I. Introduction. CFG pile is the abbreviation of cement fly ash gravel pile, which is made of cement, fly ash, gravel, stone chips and a small amount of sand, which has good bonding properties and strong mechanical properties, and is widely used in soft soil foundation treatment. This article will introduce the Yunmeng CFG pile construction plan, including construction preparation, construction technology, quality control and other aspects.
2. Preparation for construction.
1.Site investigation: Before the construction of CFG piles, it is necessary to survey the site, understand the geological conditions, and determine the pile layout and pile length. At the same time, it is also necessary to investigate the surrounding buildings and underground pipelines and take protective measures.
2.Construction materials: Select CFG pile materials that meet the requirements, including cement, fly ash, gravel, stone chips, etc., to ensure that the quality is qualified.
3.Machinery and equipment: Select the appropriate CFG pile construction machinery and equipment according to the construction requirements, and carry out debugging and inspection to ensure the smooth progress of the construction.
4.Technical disclosure: Before construction, it is necessary to make a technical disclosure to the construction personnel, and clarify the construction requirements, process flow, safety precautions, etc.
Third, the construction process.
1.Measurement lofting: Carry out pile lofting according to the design drawings, determine the position of the pile position, and mark it with obvious marks.
2.Rig in place: Move the CFG pile rig to the designated position and adjust the verticality of the drill pipe to ensure that the drill pipe is perpendicular to the ground.
3.Drilling: Start the drilling rig, the drilling depth should meet the design requirements, and pay attention to controlling the drilling speed to ensure the quality of the pile foundation.
4.Mixing mixture: Mix cement, fly ash, gravel, stone chips and other raw materials into a mixture in proportion and stir evenly.
5.Filling mixture: The stirred mixture is poured into the borehole through the pipeline, and the vibration tamping is carried out at the same time to ensure that the compactness of the mixture meets the requirements.
6.Extubation: After pouring the mixture, the drill pipe is pulled out to form a CFG pile. In the process of extubation, it is necessary to pay attention to controlling the extubation speed to avoid affecting the quality of the pile foundation.
7.Pile head treatment: After the extubation is completed, the pile head needs to be trimmed to ensure that the flatness of the pile head meets the requirements.
8.Quality inspection: During and after the construction is completed, quality inspection is required, including pile length, mixture mixing ratio, density, etc., to ensure that the construction quality of CFG piles meets the requirements.
Fourth, quality control.
1.Control the quality and proportion of raw materials in strict accordance with the design requirements to ensure the quality of the mixture.
2.Ensure that the drilling depth and verticality meet the requirements to avoid affecting the quality of the pile foundation.
3.When pouring the mixture, it is necessary to pay attention to controlling the extubation speed and time to avoid the phenomenon that the mixture is not dense or the necking is formed.
4.During the construction process and after the construction is completed, it is necessary to regularly inspect the quality of the CFG pile, and deal with the problems in time.
5.Do a good job of drainage work on the construction site to avoid water accumulation affecting the quality of construction.
6.Do a good job of safety protection measures to ensure the safety of construction personnel.
V. Conclusion. CFG pile is a commonly used soft soil foundation treatment method, through reasonable construction preparation, construction technology and quality control measures, the construction quality of CFG pile can be guaranteed, and the treatment effect of soft soil foundation can be improved. In the construction of CFG piles in Yunmeng area, it is necessary to carry out survey, material selection, equipment selection and other preparations according to the actual situation of the site, and operate in strict accordance with the construction plan to ensure that the construction quality meets the design requirements.