摘要
人工冻结地层(砂层)中,地下水流速对冻结温度场分布规律的影响非常大,为此,自行研制了一套监测地下水不同流速对冻结温度场影响的试验装置系统,该系统由地下水渗流系统、冻结系统和温度监测系统三大子系统组成。单管冻结的试验结果表明:在地下水(流速为5 m/d)作用下,上游距离冻结中心越近位置,温度梯度越大,下游的温度梯度较平缓;与冻结中心等距位置,下游的温度明显低于上游,表明上游的冷量被水带到下游。冻结15 d时,无流速情况下,冻结发展速度较快,形成一个半径约580 mm的冻结圆柱,而5 m/d的流速时,冻结发展速度较慢,并且下游的冻结发展速度比上游的快,与无流速时相比,上游形成的冻结厚度减少了22.4%,下游减少了5.2%。三管冻结的试验结果表明:当流速由5 m/d增大10 m/d时,冻结15 d时,冻结区域的面积仅减少了7.1%,由此可见,冻结管的"群管效应"可以有效减小水流对冻结区域的不利影响,可为大流速的地下水作用下的冻结管布置方案的优化设计提供参考。
In artificial freezing layers(sand layers),the groundwater had great influence on the distribution of freezing temperature field,to this end,a test system was developed to monitor the effect of water at different flow rates on the freezing temperature field.The system was composed of three subsystems,i.e.the underground water seepage system,the freezing system and the temperature monitoring system.The experimental results of a single tube show that the temperature gradient at the upstream of the flow increases as the distance to the freezing center decreases,while the downstream temperature gradient is small under the influence of groundwater(velocity of 5 m/d).The downstream temperature is significantly lower than the upstream temperature at the same distance from the freezing center,which indicates that the upstream cooling water is taken down to the downstream.When the freezing time reaches 15 days,the freezing develops fast and forms a frozen column with a radius of about 580 mm for the groundwater without flow rate,while the frozen area develops slowly for the groundwater at the flow rate of 5m/d,the frozen area at the downstream develops faster than that at the upstream,the freezing thickness at the upstream is reduced by 22.4%,and the freezing thickness in the downstream is reduced by 5.2%.The results of the three-tube freezing test show that the frozen area decreased by only 7.1%when the flow rate increases from 5 m/d to 10 m/d and the freezing time reaches 15 days,which indicates that the“Group tube effect”can effectively reduce the impact of water flow on the frozen area.The analysis results would provide a reference for the optimal design of freezing pipe layout scheme under groundwater of a large flow rate.
作者
荣传新
张翔
程桦
王彬
林键
RONG Chuan-xin;ZHANG Xiang;CHENG Hua;WANG Bin;LIN Jian(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan 232001,China)
出处
《广西大学学报（自然科学版）》
CAS
北大核心
2018年第2期656-664,共9页
Journal of Guangxi University（Natural Science Edition）
基金
国家自然科学基金资助项目(51374010
51474004)
高校学科(专业)拔尖人才学术资助重点项目(gxbj ZD2016045)
关键词
人工冻结
地下水流速
冻结温度场
模型试验装置
artificial freezing alluvium
groundwater flow rate
freeze temperature field
model test device
作者简介
通讯作者:荣传新(1968-),男,安徽六安人,安徽理工大学教授,博士生导师;E-mail:chxrong@aust.edu.cn。
