基于强度试验的水泥土搅拌桩施工综合参数研究

Study on Construction Technology Coordination Parameters of Cement Soil Mixed Piles Based on Strength Tests

水泥土搅拌桩因其施工方便、环境污染小、布置灵活、经济等优点,而被广泛应用于水利工程、市政道路工程和城市基建基础工程等工程.以佛山新城CBD特大型基坑支护结构为背景,从水泥与土的微观作用机理出发,分析了影响水泥土工程特性的几种主要因素,包括水泥掺量、含水量、水泥龄期及土性等,并以似水泥掺量、综合含水率和水泥龄期为控制变量对水泥土进行室内无侧限抗压强度试验,获得其强度变化规律.试验结果表明,水泥土无侧限抗压强度随着水泥掺量和龄期的增加而提高,随着综合含水率的增加而降低.最后根据合理可行的施工工艺参数,包括水泥土现场配合比、搅拌轴转速、搅拌提升下沉速度、复搅遍数等,推导出水泥土搅拌法施工综合协调参数公式.

Cement soil mixed piles are widely used in irrigation works,municipal road projects and urban infrastructure projects due to its advantages of convenience to construction,little pollution to environment,flexible arrangement and economic efficiency.This paper takes the extra large foundation pit support of Foshan new town CBD as the background and analyses the factors affecting the engineering characteristics of cement soil based on themicroscopic action mechanism between cement and soil,which include cement content,water content,age of cement and properties of soil.And strength distributing rule of cement soil is obtained through indoor unconfined compressive strength tests,where the control variables are cement content,comprehensive water content and age of cement.The test results show that the unconfined compressive strength of cement soil increases with the increase of cement content and age,and decreases with the increase of comprehensive water content.Finally,this paper deduces the comprehensive coordination parameter formula for the construction of cement soil mixed method according to the reasonable construction technology parameters,including field mix proportion of cement soil,rotating speed of stirring shaft,lifting and sinking speed of stirring shaft and times of duplicate stir.