Pile foundation project of Liubei converter station project civil construction lot A is located in Luzhai County, Guangxi, invested by China Southern Power Grid. In total, the project has completed 565 reinforced concrete piles with a diameter of 800mm and 3,952 m³ of karst treatment.
The construction site of the project is strongly developed karst, caverns are mostly developed below the bedrock surface, and the upper part of the bedrock surface joints and fissures are developed, and it is very easy to break through the rock surface and cause slurry leakage in the process of punching. According to the situation of advance drilling, for the serious slurry leakage phenomenon in the foundation pile holes, the construction adopts the method of " pouring C15 concrete to plug the leakage and forming holes twice" for control. For the existence of unfavorable geological phenomena in the process of drilling causeing the hole slant or can not be drilled normally, the extended core barrel with cutting picks (length 1.8m) is used to drill slowly, when the use of the extended core barrel with cutting picks can not solve the problem, the C15 concrete will be used to pour the hole that has been drilled to 50 cm above the problematic part, wait for 24h ~ 48h to re-drill, effectively solving the case of the hole slanting that can not be drilled.
The pile foundation project of Liubei converter station project civil construction lot A started on January 4, 2019, and was completed on May 6, 2019. During the construction process, the project team overcame the difficulties of continuous rainy weather in the local area, poor access roads and complex geological conditions to successfully complete the construction task. After third-party testing, the results were all qualified which was highly praised by the owner and the general contractor.
