风积沙改良土路堤温度变形规律现场试验研究  

Field experimental study on temperature deformation law of improved aeolian sand embankment

作　　者：陈祥[1] 祁小博[2] 许兆义[1] CHEN Xiang;QI Xiaobo;XU Zhaoyi(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;China Institute of Geo-enviroment Monitoring,Beijing 100083,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]中国地质环境监测院,北京100083

出　　处：《铁道科学与工程学报》2023年第5期1917-1928,共12页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(41772330)。

摘　　要：新建通辽至新民北客专TLSG-3标路基工程以水泥改良风积沙作为填料,在路堤填筑过程中,路堤表层出现大量横向裂缝。为探究裂缝发生的机理并提出处置措施,在现场填筑一段试验路堤,该试验路堤总长150 m,分为5个路段,采用不同水泥、黏土掺量的风积沙改良土作为填料。通过现场试验与湿度、温度、应变监测,分析气温影响作用下不同配比风积沙改良土路堤的湿度、温度和应变变化规律。风积沙改良土路堤土体含水量总体上随着气温降低而减小,随后又随气温升高而增大,但变化幅度均不大。路堤表层土体温度受气温变化影响明显,总体上随气温变化而变化,但是具有明显的滞后性,路堤深部土体温度受气温影响相对较小。段路堤土体应变主要受土体温度变化控制,路堤表层土体应变变化较大,随土体温度下降先发生压缩变形,随后随土体温度升高,压缩变形逐渐减少,进而转为拉伸变形,路堤深部土体应变变化不大,因此路堤表层土体因温度降低发生的冷缩变形是实际工程施工时路堤浅层裂缝的主要原因;5个试验路段中,以掺5%水泥+5%黏土的改良风积沙为填料的路堤应变变化幅度最小,因此,从控制路堤土体变形的角度来看,掺5%水泥+5%黏土的改良风积沙配比要优于其他配比。The aeolian sand improved with cement was used as filler in the subgrade works of TLSG-3 bid section of passenger dedicated line from Tongliao to Xinmin north.In the process of embankment filling,a large number of transverse cracks appeared in the superficial layer of the embankment.In order to explore the mechanism of cracks and put forward treatment measures,a section of test embankment with a total length of 150 m was built on site.The embankment tests were divided into five sections,and the improved aeolian sand with different cement and clay content was used as the filler.The variation law of humidity,temperature and strain of improved aeolian sand embankment with different mixture ratio was analyzed under the influence of temperature.The soil moisture content of improved aeolian sand embankment generally decreases with the decrease of temperature,and then increases with the increase of temperature,but the change range is small.The temperature of the surface soil of the embankment is obviously affected by the temperature change,which generally changes with the temperature change,but it has obvious hysteresis.The temperature of the deep soil of the embankment is relatively less affected by the temperature.The strain of embankment soil in this section is mainly controlled by the change of soil temperature.The strain of embankment surface soil changes greatly.With the decrease of soil temperature,compression deformation first occurs,and then with the increase of soil temperature,compression deformation gradually decreases,and then turns to tensile deformation.The strain of the deep soil of the embankment changes little,so the cold shrinkage deformation of the surface soil of the embankment due to the decrease of temperature is the main reason for the shallow cracks of the embankment in the actual engineering construction.Among the five test sections,the embankment strain change range with the improved aeolian sand mixed with 5%cement and 5%clay as the filler is the smallest.Therefore,from the perspective of con

关 键 词：风积沙 改良土 高寒地区 温度 应变 

分 类 号：TU441[建筑科学—岩土工程]