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胡    璇

（ 陕西铁路工程职业技术学院 ，陕西 渭南 714000)

摘   要： 城市地下工程施工中，富水基坑边坡粉细砂地层稳定性较差，易出现涌水、涌砂等地质灾害。为研究富水基坑边坡粉细砂地层加固防渗技术，室内利用聚氨酯( PU) 和粉煤灰材料制备了新型 PU/粉煤灰注浆材料，并对新型注浆材料注浆加固的粉细砂结石体展开了力学试验和细观特征观察。试验结果表明：( 1) 养护龄期越长，结石体的抗压强度则越大。当粉煤灰掺量为 10%、养护龄期为12 h 时，结石体的抗压强度最大，达 到 6. 89 MPa; (2) 浸水后注浆结石体的抗压强度明显变低，试件的抗压强度与浸水时间之间成负指数关系。当浸水时间为 9 d 时，粉煤灰掺量为 10%的注浆结石体抗压强度最大，此时其抗压强度为 3. 55 MPa; ( 3) 含水率越高，则注浆结石体的内部结构越松散； 而当水解时间达到9 d 后，注浆结石体内部产生了大量的裂隙，结石体内部结构破坏严重，因此结石体的力学性质变差。

关键词： 基坑工程； 富水； 粉细砂地层； 注浆加固； 力学试验； 细观特征

中图分类号： TU45      

文献标志码： A      

文章编号： 1005-8249 (2023) 03-0013-05

DOI : 10. 19860/j.cnki.issn1005-8249.2023.03.013

HU Xuan

( Shaanxi Railway Institute , Weinan 714000 , China)

Abstract: In the construction of urban underground engineering, the stability of silty fine sand stratum on the slope of water rich foundation pit is poor, and geological disasters such as water gushing and sand gushing are easy to occur. In order to study the anti-seepage technology of silty fine sand stratum of water rich foundation pit slope, a new PU/ fly ash grouting material was prepared by using polyurethane (PU) and fly ash materials indoors, and the mechanical tests and meso characteristics of the silty fine sand stone body reinforced by the new grouting material were carried out. The results show that: (1) the longer the curing age, the stronger the bearing capacity of the stone body. When the content of fly ash is 10% with the curing age at 12 h, the compression strength of the stone body reaches the maximum, reaching 6.89 MPa; (2) The compression strength of the grouted stone becomes lower obviously after immersion, and there is a negative exponential relationship between the compression strength and immersion time. When the soaking time is 9 d, the bearing capacity of grouting stone body with 10% fly ash is the best, and its compression strength is 3.55 MPa; (3) the higher the water content is, the looser the internal structure of the grouting stone body is; When the hydrolysis time reaches 9D, a large number of cracks are produced in the interior of the grouting stone, and the internal structure of the stone is seriously damaged, so the mechanical properties of the stone become worse.

Keywords :  foundation  pit  engineering;  rich  water;  silty  fine  sand  stratum;  grouting  reinforcement;  mechanical  test;

mesoscopic features

∗基金项目： 陕西铁路工程职业技术学院科研项目 ，富水基坑边坡粉细砂地层注浆防渗加固技术研究  ( KY2022-47) 

作者简介： 胡璇  (1993—) , 女，硕士。主要研究方向：隧道与边坡。

收稿日期： 2022-06-10