季冻区路基水温状况监测及强度变化的研究

发布时间：2018-05-06 02:05

本文选题：季冻区 + 路基　；参考：《东北林业大学》2014年硕士论文

【摘要】：季冻区路基的病害主要是冻胀和融沉,公路路基病害大多是由路基强度的降低造成的,路基产生冻融破坏的主要因素是土体湿度的变化和随季节变化的温度,而直接的原因是经过冻融循环后路基强度的变化。因此,获取季冻区路基土温度、湿度、强度数据及其变化规律,并以此为根据对道路进行相应的处理,对于防治季冻区路基冻融破坏、提高公路的服务水平、延长道路的使用寿命具有重大意义。为了研究季冻区路基温度、湿度变化规律,自主开发了路基温度和湿度远程自动采集系统,选取两条道路三个断面布设温度湿度传感器,利用远程路基温湿度采集系统连续监测路基温度湿度变化情况,并在冻融前后用人工钻孔法采取土样,测定路基土的含水率；利用PANDA2可变能量贯入仪采集路基强度数据,并在室内进行模拟冻融循环强度试验,对PANDA2可变能量贯入仪采集的结果进行验证。结果表明：远程路基温湿度采集系统功能齐全,实现了实时连续采集路基内各个深度的温度和湿度数据,并利用无线传输技术将采集的数据及时准确地传送至用户端。路基中央分隔带处冻结深度比两侧路肩处大,与大地相比,路基冻结速度快、冻结深度深,但开始融化的时间晚,持续的融化的时间长；融化期阳面早于阴面,融化速度也大于阴面,路基填土高的冻结深度大,填土高度相同时路基宽度小的冻结深度大；在冻融循环过程中填筑材料和位置相同时路基填土高的其土体含水率小。路面积雪融化的渗透会使路基含水率增大；冻融循环前后PANDA2可变能量贯入仪现场采集的数据表明,路基强度在5月份土体融化之后下降幅度较大,在同等条件下,经过冻融循环后路基填高大的路基强度高；室内模拟试验表明,含水率、压实度、冻融循环是影响路基强度的重要因素,路基土在经过冻融循环之后,其回弹模量有变小的趋势,随着冻融循环次数的增加这种趋势越来越小。
[Abstract]:The disease of subgrade in the seasonal frozen section is mainly frost heaving and thaw settlement . Most of the subgrade diseases of the highway are caused by the decrease of the subgrade strength . The main factors of the thaw damage of the subgrade are the change of the soil moisture and the change of the subgrade strength with the season . Therefore , the temperature , humidity , intensity data and the variation law of the subgrade soil in the seasonal frozen section are obtained . Therefore , according to the corresponding treatment of the road , the subgrade soil temperature , humidity , intensity data and the variation law of the road are obtained . Therefore , it is of great significance to control the freeze - thaw damage of the subgrade in the seasonal frozen area , improve the service level of the highway and prolong the service life of the road .

In order to study the change rule of subgrade temperature and humidity in the seasonal frozen section , the remote automatic acquisition system of subgrade temperature and humidity was developed autonomously . The temperature and humidity sensors were set up in three sections of the two roads . The temperature and humidity of the subgrade were continuously monitored by the remote subgrade temperature and humidity acquisition system , and soil samples were taken by manual drilling method before and after freezing and thawing , and the water content of roadbed soil was determined ;
The results show that the remote subgrade temperature and humidity acquisition system has complete functions , realizes real - time continuous acquisition of temperature and humidity data of various depths in the subgrade , and uses the wireless transmission technology to transmit the collected data to the user terminal in a timely and accurate manner .
The thaw duration is higher than that of the pudendal surface and the melting speed is bigger than that of the pudendal surface . The frozen depth of the roadbed filling is large , and the freezing depth of the subgrade width is small when the filling height is the same ;
When the filling material and the position are the same in the freeze - thaw cycle , the soil moisture content of the subgrade is small , and the infiltration of the snow melting of the pavement can increase the water content of the subgrade ;
The data collected on the field of PANDA2 variable energy penetration instrument before and after the freeze - thaw cycle shows that the subgrade strength decreases after thawing in May , and under the same condition , the subgrade is filled with high subgrade strength after freeze - thaw cycles ;
The indoor simulation tests show that the water content , compactness and freeze - thaw cycle are the important factors affecting the subgrade strength , and the rebound modulus of the roadbed soil after the freeze - thaw cycle is smaller . As the number of freeze - thaw cycles increases , the trend is getting smaller and smaller .

【学位授予单位】：东北林业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.1

【参考文献】