scholarly journals Impact of Cyclic Loading on Shakedown in Cohesive Soils—Simple Hysteresis Loop Model

2020 ◽  
Vol 10 (6) ◽  
pp. 2029 ◽  
Author(s):  
Andrzej Głuchowski ◽  
Wojciech Sas
Keyword(s):  
Cyclic Loading ◽  
Hysteresis Loop ◽  
Permanent Deformation ◽  
Triaxial Tests ◽  
Engineering Practice ◽  
Cohesive Soils ◽  
Loop Model ◽  
Deformation Characteristics ◽  
Cyclic Triaxial ◽  
Permanent Strain

The objective of this study is to characterize the permanent deformations and to present a mathematical model that enables the prediction of permanent strain during cyclic loading. First, laboratory cyclic triaxial tests are conducted on sandy silty clay samples to gather the data concerning the permanent deformation characteristics. The article discusses the shakedown theory and abation phenomena, and we present the Simple Hysteresis Loop Model (SHLM) based on the stress-controlled test results. The determined permanent deformation properties are a base for the development of SHLM parameters. The presented model is capable of accurately predicting the permanent deformation characteristics based on the derived parameters from the static tests. The SHLM connects the stress–strain and stiffness properties of cohesive soil, which gives it a great advantage to use it in engineering practice. The derived model was verified based on ex–post comparison to performed cyclic triaxial test. The developed SHLM mean absolute percentage error is equal to 12.18%, which indicates that the developed SHLM has desirable accuracy in the prediction of permanent strain properties in compacted cohesive soils.

scholarly journals An Evaluation of the Resilient Modulus and Permanent Deformation of Unbound Mixtures of Granular Materials and Rubber Particles from Scrap Tyres to Be Used in Subballast Layers

2016 ◽  
Author(s):  
Carlos Hidalgo Sgnes
Keyword(s):  
Granular Materials ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Waste Material ◽  
Triaxial Tests ◽  
Rubber Content ◽  
Cyclic Triaxial ◽  
Cyclic Triaxial Tests ◽  
Vibration Attenuation ◽  
Rubber Particles

Over the last years rubber from scrap tyres has been reused in different civil works such as road embankments and railway platforms due to its resilient properties, low degradation and vibration attenuation. Unfortunately, this issue is still scarce. For instance, in Spain about 175.000 tonnes of scrap tyres were collected in 2014, of which only 0.6% were reused in civil works. Aiming to contribute to the reutilisation of large quantities of this waste material, this paper focuses on the analysis of unbound mixtures of granular materials with different percentages of rubber particles to be used as subballast layers. Mixtures are tested under cyclic triaxial tests so as to obtain their resilient modulus and evaluate their permanent deformations. It is found that as the rubber content increases, the resilient modulus decreases and the permanent deformation increases. Taking into account the usual loads transmitted to the subballast layer, the optimum rubber content that does not compromise the behaviour of the mixture is set in a range between 2.5% and 5% in terms of weight.DOI: http://dx.doi.org/10.4995/CIT2016.2016.4231

scholarly journals Relationship between monotonic and cyclic behavior of saturated soft clay in undrained triaxial compression tests

2021 ◽  
Author(s):  
Tingyu Wu ◽  
Jie Han ◽  
Yuanqiang Cai ◽  
Lin Guo ◽  
Jun Wang
Keyword(s):  
Cyclic Loading ◽  
Triaxial Compression ◽  
Soft Clay ◽  
Cyclic Behavior ◽  
Triaxial Tests ◽  
Engineering Practice ◽  
Compression Tests ◽  
Cyclic Tests ◽  
Saturated Soft Clay ◽  
Triaxial Compression Tests

Cyclic loading-induced deformation of soil is a common problem in the engineering practice. In the current practice, however, monotonic triaxial tests are more commonly used in the practice, due to the availability of apparatus and ease of operation. Thus, it will be very useful and practical if the monotonic triaxial tests can be used to evaluate the behavior of soil under cyclic loading. This study aims to find an explicit relationship between monotonic and cyclic behavior of saturated soft clay. Six monotonic and nine cyclic triaxial compression tests were conducted on undisturbed saturated soft clay under an undrained condition. The test results showed that the monotonic and cyclic tests shared the same stress-strain surface in a three-dimensional space p^'-q-ε_a. It is also found possible to evaluate the effective stress states of cyclic tests at two specific numbers of cycles, using corresponding monotonic tests. Based on these two findings, a simple procedure was then proposed to predict the peak axial strain for the saturated soft clay under different cyclic loadings based on the monotonic tests and only one cyclic test, which was further verified against more test data from the previous literature.

Resilient and permanent deformation of unsaturated unbound granular materials under cyclic loading by the large-scale triaxial tests

2020 ◽  
Vol 15 (12) ◽  
pp. 3343-3356
Author(s):  
Chuan Gu ◽  
Yun Zhan ◽  
Jun Wang ◽  
Yuanqiang Cai ◽  
Zhigang Cao ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Granular Materials ◽  
Large Scale ◽  
Permanent Deformation ◽  
Triaxial Tests ◽  
Unbound Granular Materials

scholarly journals Deformation Characteristics of Soft Marine Soil Tested under Cyclic Loading with Low Frequency

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yu Lu ◽  
Wenbin Fu ◽  
Danxuan Xue
Keyword(s):  
Cyclic Loading ◽  
Pore Pressure ◽  
High Stress ◽  
Low Frequency ◽  
Load Level ◽  
Triaxial Tests ◽  
Deformation Characteristics ◽  
Confining Stress ◽  
The Difference ◽  
Marine Soil

Soft marine soil which could be found widely at the coastal and offshore areas is usually associated with high settlement and instability, especially under cyclic loading. Many research studies have been conducted on its deformation characteristics under the cyclic loading with high frequency, whereas few works have been reported on that under the low-frequency cyclic loading which largely existed in engineering. In this work, a comprehensive series of undrained triaxial tests under cyclic loading with low frequency was conducted to investigate the deformation characteristics of soft marine soil. The results demonstrate that soil specimens accumulate plastic deformation and pore pressure under cyclic loading. Specimens tested under conditions such as high confining stress, high-stress ratio, and long cyclic period generally reveal higher deformation and pore pressure. Meanwhile, the rectangular wave presents the largest contribution to plastic strain and pore pressure, followed by the trapezoidal and triangular waves, respectively, whereas the difference between the various waves decreased gradually with the increasing load level and cyclic period. The undisturbed specimens displayed lower deformations and pore pressures than the reconstructed specimens, whereas the differences are not significant when the confining stress is much higher than the structural yield stress. Furthermore, an empirical model for predicting the evolution of pore pressure is proposed and then validated against the experimental data in both this work and the literature.

scholarly journals Undrained Cyclic Laboratory Behavior of Sandy Soils

Geosciences ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 512 ◽  
Author(s):  
Francesco Castelli ◽  
Antonio Cavallaro ◽  
Salvatore Grasso ◽  
Valentina Lentini
Keyword(s):  
Cyclic Loading ◽  
Seismic Retrofitting ◽  
Coarse Grained ◽  
Triaxial Tests ◽  
Cyclic Triaxial ◽  
Cyclic Triaxial Tests ◽  
Residual Performance ◽  
Definition Of

The complex cyclic shear stress path experienced by the soil during an earthquake, which could also induce liquefaction phenomena, can be approximated in the laboratory only by using sophisticated testing apparatuses. Cyclic triaxial tests have been widely used, especially for coarse grained soils, as in this study. In the framework of the design for the seismic retrofitting of the ‘‘Ritiro viaduct’’ foundations along the A20 motorway connecting Messina with Palermo (Italy), a soil liquefaction study was also carried out. With this aim, a detailed geological and geotechnical characterization of the area was performed by in situ and laboratory tests, including seismic dilatometer Marchetti tests (SDMTs), the combined resonant column (RCT) and cyclic loading torsional shear tests (CLTSTs), and undrained cyclic loading triaxial tests (CLTxTs). In particular, the paper presents the results of cyclic triaxial tests carried out on isotropically consolidated specimens of a sandy soil. The seismic retrofitting works include the reinforcement of the foundation and replacement of the decks with newly designed type and structural schemes, mixed steel, and concrete with continuous girder. During the investigation, data were acquired for the characterization of materials, for the definition of degradation phenomena with the relative identification of possible causes, and for the estimation of the residual performance characteristics of the building. The structural campaign of investigations necessary to determine all of the key parameters useful for a correct definition of the residual performance capabilities of the work was divided into two phases: One in situ and one in the laboratory.

Comparisons of deformation characteristics of rockfill materials using monotonic and cyclic loading laboratory tests and in situ tests

1994 ◽  
Vol 31 (2) ◽  
pp. 162-174 ◽  
Author(s):  
Nario Yasuda ◽  
Norihisa Matsumoto
Keyword(s):  
Cyclic Loading ◽  
Laboratory Test ◽  
Laboratory Tests ◽  
Shear Test ◽  
Triaxial Tests ◽  
Deformation Characteristics ◽  
Simple Shear Test ◽  
Small Strains ◽  
Rockfill Materials

The deformation characteristics of rockfill materials at very small strains were investigated by comparing the results of monotonic and cyclic loading laboratory tests with geophysical P- and S-wave logging data from the field. Using a precision linear variable differential transformer for displacement, the elastic moduli of rockfill materials at very small strains were measured in monotonic and cyclic loading triaxial tests. The laboratory test results agreed well with the field results. The shear moduli of rockfill materials from both a monotonic loading torsional simple shear test and a cyclic loading torsional simple shear test also showed good correspondence. Furthermore, the shear modulus predicted from the in situ shear wave tests in rockfill dams corresponded reasonably well with the modulus in the large-scale triaxial tests in the laboratory. Key words : deformation characteristics, embankment dams, rockfill materials, laboratory test, in situ test.

Sign in / Sign up

Export Citation Format

Share Document