摘要：A new multi-functional bridge seismic isolation bearing(MFBSIB) is designed and its mechanical model is developed in this *** an upper sliding device and a lower energy dispassion isolation device effectively,the new MFBSIB can adjust the deformation caused by temperature,vehicle breaks,and concrete creep,etc.,in addition to dissipating *** switch of 'slide-isolation' is achieved and the efficiency of both upper and lower parts is validated through experiment with a *** shear performance curve established in this paper is verified to be efficient in describing the mechanical characteristics of the bearing through *** is proved through both numerical calculation and experimental analysis that the new MFBSIB is endowed with enough vertical rigidity,good energy dissipation ability,stable overall performance,and good realization in expected *** performance is slightly influenced by shear stress,while affected by vertical pressure,loading frequency,slide limit,etc.,*** results could provide reference for study and application of the new MFBSIB.

摘要：In order to check the validity of the mathematical model for analyzing the flow field in the air-agitated seed precipitation tank,a scaled down experimental apparatus was designed and the colored tracer and KCl tracer were added in the apparatus to follow the real flow *** tracers were considered in the mathematical model and the algorithm of tracers was *** comparison of the results between the experiment and numerical calculation shows that the time of the tracer flows out of stirring tube are 40 s in the experiment and 42 s in numerical calculated *** transient diffusion process and the solution residence time of the numerical calculation are in good agreement with the experimental results,which indicates that the mathematical model is reliable and can be used to predict the flow field of the air-agitated seed precipitation tank.

摘要：The immersed tube tunnel section of the Shenzhen-Zhongshan Link exhibits complex geological conditions and high back sludge strength. The tunnel cushion adopts the gravel and flaky stone combined cushion. The major influencing factors of the mechanical deformation characteristics of the gravel and flaky stone composite cushion are studied through a physical model experiment. The following results are reported.(1) The load–settlement curves of the flaky stone cushion become more compact with a dense increment under the design load. These curves can be regarded as nonlinear mechanical characteristics. The load–settlement curves of the gravel cushion and the gravel and flaky stone composite cushion exhibit the characteristics of a two-stage linear change.(2) The flatness of the top of flaky stone cushion considerably affects settlement and secant modulus. The flatness of the top of flaky stone should be ensured during construction.(3) Gradation and thickness exert no evident effect on the compressibility of a cushion. The preloading pressure caused by the construction height difference of the cushion materials plays an important role in improving the initial stiffness of a cushion and reducing initial settlement and overall settlement.(4) This study investigates the preloading under 30 kPa of the 0.7-m flaky stone and 1.0-m gravel combination cushion. It recommends the following secant modulus values: 48.89 MPa for the section of 0–30 kPa and 10.47 MPa for the section of 30–110 kPa.