黑棉土路基处治设计  

Design for Treatment of Subgrade on Black Cotton Soil(BCS)

作　　者：王晓帆 王跃[2] 张艳红[3,4] 

机构地区：[1]中交一公局公路勘察设计院有限公司,北京市100024 [2]中交第一公路勘察设计研究院有限公司,西安市710075 [3]长安大学特殊地区公路工程教育部重点实验室,西安市710064 [4]中国公路工程咨询集团有限公司,北京市100097

出　　处：《公路》2012年第9期46-53,共8页Highway

摘　　要：黑棉土是埃塞俄比亚当地特有的一种膨胀土。以埃塞俄比亚某高速公路为依托,介绍黑棉土路段的路基处治设计。结合当地既有的工程实例,以及某高速路已经完工和正在修建的路段,对黑棉土的膨胀特性、黑棉土路段路基病害和成因进行分析。结果表明:黑棉土的主要破坏模式为干湿循环造成黑棉土胀缩效应;黑棉土治理应遵循"防排结合、多方类比、谨慎换填、及时取样"的原则;对尚未施工的黑棉土路段低填路基处治设计,应从施工准备、施工过程与施工后的防水设计、地表水与地下水排水设计、填料设计以及边坡设计(封闭坡面、放缓坡率)等方面入手加以优化;建议在线形设计时对黑棉土路段排水预留条件;从设计到施工,黑棉土路段路基应始终贯彻"保水、防渗"原则。The treatment of Black Cotton Soil is pia, where the Black Cotton Soil widely distributed. the main concern in the construction activity in Ethio- The paper will discuss the treatment measurements of Black Cotton Soil depending on the experience of an expressway under construction in this country. Analy- sis will be made on the expansive characters of Black Cotton Soil and why the subgrade with a relatively low fill height on the Black Cotton Soil cracked. It is found that the subgrade on the BCS soil cracked be- cause of the expansive and shrinkage activity under the influence of water; the treatment measurements shall be as per the principals as the following., carrying out the drainage design carefully and comparing the current project with similar roadway, taking samples for tests and replace the BCS with suitable material at a reasonable depth. As for the uncompleted stretches of subgrade with low filling and cutting height, it is suggested preparations made from the beginning of construction to the post-construction stage, including drainage design, dealing with the surface and underground water, replacing with suitable material at rea- sonable depth, slope optimization and so on. It is strongly recommended that the drainage for the BCS soil shall be taken into account when confirming the alignment. In a word, all the design and construction ac- tivity for the subgrade on BCS shall stick to the idea keeping the water in the BCS and preventing the water from outside.

关 键 词：黑棉土 膨胀特性 路基开裂 红土砾料 山皮土 填料设计 隔 排水设计 

分 类 号：U416.1[交通运输工程—道路与铁道工程]