Comprehensive technical research and demonstration project of curtain cutoff in an open-pit mine at Zhani River
1. Introduction
Underground curtain wall technology is used for groundwater closure in Zhani River curtain water cutoff project, in which high-pressure jet grouting pile is used for wall formation in underground cable and high-voltage line areas. However, the stratum structure in this area is complex, the regional stratum is quite different, and the gravel layer is thick, large in grain size, poor in gradation, high in density and has fast groundwater velocity. In addition, there are high-voltage lines, buried optical cables and national highways within the scope of construction.
Layout plan for construction works of the project
2. Solution
The test stage was divided into two months. After various process tests, such as high-pressure jet grouting, high-pressure slurry-retaining jet grouting, static pressure grouting, sleeve valve pipe grouting, large-diameter jet grouting and secant pile, it was finally decided to adopt the MJS high-pressure jet grouting process, RJP high-pressure jet grouting process, Italian soil force high-pressure variable-speed swing grouting process and secant pile (rotary drilling and reverse circulation hole forming) process for construction of piles.
Schematic diagram of wall formed by high-pressure rotary Grouting and high-pressure variable-speed swing jet grouting
Wall section formed by high-pressure rotary grouting and high-pressure variable-speed swing jet grouting
3. Construction Situation
The whole construction lasted 163 days, and 660 jet grouting piles and 456 secant piles were completed. At the same time, many areas which are difficult to be treated by other processes were treated by high-pressure jet grouting, and the length of diaphragm wall is 1457.2m.
On-site construction diagram of high-pressure variable-speed swing jet grouting
Comprehensive technical research and demonstration project of curtain cutoff in open-pit mine at Zhani River
4. Achieved Accomplishment
After the completion of the project, coring inspection was carried out in the construction areas of jet grouting piles and secant piles subject to swing jet grouting. The coring results show that the pile-forming effect was good. The maximum head difference between the inside and the outside of the diaphragm wall exceeded 10.0m, averaging 7m, and will continue to increase, with a remarkable treatment effect.
Through studying and carrying out high-pressure jet grouting pile test under such complicated geological conditions, the jet grouting pressure increased by changing the jet grouting time and filling with additives. In some areas, the problem of high-pressure jet grouting pile formation under certain compactness, large particles and groundwater flow conditions was solved. It has gained valuable experience for the follow-up high-pressure jet grouting construction technology. It has a far-reaching scientific research and engineering significance.
5. FAQ
Q1: What equipment is mainly used for rotary grouting in this project?
In this project, MJS high-pressure rotary grouting equipment imported from Japan, Italian soil ultra-high-pressure variable-speed swing grouting equipment and RJP high-pressure rotary grouting equipment produced by Xi’an Exploratory Machinery Plant are adopted.
Q2: What is the difference between the rotary grouting process of this project and the general high-pressure rotary grouting process?
In this project, the stratum is complex, the gravel layer is thick, the particles are large, and the compactness is high. At the same time, it is difficult to pile under the dynamic influence of groundwater.
Q3: What is the construction cost of jet grouting pile
A: The construction cost of jet grouting pile will depend on many factors, such as geological conditions, stratum compactness, pile diameter and jet grouting depth. Under normal circumstances, a relatively accurate project cost will be provided in the construction quotation.
Hot Tags: mine water hazard prevention technology, China, manufacturers, suppliers, factory, wholesale, price list, buy, for sale,
