浅层软土地基快速动力固结技术.ppt

欢迎各位领导和专家莅临指导WELCOME 浅层软土地基快速动力固结技术Low energy dynamic consolidation combined with light well-point dewatering 同济大学地基基础研究所 Institute of Soil Foundation Tongji University 概述Introduction This method is applicable to sandy soil, sandy silt, miscellaneous fill, etc., the coefficient of permeability of which is relatively high(the coefficient of permeability, ko ,is larger than 10-5). 低能量强夯法结合轻型井点降水施工方案Low energy dynamic consolidation combined with light well-point dewatering 1. 加固效果和工期Reinforcing Effect and Construction period 2．低能量强夯法的加固原理reinforcement mechanism of low energy dynamic consolidation 3．施工方案construction scheme 1）.施工降水dewatering 2）.夯击工艺参数tamping parameters and technique 3）.低能量强夯设备equipment for low energy DCM 4）.收锤参考标准tamping-stop standard 5）.检测和信息化施工monitor and information construction 6）.施工程序和步骤construction procedures and steps 4. 已成功的大面积施工中应用实例case history 1. 加固效果和工效 Reinforcing Effect and Construction Efficiency 加固效果(Reinforcing Effect) In sandy soils, the SPT blow count, N63.5, can reach to 12~15; the CPT value can reach to 5~8Mpa and the PLT bearing capacity to 150~200Kpa. 加固深度(treatment depth) 4-6m 工效Construction Efficiency 一个月大约能施工 100，000 m2 ，About 100,000 m2 can be finished in one month. 2．低能量强夯法的加固原理Reinforcement mechanism of low energy dynamic consolidation 3．施工方案 Construction plan 1）.施工降水dewatering 场地降水采用真空强排水(well-point dewatering)，在地下水位降至地面下2.5m(underground water dewatered to 2.5m below ground surface)以下时开始进行第一遍强夯(first pass)。。 每遍强夯后进行强排水dewatering after each tamping pass 3）.低能量强夯设备 equipment for low energy DCM 履带式吊车(25t capacity track crane)，夯锤质量(tamper weight)10~12t，锤底直径(diameter of the tamper bottom)2.5m~3m 套轻型井点降水设备 light well-point dewatering equipment 4）.夯击工艺参数 tamping parameters and technique 5）.收锤参考标准 tamping-stop standard （1）夯坑周围出现明显隆起和侧向位移generate apparent heave or lateral displacement; （2）后一击夯沉量大于前一夯沉量crater caused by the latt