全自动重锤夯实机条件下DDC工法的效应特性

Effect characteristics of DDC method under full-automatic heavy hammer compactor

DDC地基处理技术作为一种传统的松软地基土处理方法,通过采用改进的夯扩自动化施工新设备和技术,解决了自身操作的问题,且扩大了夯扩直径,加大了夯实深度等。结合西北黄土地区某电厂现场施工原位测试过程和ABAQUS有限元软件,对全自动重锤新设备夯扩条件下DDC复合地基进行了相关研究。结果表明:1)设计桩位成孔为400 mm时,全自动重锤夯扩后孔位直径可达600～800 mm; 2)采用新设备进行地基夯扩处理时,存在一个最适宜夯扩次数,本文即为4次; 3)其土体夯扩加固区在水平方向范围可达5倍夯锤直径。可得结论:在全自动重锤夯实设备及技术条件下,夯扩处理后的土体成桩直径及土体处理深度均满足设计要求。

The DDC method is a traditional way of foundation treatment for the soft foundation soil. By using the improved new technology and equipment of ramming and expanding automation, some self-operation problems are solved, the ramming diameter and compacting depth are increased and so on. Based on the field test of a power plant in the northwest loess area and the ABAQUS software, the related researches of DDC composite foundation under the new technology conditions are conducted, and the results show as follows ： 1 ） When the designed diameter of the pile hole is 400 mm, and it can reach 600 - 800 mm after ramming; 2） There exists a most suitable ram number of times when ramming the foundation using new equipment, which is 4 times; 3 ） The reinforcement area can reach 5 times of the ramming diameter in the horizontal direction. The following can be concluded ： under the conditions of full automatic hammer ramming equipment and technique, the soil mass pile diameter and the soil mass treatment depth all meet the design requirements.