scholarly journals Modelling of Rock Joints Interface under Cyclic Loading

2020 ◽  
Vol 42 (1) ◽  
pp. 36-47 ◽  
Author(s):  
Jan Maciejewski ◽  
Sebastian Bąk ◽  
Paweł Ciężkowski
Keyword(s):  
Cyclic Loading ◽  
Normal Load ◽  
Shear Bands ◽  
Yield Function ◽  
Rock Joints ◽  
Response Analysis ◽  
Material Interface ◽  
Cyclic Shear ◽  
Dilatancy Effect ◽  
Cyclic Shear Test

AbstractThe problem of numerical simulation of the material interface response under monotonic and cyclic loading is of fundamental scientific and engineering importance. In fact, such interfaces occur in most engineering and geotechnical structures. The present work is devoted to the deformational response analysis of contact interfaces under monotonic and cyclic loads. The class of materials includes rock and structural joints, soil structure interfaces, masonry and cementitious joints, localized shear bands and so on.The aim of the proposed model is to simulate the cyclic shear test under constant normal load. The associated dilatancy effect is associated with the configurational effects of asperity interaction or dilatancy of wear debris layer. The large primary asperities are assumed as responsible for interfacial dilation and small size asperities as governing frictional sliding and hysteresis response. The elliptic loading yield function is assumed to translate and rotate during progressive or reverse loading events. The model formulation is discussed and confronted with experimental data.

scholarly journals Investigation on Acoustic Emission Kaiser Effect and Frequency Spectrum Characteristics of Rock Joints Subjected to Multilevel Cyclic Shear Loads

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Zhiqiang Hou ◽  
Changhong Li ◽  
Zhengyang Song ◽  
Yonggang Xiao ◽  
Chen Qiao ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Cyclic Loading ◽  
Frequency Spectrum ◽  
Rock Joints ◽  
Displacement Curve ◽  
Kaiser Effect ◽  
Cyclic Shear ◽  
Shear Damage ◽  
Spectrum Characteristics ◽  
Felicity Ratio

Rock joints have obvious acoustic emission (AE) Kaiser effect and Felicity effect under multilevel cyclic shear conditions. The TFD-20H/50J rock shear apparatus was used to carry out cyclic loading and unloading joint shear tests, and the acoustic emission parameters and frequency spectrum characteristics of the whole shearing process were analyzed. The results show that, under the cyclic loading, the shear stress-displacement curve forms several cyclic hysteresis loops, and the number of loops increases with the increase of normal stress. With the cycles increase, the shear damage gradually increases, and the Felicity ratio gradually decreases. The Felicity ratio at the final shear failure moment is about 0.94~0.99. The ratio of the RA value (rise time/amplitude) and the average frequency value (RA-AF) is used to classify the cracking mode of the joint sample. There are two AE crack signal types (tensile type and shear type) during shear damage. The peak frequency is displayed as high, medium, and low three frequency bands, which are distributed in the range of 0~35 kHz, 35~122 kHz, and 122~300 kHz, respectively. Both low-frequency and high-frequency signals account for less than 10%, and medium-frequency signals account for more than 90%. The research of the AE monitoring signals of multilevel shear behaviors can help understand the shear-friction mechanisms of rock joints.

TIME TO THE END OF PRIMARY CONSOLIDATION (EOP) OF SOFT CLAYEY SOILS: CONCERNING THE EFFECT OF ATTERBERG’S LIMIT AND CYCLIC LOADING HISTORY

2019 ◽  
Vol 128 (2B) ◽  
pp. 29-41
Author(s):  
Trần Thanh Nhàn
Keyword(s):  
Cyclic Loading ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Clayey Soils ◽  
Loading History ◽  
Cyclic Shear ◽  
Wide Range ◽  
Primary Consolidation ◽  
Time Required

In order to observe the end of primary consolidation (EOP) of cohesive soils with and without subjecting to cyclic loading, reconstituted specimens of clayey soils at various Atterberg’s limits were used for oedometer test at different loading increments and undrained cyclic shear test followed by drainage with various cyclic shear directions and a wide range of shear strain amplitudes. The pore water pressure and settlement of the soils were measured with time and the time to EOP was then determined by different methods. It is shown from observed results that the time to EOP determined by 3-t method agrees well with the time required for full dissipation of the pore water pressure and being considerably larger than those determined by Log Time method. These observations were then further evaluated in connection with effects of the Atterberg’s limit and the cyclic loading history.

A New Direct Shear Apparatus for Rock Joints Specialized in Cyclic Loading

2021 ◽  
Author(s):  
Zhen Cui ◽  
Qian Sheng ◽  
Mao-chu Zhang ◽  
Jun-feng Cao ◽  
Xian-cheng Mei ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Rock Joints ◽  
Direct Shear ◽  
Direct Shear Apparatus

Frictional complete contacts subject to shear and bulk tension

2008 ◽  
Vol 222 (12) ◽  
pp. 2301-2309 ◽  
Author(s):  
N Banerjee ◽  
D Dini ◽  
D A Hills
Keyword(s):  
Normal Load ◽  
Cyclic Shear ◽  
Edge Angle ◽  
Subsequent Application ◽  
Constant Normal Load

This paper provides a set of ‘maps’ showing the response of three example frictional complete contacts (with edge angle of 60°, 90°, and 120°) subject to a constant normal load and the subsequent application of cyclic shear and bulk tension, the latter present in only one body. The maps define the region of full adhesion, the nature of violations, and conditions under which they arise.

A Comparative Study of the Response of Double Shearing and Hypoplastic Models

2002 ◽  
Author(s):  
Huaning Zhu ◽  
Morteza M. Mehrabadi ◽  
Mehrdad Massoudi
Keyword(s):  
Cyclic Loading ◽  
Mechanical Response ◽  
Constitutive Relations ◽  
Constitutive Models ◽  
Shear Loading ◽  
Biaxial Compression ◽  
Finite Element Program ◽  
Cyclic Shear ◽  
Hypoplastic Model ◽  
Element Program

The principal objective of this paper is to compare the mechanical response of a double shearing model with that of a hypoplastic model under biaxial compression and under cyclic shear loading. As the origins and nature of these two models are completely different, it is interesting to compare the predictions of these two models. The constitutive relations of the double shearing and the hypoplastic models are implemented in the finite element program ABACUS/Explicit. It is found that the hypoplastic and the double shearing constitutive models both show strong capability in capturing the essential behavior of granular materials. In particular, under the condition of non-cyclic loading, the stress ratio and void ratio predictions of the double shearing and the hypoplastic models are relatively close, while under the condition of cyclic loading, the predictions of these models are quite different. It is important to note that in the double shearing model employed in this comparison the shear rates on the two slip systems are assumed to be equal. Hence, the conclusions derived in this comparison pertain only to this particular double shearing model. Similarly, the hypoplasticity model considered here is that proposed by Wu, et al. [30] and the conclusions reached here pertain only to this particular hypoplasticity model.

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