公路湿陷性黄土地基处理关键技术问题研究

Study on Key Technical Problems of Highway Collapsible Loess Ground Treatments

以公路工程中湿陷性黄土地基处理常用的换填垫层法、冲击碾压法、强夯法、挤密桩法为对象,研究了这几种方法在实际工程应用中涉及到的石灰掺量、安全距离、有效处理深度、桩间距以及成桩工艺等关键技术问题。结果表明:石灰土垫层合理的掺灰量是6%~8%;强夯施工安全距离受限时开挖隔振沟宜靠近强夯点,且深度不小于2m;考虑含水率修正的强夯有效处理深度计算方法能够满足工程的需要;根据理论公式计算的挤密桩间距宜控制在2.0~2.5倍的桩径范围内,以保证其处理效果。

In highway engineering,the lime soil cushion,impact compaction,dynamic compaction and compaction pile are commonly used as treatment methods of collapsible loess ground.In this paper,the key technical problems of lime content,safeguard distance,effective treatment depth,pile spacing and pile-forming technology involved in the application of these methods in practical engineering are studied.The results show that:the reasonable lime content of lime soil cushion is 6%~8%;when the safe distance of dynamic compaction is limited,the vibration-isolating slot should be excavated close to the dynamic compaction point,and the depth should not be less than 2 m;the calculation method of effective treatment depth of dynamic compaction considering water content correction can meet the needs of engineering;the distance between compacted piles calculated by theoretical formula should be controlled in the range of 2.0-2.5 times of the pile diameter to ensure the treatment effect.