活性氧化镁碳化搅拌桩模型试验研究

发布时间：2018-03-13 15:25

本文选题：活性氧化镁　切入点：碳化　出处：《岩土工程学报》2017年S2期 　论文类型：期刊论文

【摘要】：软弱土须经适当的人工处理才能满足建筑和基础设施的承载需要,而MgO碳化搅拌桩法是一种创新型的地基处理技术,即将CO_2气体通到拌有活性MgO的搅拌桩体中,通过一系列物理化学反应,形成稳定性好、承载力高的复合地基。基于此,采用人工挖孔制桩法,开展了不同初始含水率和不同CO_2通气压力下室内搅拌桩模型试验,碳化过程中进行桩体温度监测,碳化后对桩体进行无侧限抗压强度和含水率测试。结果表明:搅拌桩温度在不足2h碳化时间可达到最高,且峰值温度在初始含水率为20%时最高、在15%时次之、在30%时最低;峰值温度随CO_2通气压力增加而增加。碳化搅拌桩强度随初始含水率增加而减小,随CO_2通气压力增加而增加,且强度随含水率呈指数形式递减。碳化搅拌桩模型试验将为MgO碳化技术在软土地基加固工程中的应用提供理论指导。
[Abstract]:Soft soil must be treated manually to meet the bearing capacity needs of buildings and infrastructure, and MgO carbonized mixing pile is an innovative foundation treatment technology, that is, CO_2 gas flows into the mixing pile body with active MgO. Through a series of physical and chemical reactions, the composite foundation with good stability and high bearing capacity was formed. Based on this, the indoor mixing pile model test under different initial moisture content and different CO_2 ventilation pressure was carried out by means of manual digging pile making method. During carbonation, the pile temperature is monitored, and the unconfined compressive strength and moisture content of the pile are tested after carbonization. The results show that the mixing pile temperature can reach the highest in less than 2 h carbonization time, and the peak temperature is the highest when the initial moisture content is 20. The peak temperature increased with the increase of CO_2 pressure. The strength of carbonized mixing pile decreased with the increase of initial moisture content, and increased with the increase of CO_2 pressure. And the strength decreases exponentially with moisture content. The model test of carbonized mixing pile will provide theoretical guidance for the application of MgO carbonization technology in soft soil foundation strengthening engineering.
【作者单位】：东南大学岩土工程研究所;江苏省城市地下工程与环境安全重点实验室;
【基金】：国家自然科学基金项目(51279032,41330641,41372308) 国家重点研发课题(2016YFC0800201)
【分类号】：TU473.1

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