Optimization on key parameters of soft foundation reinforcement by underwater DCM
The construction parameters of deep cement mixing(DCM)on land and underwater soft foundation are usually determined by test pile,and the underwater DCM is mostly four-axis,so the construction parameters are difficult to determine.In this paper,the DCM piles in reclamation project is studied,the key parameters of the cement mixing pile,such as BRN,W-shaped construction curve at the bottom and cement slurry jet technology are studied,and the cement soil-cement strength is tested through triple tube coring.The results indicate that the cement content in the silt is optimized from 320 kg/m3 to 300 kg/m3,and the unconfined compressive strength of the cement-soil mixing pile is greater than 1.0 MPa after 28 days curing,which meets the design requirements.The pile's strength can be improved by adding two W-shaped curve to remix the hard clay layer at the bottom.To fully stir the clay,the penetration speed should not be greater than 0.3 m/min and the withdraw speed should not be greater than 1.0 m/min.The stirring blade rotation speed should match the drill penetration or withdrawing speed to improve the mixing effect and the quality of pile.
deep dement mixingsoft foundationconstruction parameterunconfined compressive strength
万方数据
维普
