Retaining Wall
2021
SANCHONGSHAN - China
YunNan JinDing Zinc Industry Co.,Ltd
YunNan JinDing Zinc Industry Co.,Ltd
KunMing Nonferrous Metallurgy Design and Research Institute
LANPING LEAD-ZINC MINING SANCHONGSHAN DUMP RETAINING WALL PROJECT
In construction
In construction
Problem
LanPing County is very rich in mineral resources, mainly non-ferrous metal minerals. It enjoys the reputation of Hometown of Non-ferrous Metals in Yunnan and Pearl of the Plateau in Northwest Yunnan. It is a key mining area on the SanJiang Metallogenic Belt.
The proposed dump site is located in the sub-stable area of the crust. There is no Holocene active fault passing through the site, and there is no seismogenic fault within 10km of the site. The adverse geological effects are generally developed. The proposed dump is basically stable under the current situation. There are no unfavorable geological phenomena such as subsidence caused by tunnels left over from history and goafs in the mine, and it is suitable for capacity expansion.
In order to ensure the smooth implementation of open-pit mining, considering various factors such as waste rock transportation, land acquisition and relocation, safety measures, etc., after multi-level grading of the dump site with a height of more than 100 meters, it is necessary to set up a slag dam at the bottom to avoid occupying the ground. To the boundary of the lower refractory ore storage yard and to further ensure the stability of the entire dump. If the slope of the high fill dump cannot be supported in a timely and effective manner, the risk of collapse is likely to exist. Therefore, the owner urgently needs to find a technically feasible, safe and economical blocking solution.
Solution
According to the geological conditions and engineering requirements of the project, the owner and the design unit comprehensively consider the economy and the overall force of the retaining wall, and finally decide to adopt the reinforced Gabion retaining wall scheme.
- The reinforced gabion slag dam is composed of reinforced gabion and geogrid. The main reinforcement of the reinforced soil adopts a high-strength fiber-plastic grid of 150~200KN/m. The reinforced gabion adopts galvanized and high wear-resistant organic coating double-stranded hexagonal metal mesh as the face wall, and the inside of the face wall is filled with stone, and the stone part comes from the waste stone after the excavation of the slope; the structural fill is also made of The waste soil, gravel and other materials are taken locally, which saves the project cost to a large extent.
- The maximum design height of the retaining wall of the slag dam is 30m, the slope body is used reinforced with fiber-plastic grilles. The length of the reinforcement in the dam body is determined by the top width of the reinforced Gabin slag dam of 5m, the bottom width of 53m and the slope ratio of the inside and outside of the dam body. Since the bottom 4m is buried underground, in order to reduce the cost , the wall to cancel the reinforcement gabion.
- Because the foundation trench is deep, the bank slope is high, the terrain is steep, and the physical and mechanical indicators of the stratum are low, the bank slopes on both sides need to be excavated in steps. Sandstone, so that the bearing capacity of the foundation meets the requirements.