Experiment and Analysis on Rheology Dynamic Characteristics of Soft Soil

2013 ◽  
Vol 275-277 ◽  
pp. 299-303
Author(s):  
Hua Hu ◽  
Xiao Xu Zheng

The rheologic action of the soft soil could be accelerated by earthquake the dynamic loading, which induces more geotechnical engineering accidents and geologic disasters. The samples of marine deposit soft soil are collected in xiamen, and the rheologic rate, rheologic acceleration and rheologic strain under the dynamic loading of sinusoidal variation are tested and analyzed by using dynamic-triaxial device, and the influences of dynamic loading frequency and breadth to dynamic characteristics of soft soil are contrasted and analyzed. The research results have important academic signification for us to search rheologic dynamic characteristic of soft soil under dynamic loading.

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Jie Yin ◽  
Yong Tang ◽  
Yong-hong Miao ◽  
Ruo-yu Sheng

This paper presents an experimental investigation on the dynamic characteristics of soft soils that are treated by vibration-drainage method (VDM). The representative dynamic axial strain at a given number of cycles was obtained. The VDM-treated soft soil exhibited different dynamic deformation characteristics that are not only affected by the cyclic frequency but also influenced by the vibration frequency during the treatment process. Soil specimens at different cyclic frequencies show a similar variation trend that the axial strain systematically grows with increasing number of cycles. The rate of axial strain for all specimens systematically linearly decreases with the increase of number of cycles in the log-log scale. Results showed that both axial strain and strain rate exhibit relatively lower values at a given number of cycles under the condition that the applied cyclic frequency is equal to vibration frequency. It is expected that the soil structure will be more stable if the applied cyclic frequency is close to the vibration frequency that is applied on VDM-treated soil. Therefore, the vibration frequency close to the possible dynamic loading frequency is recommended in the process of soft soil improvement via VDM in the related engineering applications.


2013 ◽  
Vol 838-841 ◽  
pp. 737-740
Author(s):  
Hua Hu

The practical investigating and theoretic analysis Indicates that the rheologic action of the soft rock-soil could be accelerated by the dynamic loading, which induces more geotechnical engineering accidents and geologic disasters. The samples of marine deposit soft soil are collected in xiamen, and the dynamic stress-strain, the rheologic strain-time etc rheologic characteristics curves under the different breadth of dynamic loading of sinusoidal variation are tested using dynamic-triaxial device. The rheologic characteristics, rheologic rate and rheologic acceleration varietal process of four different breadths are analyzed. The research results indicate that all the samples are the same varietal process from decelerate rheology, relatively stable rheology to accelerate rheology stage. The dynamic strain slow growth and the rheologic process is relatively stable when the breadth of dynamic loading is low stress ranges of 10~20kPa.When the breadth of dynamic loading exceed 40kPa, the dynamic strain rapid growth and the rheologic is accelerate process till the samples destroy. The research results have academic and actual signification for us to open out the dynamic rheologic mechanics characteristic, explore the accelerating rheologic laws and the rheologic destabilizing dynamic condition of soft rock-soil under dynamic loading.


2013 ◽  
Vol 859 ◽  
pp. 222-227
Author(s):  
Hong Jun Liu ◽  
Jin Hua Tan ◽  
Xue Wen Su ◽  
Hao Wu

Two typical monitoring sections are selected for obtaining the change law of the surface subsidence and the settlement after construction of soft soil foundations, and determining the reasonable unloading time. The research results show that the surface settlement rate is large during the filling stage, the rate decreases after the loading and gradually stabilized. The embankment midline settlement is larger than the settlement of the road shoulder which is concluded from the fact that the subsidence of the middle settlement plate is larger than those of the left and right plate. The surface subsidence rate is less than 5mm per month during the two month before unloading according to the data in the tables. The settlement after construction presumed from the middle plate is more significantly larger than that of left and right sides, hence, as the unloading basis of preloading drainage method in soft soil foundation treatment the settlement after construction which is calculated from the midline monitoring data of the road is appropriate. After 6 months the calculated post-construction settlements of the two sections are in the scope of the design requirement since they decrease with preloading time. The reliable basis is provided for the future design and construction of soft foundation in this area through the research results.


2013 ◽  
Vol 341-342 ◽  
pp. 391-394 ◽  
Author(s):  
Li Qing Sun ◽  
Zhong Xxing Li ◽  
Xu Feng Shen ◽  
Jia Yi Zhu

In order to improve dynamic characteristics of air spring with auxiliary chamber, finite element model of air spring R1A390-295 with auxiliary chamber connected with pipe is established,and through analysis to the dynamic characteristics of the model, influence discipline of sitffness characteristics to air spring with different pipe, different auxiliary chamber or different initial pressure are analysed under different excitation. The result show that:minor dynamic sitffness is obtained by using larger pipe or under lower excitation frequency,and as volume of auxiliary chamber increases, the spring dynamic sitffness will decrease accordingly and its amplitude tends to gentle,and influence for decreasing the spring dynamic sitffness is not obvious by continuing to increase the auxiliary chamber volume; the spring dynamic sitffness will increases as initial pressure increases. The validity of Finite element model is verified through dynamic characteristic test .


2013 ◽  
Vol 433-435 ◽  
pp. 59-62
Author(s):  
Jiang Yong

The SGA170 mine truck was used as research object, the full hydraulic steering system and it's dynamic characteristics was simulated by the AMESim, the characteristics and simulation curve of the steering system and the steering mechanical under various conditions was obtained, which provided theoretical reference and technical support to the design and analysis of full hydraulic steering system of the heavy-duty mine truck, and has important value in the engineering.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1423-1426
Author(s):  
Dong Li ◽  
Xiao Yan Wang ◽  
Xiao Fei Lv ◽  
Xiao Ling Chen

In East China Sea, especially in Zhejiang and Fujian Provinces, classic marine deposit soft soil with characteristics of high compressibility, high sensitivity and low strength is widely distributed. Seismic subsidence occurs under earthquake causing substantial losses. Though a number of effective studies are carried out on the causes, mechanisms and methods on seismic subsidence, there are more other aspects to be studied due to marine soil’s complexity. In this paper, the classic marine soft soil in southern sea area of Taizhou Bay is studied on its seismic parameter based on the tri-axial seismic experiment. The seismic parameters and residual strain formula are obtained, and compared with normal continental deposit soft soil.


2012 ◽  
Vol 6 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Haruhisa Sakamoto ◽  
◽  
Taiga Matsuda ◽  
Shinji Shimizu ◽  

In this study, dynamic characteristics are determined based on the impulse response method, the correction of discretization errors and the identification of equivalent physical parameters, as found in the vibration model having one degree of freedom. In the experiments, the test tool is cylindrical bar shaped and made from solid tungsten carbide, and four toolholders with chucking mechanisms, including the shrinkfit type, collet type, hydraulic type, and press-fit type, are used. Since it had been previously confirmed that one of the tool preparation jigs had dynamic characteristics similar to those of an actual machine tool’s spindle, the dynamic characteristics of the jig could be measured the way the spindle system is measured in this study. From the experimental examinations, the following were clarified. (1) Chucking of the tooling system enhances the first mode vibration of the spindle system markedly. (2) The type of tool chuck used changes the dynamic characteristics of the spindle system. The trend in the dynamic stiffness corresponds well with that in the equivalent damping coefficient but is opposite to that in the equivalent stiffness. (3) The magnitude order of the dynamic characteristic parameters of the spindle system corresponds well with the inherent values of the dynamic characteristic parameters of the toolholders themselves; that is, the inherent dynamic characteristics of the tooling system can be used as the criteria to estimate the effect on the dynamic characteristics of the spindle system.


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