussed considering the project of the Urumqi East Ring Expressway crossing the existing goaf of Zhongxing no. 2 mine. Moreover, by theoretical analysis and a series of field comparative tests, reasonable grouting parameters and the treatment plan were obtained. By comparing the test results of the field and laboratory, the influence of groundwater on the effect of grouting was revealed to reduce the compressive strength of the consolidating objects of the slurry. The high-density resistivity method presented strong anti-interference ability and high accuracy in a depth range of less than 150 m in the investigation of the goaf. The results of the treatment showed that it is necessary to conduct research and analysis from multiple aspects to obtain the best treatment plan of a goaf and ensure the safety of a project.
Highlights
In recent years, with the development of the highway network in China, many highways inevitably cross goafs
A cement fly ash slurry was formed of water, cement, and fly ash in different proportions (1 : 0.2 : 0.8, 1 : 0.22 : 0.88, 1 : 0.24 : 0.96, and 1 : 0.26 : 1.04), as shown in Figures 10 and 11. e properties considered in the tests included the viscosity of the slurry, setting time, rate of consolidation, compressive strength of the consolidating objects of the slurry, and influence of water glass on the slurry. e test results showed that when the cement fly ash slurry is used, its water-solid ratio should be between 1 : 1.1 and 1 : 1.3, with the cement accounting for 20% of the solid phase
2 Groundwater in a goaf has a great impact on the compressive strength of the consolidating objects
Summary
With the development of the highway network in China, many highways inevitably cross goafs. Under the influence of downhole winds and groundwater, coal pillars are continuously weathered and stripped, and their supporting function is continuously weakened At this time, the roof may be deformed and spalled, causing the problem of settlement. Foreign and national scholars and engineers have conducted relevant researches on the problems of goafs and have achieved many results in the field of scientific research and construction. Some scholars have performed numerous field tests using geophysical exploration methods; there are few studies on the effect of the application of geophysical exploration results in the grouting process. Most of the Advances in Civil Engineering research is limited to either investigation, theoretical analysis, treatment measures, or detection of project quality. The Urumqi East Ring Expressway crossing the existing goaf of Zhongxing no. 2 mine was considered, and the comprehensive treatment technology of the goaf was systematically studied. e results are of great significance for reducing the project cost, improving the quality of the highway construction, and ensuring the safe operation of the highway
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
