This project is located in Huizhou City, Guangdong Province, entrusted by CNOOC Huizhou Petrochemical Company Limited, our company was responsible for the construction of grouting piles of this project. The project started on September 28, 2020 and completed on June 14, 2021, with a total of 2,644 piles, including 328 piles of 1,000mm diameter, 1,081 piles of 800mm diameter and 1,235 piles of 600mm diameter.
According to the design parameters of the construction area and the site survey and ground investigation data, combined with the experience of similar projects and the requirements of the owner, the project adopted rotary drilling rig to drill holes. The pile length of piles with a diameter of 800mm is mainly determined by entering ⑤3 layer of moderately weathered mudstone not less than 2.0m, the pile length of piles with a diameter of 1，000mm is mainly determined by entering ⑤3 layer of moderately weathered mudstone not less than 2.5m, and the pile length of piles with a diameter of 600mm is mainly determined by entering ⑤ layer of strongly weathered or fully weathered mudstone. Mainly with ⑤3 layer of medium weathering mudstone with higher strength and better integrity as the bearing layer, larger rotary drilling rigs with a torque of not less than 240KN.m was used, bentonite mud was used for the slurry, the reinforcement cage was connected by lap welding, and the grouting was done by conduit grouting method.
In the construction process, in view of the problems that there are many construction parts and the shallow backfill is mixed with large stones, which is easy to lead to pile position deviation, we adopt the system of "three-level inspection, one-level approval and one-level acceptance" and check the pile casing embedding deviation one by one. The empty piles in several parts are deeper, and after the concrete filling is completed, the concrete surface will drop after the shoring is pulled up. During the concrete pouring process, the engineer on duty is responsible for checking the quantity of concrete pouring and checking the height of pile top, and strictly controlling the pouring quantity to ensure that it meets the standard requirements.
After the end of the project, the owner entrusted a third-party pile foundation testing unit to conduct the test, through the vertical static load test, high strain and low strain test, the test results are all qualified, no III or IV piles occur, and the quality inspection results meet the national norms, design requirements and contract quality requirements, and the pass rate is 100%.
