温控动三轴试验装置的研制及应用

 为研究温度对土动力特性的影响，设计了内外联合加热的温控装置，研制了温控动三轴试验系统。该系统能实现10 ℃～100 ℃范围内试样温度的精确控制，并可线性调节、分级加温。最后，以宁波饱和淤泥质软黏土为例，初步开展了不同温度下的土动力特性试验，验证了其有效性和可靠性，试验结果表明：在不同温度下，试样的滞回圈形状及发展与常规动三轴试验结果一致；随着温度的升高，软黏土的塑性累积应变、动阻尼比和动孔压减小，动弹性模量增大，且各增量值均随温度上升而减小，反映了软黏土的热硬化特征；累积塑性应变与温度归一化结果呈指数关系。

APPLICATION AND DEVELOPMENT OF A TEMPERATURE- CONTROLLED DYNAMIC TRIAXIAL TEST SYSTEM

To investigate the effect of temperature on the dynamic characteristics of soil，a temperature-controlled cyclic triaxial test system was developed by using combined heating apparatus. The system can precisely realize linear，hierarchical control of sample temperature in the range of 10～100℃. Then，the saturated silt soft clay in Ningbo area is taken for example，and a series of application tests for dynamic characteristics under different temperatures are preliminarily carried out，which validate the effectiveness and reliability of the system. Test results showed that characteristics and development of hysteretic curves under different temperature is consistent with that of general triaxial test system. With the increase of temperature，plastic cumulative strain，dynamic damping ratio and dynamic pore pressure of the soft clay decreased and inversely for dynamic elastic modulus，and the incremental values for above parameters were gradually reduced with the increasing of temperature，from which the hot hardened features is revealed. Furthermore，normalized result of cumulative plastic strain and temperature is exponential.