复杂地质条件下地铁联络通道冻结工程冻土温度场变化规律  

Temperature Field Change Law in Metro Link Passage Freezing Engineering under Complex Stratigraphical Conditions

作　　者：张潮潮 崔猛[1,2] ZHANG Chaochao;CUI Meng(School of Civil and Architectural Engineering,Nanchang Institute of Technology,330099,Nanchang,China;不详)

机构地区：[1]南昌工程学院木土与建筑工程学院,南昌330099 [2]江西省水利土木特种加固与安全监控工程研究中心,南昌330099

出　　处：《城市轨道交通研究》2023年第9期150-154,159,共6页Urban Mass Transit

基　　金：国家自然科学基金项目(52268059)。

摘　　要：目的:揭示冻土形成与发展的过程可以为复杂地质条件下的冻结法施工提供科学依据,因此需研究冻结过程中冻土温度场的变化规律。方法:以福州地铁某江底联络通道冻结工程为例,开展土体热物理参数试验及冻结温度场试验。通过试验获得土体的导热系数、比热容、冻结温度等重要热物理参数值,以及冻结温度分别为-5℃、-10℃、-15℃和-20℃时,冻土温度场的变化规律。利用ANSYS有限元计算软件开展了冻土温度场数值计算分析,获得了不同冻结时间下,冻结温度场计算分布图、沿路径A—B的温度分布情况、有效厚度范围内冻土的平均温度等计算结果,并与工程实际测量值进行了对比分析。结果及结论:冻结温度越低,土体温度的变化速率越快;当冻结温度为-5℃、-10℃、-15℃及-20℃时,距离冷源最远处的测温孔测量得到的冻结温度稳定值分别为0.75℃、-3.00℃、-4.00℃及-7.50℃,稳定温度与相应冻结温度之间的差值分别为5.75℃、7.00℃、9.00℃以及12.50℃;该冻结工程冻土交圈时间为30 d,积极冻结时间为45 d,冻土平均温度达到了-14.80℃;计算结果与实测数据基本吻合,误差在工程允许范围之内,验证了所提数值计算模型对温度场计算结果的可靠性。Objective:To reveal the formation and development process of frozen soil can provide scientific basis for freezing method construction under complex stratigraphical conditions,thus it is necessary to study the frozen soil temperature field change law of freezing process.Method:Taking a river bottom link passage freezing engineering of Fuzhou Metro as example,soil thermophysical parameter tests and freezing temperature field tests are carried out.Values of important soil thermophysical parameters including thermal conductivity,specific heat capacity,freezing temperature are obtained through the tests,as well as the change law of the frozen soil temperature field when the freezing temperature is-5℃,-10℃,-15℃and-20℃respectively.Frozen soil temperature field numerical calculation analysis is carried out by ANSYS finite element calculation software,and calculation results such as freezing temperature field calculation distribution diagram,temperature distribution along path A-B,average temperature of frozen soil in effective thickness range under different freezing time conditions are obtained and compared with engineering field-measured values for analysis.Result&Conclusion:The lower the freezing temperature,the faster the soil temperature change rate.When the freezing temperature are-5℃,-10℃,-15℃,and-20℃,the soil temperature stable values measured by the temperature measuring hole farthest from the cold source are 0.75℃,-3.00℃,-4.00℃,and-7.50℃,respectively.The difference between the stable temperature and the corresponding freezing temperature is 5.75℃,7.00℃,9.00℃,and 12.50℃,respectively.In the freezing engineering,the frozen soil closing time is 30 d,active freezing time is 45 d,frozen soil average temperature reaches-14.80℃.The calculation results generally comply with the measurement data,errors are within the engineering allowable range,thus verifying the reliability of the proposed numerical calculation model on temperature field calculation results.

关 键 词：地铁 联络通道 冻结工程 冻土温度场 

分 类 号：TU472.9[建筑科学—结构工程]