摘要
土遗址主要建筑材料为土,长期暴露在自然环境下,损坏情况普遍且严重,亟待修复。在粉土中单独及混合掺入石灰和聚丙烯纤维制备改性土试样,开展直剪、压缩、风沙侵蚀、冻融和水稳性试验,以检验聚丙烯与石灰作为粉土遗址修复材料的可行性。试验表明,单独掺入石灰或聚丙烯纤维均能提高土的抗剪强度,当掺入9%石灰或0.25%聚丙烯纤维时,改性土内摩擦角和黏聚力可高达48.9°和107.11kPa,土的压缩性也显著降低。但单独加入聚丙烯纤维反而会导致改性土的水稳性变差,这是由于土中的聚丙烯纤维增加了水的入渗通道。通过以0.25%聚丙烯纤维和9%石灰制成混掺改性土试样,其黏聚力和内摩擦角不仅比单掺改性土最高提升了66.7%和28.9%,且试样水稳定性也显著增强,抵抗风沙侵蚀和冻融的能力也有较大改善,总体性能较优。因此混合使用石灰和聚丙烯纤维能更有效地改善粉土的工程性能。
The main building material of earthen sites is soil and has been exposed to the natural environment for a long time,their damage is common and serious,and urgently needs to be restored.Especially in northwest China,there are many silty sites with poor engineering properties and difficult reinforcement.The modified soil samples were prepared by adding lime and polypropylene fibers separately and in a mixed manner in loess.Direct shear,compression,wind sand erosion,freeze-thaw,and water stability tests were conducted to verify the feasibility of using polypropylene and lime as restoration materials for silty sites.The test shows that the shear strength of the soil can be improved by adding lime or polypropylene fiber alone.When 9%lime or 0.25%polypropylene fiber is added,the internal friction angle and cohesion of the modified soil can be as high as 48.9°and 107.11kPa,and the compressibility of the soil is also significantly reduced.However,the addition of polypropylene fiber alone will lead to the deterioration of the water stability of the modified soil,which is due to the fact that the polypropylene fiber in the soil increases the infiltration channel of water.By using 0.25%polypropylene fiber and 9%lime to make mixed modified soil samples,the cohesion and internal friction angle are not only 66.7%and 28.9%higher than those of single-doped modified soil,but also the water stability of the samples is significantly enhanced.The ability to resist wind-sand erosion and freeze-thaw is also greatly improved,and the overall performance is better.Therefore,the mixed use of lime and polypropylene fiber can more effectively improve the engineering performance of silt.
作者
王贵军
刘义
孔德泉
顿帅康
悦腾达
吴小龙
宋庆祥
WANG Guijun;LIU Yi;KONG Dequan;DUN Shuaikang;YUE Tengda;WU Xiaolong;SONG Qingxiang(Shaanxi“An-Cheng”(Gansu)Construction Investment Co.,Ltd.,Lanzhou,Gansu 730070,China;Shaanxi Academy of Building Sciences Co.,Ltd.,Xi’an,Shaanxi 710082,China;School of Civil Engineering,Chang’an University,Xi’an,Shaanxi 710061,China)
出处
《施工技术（中英文）》
CAS
2024年第10期156-166,共11页
Construction Technology
基金
陕西省自然科学基金(2020JM-235,2022JM-262)。
关键词
土遗址
聚丙烯纤维
石灰
粉土
改性土
试验
earthen sites
polypropylene fiber
lime
silt
modified soil
tests
