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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。
The soft soil should be properly man-made to meet the bearing needs of the construction and infrastructure. The MgO carbonation mixing piles method is an innovative foundation treatment technology, that is, the CO 2 gas is passed into the mixing piles with active MgO through A series of physical and chemical reactions, the formation of good stability, high bearing capacity of the composite foundation. Based on this, the method of manual digging hole piles was adopted to test the model of indoor mixing piles under different initial moisture content and different CO_2 ventilation pressures. During the carbonization process, the temperature of piles was monitored. After carbonation, the unconfined compressive strength And moisture content test. The results show that the temperature of the mixing pile reaches the highest carbonization time in less than 2h, and the peak temperature is the highest when the initial water content is 20%, followed by 15% and the lowest at 30%. The peak temperature increases with the increase of CO_2 ventilation pressure . The strength of carbonized mixing piles decreases with the increase of initial moisture content and increases with the increase of CO_2 ventilation pressure, and the intensity decreases exponentially with the moisture content. Carbonation mixing pile model test will provide theoretical guidance for the application of MgO carbonization technology in the soft soil foundation reinforcement engineering.