水运工程2024,Issue(12) :238-244.

水下DCM法加固软基关键参数优化

Optimization on key parameters of soft foundation reinforcement by underwater DCM

汪海洋
水运工程2024,Issue(12) :238-244.

水下DCM法加固软基关键参数优化

Optimization on key parameters of soft foundation reinforcement by underwater DCM

汪海洋1
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作者信息

  • 1. 中交四航工程研究院有限公司,广东 广州 510230;中交交通基础工程环保与安全重点实验室,广东 广州 510230;南方海洋科学与工程广东省实验室(珠海),广东 珠海 519000
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摘要

陆上和水下软基深层水泥搅拌桩施工参数通常通过试桩确定,水下DCM多为四轴,施工参数难以确定.以某填海工程DCM桩为背景,对水下DCM桩进行试桩,对水泥搅拌桩搅拌切土次数、底部W施工曲线、喷浆工艺等关键参数进行研究,并通过三重管取芯对水泥土强度进行检测.结果表明,淤泥中水泥掺量由 320 kg/m3 优化为 300 kg/m3,固化 28 d水泥土搅拌桩无侧限抗压强度大于 1.0 MPa,满足设计要求.底部硬黏土层增加 2 个小W施工曲线进行复搅可以提高水泥桩的强度.为充分将黏土搅散,下贯速度不宜大于0.3 m/min,提升速度不宜大于1.0 m/min.搅拌叶片的旋转速度应与钻头下贯或提升速度匹配,以提高搅拌效果,进而提高成桩质量.

Abstract

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.

关键词

深层水泥搅拌法/软基/施工参数/无侧限抗压强度

Key words

deep dement mixing/soft foundation/construction parameter/unconfined compressive strength

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出版年

2024
水运工程
中交水运规划设计院有限公司

水运工程

CSTPCD
影响因子:0.428
ISSN:1002-4972
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