引江济淮工程膨胀土下伏崩解岩边坡处治试验研究  

Experimental study on treatment of disintegrating rock under expansive soil slope at Yangtze-to-Huaihe water diversion project

作　　者：李国维[1,2] 赫新荣 李铭 王志勇[4] 吴少甫 江永强 吴建涛[2] 陈伟 LI Guowei;HE Xinrong;LI Ming;WANG Zhiyong;WU Shaofu;JIANG Yongqiang;WU Jiantao;CHEN Wei(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210098,China;Highway and Railway Research Institute,Hohai University,Nanjing 210098,China;Anhui Provincial Group Limited for Yangtze-to-Huaihe Water Diversion,Hefei 230000,China;China Railway Siyuan Survey and Design Group Co.Ltd.,Wuhan 430063,China;No.2 Engineering Corporation Limited of CR20G,Beijing 100000,China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]河海大学道路与铁道工程研究所,江苏南京210098 [3]安徽省引江济淮集团有限公司,安徽合肥230000 [4]中铁第四勘察设计院集团有限公司,湖北武汉430063 [5]中铁二十局集团第二工程有限公司,北京100000

出　　处：《中南大学学报（自然科学版）》2022年第1期51-74,共24页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(42177126,41472240,51378008)。

摘　　要：为论证引江济淮工程规划的可行性,针对膨胀土和崩解岩的处治问题,采用原位试验的方法,辅助采用模型试验和室内试验方法,在工程的可行性研究阶段开展试验工程,针对膨胀土及崩解性砂软岩的防护问题开展研究。研究结果表明:江淮膨胀土层呈非连续分布,主要呈弱膨胀性、低渗透性,新生裂隙深度在6个月时可达1.2 m。膨胀土强度指标黏聚力的合理试验面积近似为表面裂隙率统计面积的合理面积与比例系数的乘积。采用PIV成像技术可建立膨胀土样本在限定风干条件下的表面面积收缩时程线,据此鉴别原状土的膨胀性。采用崩解性砂软岩改良膨胀土,可提高改良土的耐久性;当砂岩质量分数为30%时,综合改良效果最佳。循环荷载会加剧锚杆体界面的黏结蜕化;GFRP锚杆用于渠道软岩边坡加固其承载能力比钢筋锚杆的强,与胶结体的变形协调性更好,预应力衰减率更低。膨胀土下伏崩解性软岩边坡的防护方法为:水下边坡采用改性土换填与锚杆(钢筋、GFRP筋)加固,水上膨胀土边坡的改性土换填厚度采用1.0 m(弱膨胀土)、1.5 m(中膨胀土);弱膨胀土中钢筋和GFRP筋锚杆的长度不宜小于5.0 m,软岩中钢筋锚杆长度不宜小于3.5 m,GFRP筋锚杆长度不宜小于3.0 m。In order to demonstrate the feasibility of the project planning of Yangtze-to-Huai water diversion,a test project was carried out in the feasibility study stage to deal with the problems of expansive soil and disintegrating rock.A number of studies were carried out on the protection of expansive soil and disintegrating sand-soft rock,and a series of research results were obtained by using in-situ test method,assisted by model tests and indoor standard sample tests method.The results show that the expansive soil in Jianghuai is layered and discontinuous,mainly with weak expansibility and low permeability,and the depth of new cracks can reach 1.2 m in 6 months.The reasonable test area of the strength index cohesion of expansive soil is approximately the product of the reasonable area of the statistical area of surface crack rate and the proportion coefficient.PIV imaging technology can be used to establish the time history of surface area shrinkage of expansive soil samples under limited air-drying conditions,so as to identify the expansibility of undisturbed soil.The improvement of expansive soil by disintegrating sand-soft rock can improve the durability of improved soil.The comprehensive improvement effect is the best when the mass fraction of sandstone is 30%.Cyclic loading will aggravate the bond degradation of the bolt interface.When GFRP bolt is used to reinforce the soft rock slope of the channel,its bearing capacity is better than that of steel bolt,the deformation coordination with the cement is better,and the prestress attenuation rate is lower.The protection method of the disintegrating soft rock slope under the expansive soil is as follows:the underwater slope is replaced with modified soil and reinforced with bolts(steel and GFRP bolt),and the modified soil replacement thickness of expansive soil slope above water is 1.0 m(weak expansive soil)and 1.5 m(medium expansive soil).The length of the steel and GFRP bolt in weak expansive soil should not be less than 5.0 m.The length of the steel bolt in soft

关 键 词：引江济淮 膨胀土 崩解性砂软岩 防护措施 

分 类 号：TU43[建筑科学—岩土工程]