Dynamic properties of some cohesive soils of Ontario

1981 ◽  
Vol 18 (3) ◽  
pp. 371-389 ◽  
Author(s):  
T. C. Kim ◽  
M. Novak

The dynamic behaviour of some cohesive soils of southwestern Ontario is experimentally investigated using a resonant column apparatus. Attention is concentrated particularly on the dynamic shear modulus, Young's modulus, and damping ratio. The variation of these characteristics with void ratio, confining pressure, strain, and stress history is studied. Data are presented that can be utilized in the design of foundations and structures exposed to dynamic loads.

2020 ◽  
Vol 12 (4) ◽  
pp. 1616 ◽  
Author(s):  
Xianwen Huang ◽  
Aizhao Zhou ◽  
Wei Wang ◽  
Pengming Jiang

In order to support the dynamic design of subgrade filling engineering, an experiment on the dynamic shear modulus (G) and damping ratio (D) of clay–gravel mixtures (CGMs) was carried out. Forty-two groups of resonant column tests were conducted to explore the effects of gravel content (0%, 10%, 20%, 30%, 40%, 50%, and 60%, which was the mass ratio of gravel to clay), gravel shape (round and angular gravels), and confining pressure (100, 200, and 300 kPa) on the dynamic shear modulus, and damping ratio of CGMs under the same compacting power. The test results showed that, with the increase of gravel content, the maximum dynamic shear modulus of CGMs increases, the referent shear strain increases linearly, and the minimum and maximum damping ratios decrease gradually. In CGMs with round gravels, the maximum dynamic shear modulus and the maximum damping ratio are greater, and the referent shear strain and the minimum damping ratio are smaller, compared to those with angular gravels. With the increase of confining pressure, the maximum dynamic shear modulus and the referent shear strain increase nonlinearly, while the minimum and maximum damping ratios decrease nonlinearly. The predicting equation for the dynamic shear modulus and the damping ratio of CGMs when considering confining pressure, gravel content, and shape was established. The results of this research may put forward a solid foundation for engineering design considering low-strain-level mechanical performance.


2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Gyeong-o Kang ◽  
Woong Choi ◽  
Changho Lee

This paper aims to propose predictive equations for the small-strain shear modulus (Gmax) and small-strain damping ratio (Dmin) of a granulated mixture with plastic and nonplastic materials to reduce the dynamic energy of the ground. Polyurethane bead (PB) and glass bead (GB) were used as the plastic and nonplastic materials, respectively. 180 resonant-column tests were conducted with various conditions affecting the dynamic properties, such as nonplastic particle content (PC), void ratio (e), particle-size ratio (sr), and mean effective confining pressure (σm′). The results showed that Gmax and Dmin, respectively, increased and decreased as e decreased with increasing σm′ of material mixtures. In addition, Gmax decreased with an increase in PC, whereas Dmin increased. It was also found that sr of materials affected the changes in Gmax and Dmin. With an increase in sr, Gmax increased while Dmin decreased because small particles do not hinder the behavior of large particles as the size of larger particles increases. Finally, based on the results, new equations for estimating Gmax and Dmin of a granulated mixture with PB and GB were proposed as functions of PC, e, median grain size (D50), and σm′.


2011 ◽  
Vol 105-107 ◽  
pp. 1426-1432 ◽  
Author(s):  
De Gao Zou ◽  
Tao Gong ◽  
Jing Mao Liu ◽  
Xian Jing Kong

Two of the most important parameters in dynamic analysis involving soils are the dynamic shear modulus and the damping ratio. In this study, a series of tests were performed on gravels. For comparison, some other tests carried out by other researchers were also collected. The test results show that normalized shear modulus and damping ratio vary with the shear strain amplitude, (1) normalized shear modulus decreases with the increase of dynamic shear strain amplitude, and as the confining pressure increases, the test data points move from the low end toward the high end; (2) damping ratio increases with the increase of shear strain amplitude, damping ratio is dependent on confining pressure where an increase in confining pressure decreased damping ratio. According to the test results, a reference formula is proposed to evaluate the maximum dynamic shear modulus, the best-fit curve and standard deviation bounds for the range of data points are also proposed.


2011 ◽  
Vol 374-377 ◽  
pp. 1391-1395
Author(s):  
Xue Song Lu ◽  
Wei Xiang

Based on the red clay of Wuhan reinforced by Ionic Soil Stabilizer, the red clay soil is treated by different matches of ISS at first, then is tested in the Atterberg limits test and dynamic triaxia test. The results show that the plastic index decreases, and the red clay were greatly improved under the dynamic condition, the maximum dynamic shear modulus ratio acquired an incensement of 27.72% on average after mixing the ISS into the red clay. In addition, It was concluded that the confining pressure influenced the dynamic shear modulus and damping ratio to a certain extent. Given the same strain conditions, with the incensement of confining pressure increases, the dynamic shear modulus increased and the damping ratio decreased. Moreover, when plotting the dynamic shear modulus versus the dynamic shear strain, the similar curve can be formed for both the natural soil and the modified one, the dynamic shear modulus monotonously decreased with the incensement of the dynamic shear strain. However, the value of dynamic shear modulus differed in the same shear strain between the natural soil and the soil modified by ISS.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Kaisheng Chen ◽  
Qinqin Wang ◽  
Dipu Luo ◽  
Bo Zhou ◽  
Kun Zhang

Rubber powder formed from discarded tire rubber is mixed with red clay to form a rubber-red clay mixture. The dynamic triaxial test was carried out on the mixtures under different conditions. The effects of rubber content, rubber particle size, moisture content of mixed soil, compactness, confining pressure, and vibration frequency on shear strain relation, dynamic shear modulus, and damping ratio of the mixture were investigated. The results show that under the same dynamic strain, the dynamic shear stress-strain curve of rubber mixed soil decreases with the increase in rubber particle content and moisture content and decrease in rubber particle size. On the other hand, it increases with the increase in compactness, confining pressure, and vibration frequency, and as the dynamic strain increases, the τd-γd curve becomes more nonlinear. In addition, with the increase in the rubber particle content, the dynamic shear modulus decreased while the damping ratio increased. When the content was 2%, the change was fastest. After continued addition, it gradually became stable, and when the decrease in rubber particle size also shows the same pattern, 2.00 mm rubber-red clay mixture shows better structure. The water content has great influence on dynamic shear modulus and damping ratio of rubber-red clay mixtures. With the increase in compactness, confining pressure, and vibration frequency, the interaction between mixed soil particles was enhanced, the dynamic shear modulus increased, and the damping ratio decreased.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Tugen Feng ◽  
Yu Tang ◽  
Qiyenan Wang ◽  
Jian Zhang ◽  
Jian Song

In this paper, extensive resonant column tests were conducted to investigate dynamic responses of subsea sand-silt mixtures. The effects of confining pressure, mixture ratio, curing age, and cement content were evaluated. For the test condition considered in this study, the measured damping ratio is the smallest when the ratio of subsea sand to silt is in a range of 1.5 to 2.0. Moreover, unsolidified subsea sand-silt mixed at a ratio of 1.5 has almost the same maximum shear stiffness as the pure sand. For solidified subsea sand-silt mixture, cement can significantly increase the dynamic shear stiffness when the curing age is less than 14 days. However, the increase of the maximum dynamic shear stiffness is negligible when the curing age is longer than 14 days. When the cement content is 2%, the damping ratio of the solidified mixtures is very close to that of the unsolidified mixture. When the cement content is higher than 4%, the damping ratio of the solidified mixtures reduces significantly. This is mainly due to hydration reactions occurring in the solidified mixtures.


2012 ◽  
Vol 524-527 ◽  
pp. 459-465
Author(s):  
Jian Bin Xie ◽  
Wen Lian Liu ◽  
Lin Hua Shi ◽  
Guo Hai Zhang ◽  
Jie Zhang

In this paper, it has been studied that types and mechanical properties of tailings silt in Zhuziqing tailings dam based on the Zhuziqing tailings’ deposition characteristics, particles size distribution test, physical and mechanical properties test. Then it has been studied subsequently by the dynamic triaxial test, wave velocity test and standard penetration test for tailings silt that the dynamic characteristics, dynamic strength and vibration liquefaction of the tailing silt. Results show that the tailings silt in tailings pond is graded well. Under the condition of isotropic or anisotropic consolidation, dynamic shear modulus of tailings silt increase as the dynamic shear strain decreasing and increase as the increase of confining pressure or consolidation ratio. But the variation law on damping ratio of tailings silt is just opposite to that of dynamic shear modulus. Results also show that there is more liquefied possibility over the seventh sub-dam in the tailings dam, and the liquefied possibility position locates at the place from new sub-dam to deposited beach in tailing pond.


2013 ◽  
Vol 405-408 ◽  
pp. 1957-1960 ◽  
Author(s):  
Xin Lin Wan ◽  
Dao Lin Yang

The article through to free vibration column experiment research to soft soil of Binhu new district of Hefei, The data and curves are given for four types of soil dynamic shear modulus and damping ratio with shear strain and draw rules of different size of confining pressure on the dynamic shear modulus and damping ratio of soil. For hefei binhu new area soft soil of the physical and mechanical characteristics, select the optimal soft foundation treatment scheme, practical design calculation model is set up, and perfect the construction technology measures, the article has some reference value.


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