Experimental Investigation into Cyclic Shear Behaviors in the Interface Between Steel and Crushed Mudstone Particles

2021 ◽  
pp. 036119812110621
Author(s):  
Yue Liang ◽  
Rifeng Xia ◽  
Zeyu Liu ◽  
Chen Ma ◽  
Hongjie Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Construction Projects ◽  
Large Scale ◽  
Steel Tube ◽  
Lateral Loads ◽  
Cyclic Shear ◽  
Constant Stiffness ◽  
New Apparatus ◽  
The Stability ◽  
Shear Behaviors

In the waterway construction projects of the upper streams of the Yangtze River, crushed mudstone particles are widely used to backfill the foundations of the rock-socketed concrete-filled steel tube (RSCFST) pile. The mudstone particles are prone to being crushed, which influences the mechanical properties of the soil and the interface between the soil and the steel cased on the RSCFST pile. The crushing of the particles will be aggravated by reciprocating shear of the interface when the pile experiences repeating lateral loads. The reciprocating shear of the interface may, therefore, weaken the bearing capacity of the pile. In this study, we develop a new apparatus to study the mechanical properties of the steel–soil interface under a reciprocating shear condition. With this apparatus, a set of large-scale direct shear experiments are carried out with two different boundary conditions, that is, a constant stress boundary and a constant stiffness boundary, respectively. Comparative experiments and parallel experiments are carried out to study the physical properties of steel–mudstone particle interface and the stability of the apparatus. Parallel experiments show that the instrument has good stability. The comparative experiment results also reveal the differences of the shear behaviors of the interface under two conditions. Analysis of the experiment results shows that the normal stiffness condition is closer to the real boundary condition when the soil–steel interface is cyclically sheared. The particle crushing and the attenuation of normal stress is the main reason causing the degrading of the interface.

scholarly journals Estimation of Optimum Moisture Content and Maximum Dry Unit Weight of Fine-Grained Soils using Numerical Methods

2021 ◽  
Vol 18 (16) ◽  
Author(s):  
Armand Augustin FONDJO ◽  
Elizabeth THERON ◽  
Richard P. RAY
Keyword(s):  
Soil Compaction ◽  
Construction Projects ◽  
Large Scale ◽  
Unit Weight ◽  
Fine Grained ◽  
Dry Unit Weight ◽  
Optimum Water Content ◽  
Predicted Values ◽  
The Stability ◽  
Optimum Water

Soil compaction is one of the basic engineering techniques, which is carried out to guarantee the stability of soils dependent on specified strength. Nonetheless, in large-scale construction projects, the estimation of compaction features required tremendous effort and time that can be saved utilizing empirical relationships at the initial phases. It becomes critical to develop models to predict the compaction features, namely the maximum dry unit weight (γdmax) and optimum water content (WOP). This article attempts to develop models to predict the γdmax and WOP of fine-grained clay soils. Geotechnical tests such as grain size distribution, Atterberg limits, specific gravity, and proctor compaction tests are performed to assess soil samples' physical and hyro-mechanical characteristics. Multivariate analysis is conducted using MINITAB 18 software to develop the predictive models. The validation process of developed models includes the determination coefficient, probability value (p-value), comparison of the predicted values with experimental values, comparison of the models proposed in this study with other existing models found in the recent literature, and employing a different soil data set. The predicted values obtained from the models proposed in this research project are more accurate than other models developed recently. The proposed models estimate the compaction features of fine-grained clay soils with acceptable precision. HIGHLIGHTS Soil compaction is one of the basic engineering techniques perform to guarantee the stability of soils dependent on specified strength In large-scale construction projects, the estimation of compaction parameters required tremendous effort and time that can be saved utilizing empirical relationships at the initial phases This study has developed semi-empirical models to predict the compaction parameters (maximum dry unit weight and optimum water content) of fine-grained soils GRAPHICAL ABSTRACT

EXPERIMENTAL ANALYSIS ON THE MECHANICAL PROPERTIES OF SOIL-ROCK MIXED FILLERS WITH DIFFERENT ROCK CONTENTS ON A HIGH EMBANKMENT

10.6036/10235 ◽  
2021 ◽  
Vol 96 (5) ◽  
pp. 478-483
Author(s):  
YANQING ZHANG ◽  
HONGJUN JING ◽  
JUNYI DAI
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Volumetric Strain ◽  
Strain Curve ◽  
Mountainous Area ◽  
Stress Strain ◽  
Study Results ◽  
The Stability ◽  
Chang Model ◽  
Properties Of Soil

The mechanical properties of soil-rock mixed filler are the key factors influencing the high rockfill embankment stability. However, they remain unclear, given the complexity of soil-rock mixed filler structure. To analyze the stability of high rockfill embankment in the construction and operation phases, under the engineering background of a high rockfill embankment with a filling height of 50.6 m in the national highway 316 project within the Qinba mountainous area in China, a series of large-scale triaxial consolidated drained shear tests were performed on two soil-rock mixed fillers with 40% and 70% rock contents. Their stress-strain relation, deformation, and strength characteristics were observed. The applicability of Duncan-Chang model was also determined on the basis of the above tests. Results demonstrate that the stress-strain curve and volumetric strain of the filler with 40% rock content are strain hardening type and shear shrinkage type. The filler with 70% rock content has a weak strain softening, and its volumetric strain is first shear shrinkage and then shear dilation. The filler with 70% rock content has larger peak and critical frictional angles than the filler with 40% rock content. The tangential Poisson's ratios of the E-B and E-? models are obtained. The former can approximately reflect the volumetric strain characteristics of the filler with 40% rock content. The latter can approximately reflect those of the filler with 70% rock content. Yet, both models fail to describe the influence of confining pressure on the volumetric strain. The study results provide a reference for the stability analysis of high rockfill embankment engineering and provide parameters for constructing the constitutive model of soil-rock mixed fillers. Keywords: high embankment; soil-rock mixed filler; large-scale triaxial shear test; deformation characteristics; Duncan-Chang model

scholarly journals Review of Research on Physical and Mechanical Properties and Engineering Application of Metal Tailings

2022 ◽  
Vol 2148 (1) ◽  
pp. 012059
Author(s):  
Shengfu Wang ◽  
Lechen Yan ◽  
Kaixi Xue ◽  
Liang Lv ◽  
Dongjie Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Building Materials ◽  
Engineering Application ◽  
Physical And Mechanical Properties ◽  
Future Research ◽  
Tailing Dams ◽  
The Stability ◽  
Processing And Storage ◽  
And Storage

Abstract Processing and storage requirements for metal residues are becoming stricter to achieve the carbon neutralization target. The physical and mechanical properties of tailings affect the stability of tailing dams. Metal tailings can be used as secondary resources, and it is easy to pollute the environment under poorly managed conditions. Therefore, it is necessary and urgent to reuse these deposits such as iron tailings, copper tailings, zinc tailings et al. This article discusses the current research on the mechanical properties of metal tailings and its engineering application. Based on previous research, it is pointed out that there still needs more attention on the mechanical properties of metal tailing sands, especially under different conditions like dry-wet, freeze-thaw, dynamic loads and large-scale application. In the future, research on the filling of metal tailings as roadbed and new building materials will be one of the directions to solve the problem of tailing pond accumulation.

scholarly journals Prediction of Surface Subsidence Extension due to Underground Caving: A Case Study of Hemushan Iron Mine in China

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Hangxing Ding ◽  
Song Chen ◽  
Shuai Chang ◽  
Guanghui Li ◽  
Lei Zhou
Keyword(s):  
Rock Mass ◽  
Analytical Model ◽  
Construction Projects ◽  
Large Scale ◽  
Surrounding Rock ◽  
Surface Subsidence ◽  
Proposed Model ◽  
Iron Mine ◽  
Subsidence Zone ◽  
The Stability

Underground caving can potentially lead to large-scale surface destruction. To test the safety conditions of the surface construction projects near the circular surface subsidence zone in the Hemushan Iron Mine, this paper proposes an analytical model to analyze the stability of the cylindrical caved space by employing the long-term strength of the surrounding rock mass, the in situ stress, and the impact of caved materials as inputs. The proposed model is valid for predicting the orientation and depth where rock failure occurs and for calculating the maximum depth of the undercut, above which the surrounding rock mass of the caved space can remain stable for a long duration of time. The prediction for the Hemushan Iron Mine from the proposed model reveals that the construction projects can maintain safe working conditions, and such prediction is also demonstrated by the records from Google Earth satellite images. This means that the proposed model is valid for conducting such analysis. Additionally, to prevent rock failure above the free surface of caved materials, backfilling the subsidence zone with waste rocks is suggested, and such a measure is implemented in the Hemushan Iron Mine. The monitoring results show that this measure contributes to protecting the surrounding wall of the caved space from large-scale slip failure. The contribution of this work not only provides a robust analytical model for predicting the stability of rock around a cylindrical caved space but also introduces employable measures for mitigating the subsequent extension of surface subsidence after vertical caving.

An analysis of the transport properties and mechanical stability of rapidly solidified Al-Sb alloy

2015 ◽  
Vol 10 (2) ◽  
pp. 2663-2681
Author(s):  
Rizk El- Sayed ◽  
Mustafa Kamal ◽  
Abu-Bakr El-Bediwi ◽  
Qutaiba Rasheed Solaiman
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Melt Spinning ◽  
Elastic Moduli ◽  
Mechanical Stability ◽  
Microstructural Analysis ◽  
Alloy System ◽  
Antimony Content ◽  
The Stability ◽  
Rapidly Solidified

The structure of a series of AlSb alloys prepared by melt spinning have been studied in the as melt–spun ribbons  as a function of antimony content .The stability  of these structures has  been  related to that of the transport and mechanical properties of the alloy ribbons. Microstructural analysis was performed and it was found that only Al and AlSb phases formed for different composition.  The electrical, thermal and the stability of the mechanical properties are related indirectly through the influence of the antimony content. The results are interpreted in terms of the phase change occurring to alloy system. Electrical resistivity, thermal conductivity, elastic moduli and the values of microhardness are found to be more sensitive than the internal friction to the phase changes. 

A New Large Scale Technic for Quantitative Recovery of Enteroviruses by Adsorption on Suspended Glass Powder. Application to Surface and Drinking Waters of the Paris Area

1982 ◽  
Vol 14 (4-5) ◽  
pp. 281-290
Author(s):  
Ph Vilaginès ◽  
B Sarrette ◽  
C Danglot ◽  
R Vilaginès
Keyword(s):  
River Water ◽  
Surface Waters ◽  
Large Scale ◽  
Glass Powder ◽  
Virus Concentration ◽  
Drinking Waters ◽  
Paris Area ◽  
New Apparatus ◽  
Quantitative Recovery

The aim of this work is to describe a new and inexpensive glass powder apparatus allowing virus concentration from 500 1 sample of water (10). Its efficiency was determined by analysis of drinking and surface waters preinoculated by Poliovirus. The detection of viruses from river water is compared when 500 1 (new apparatus) or 10 1 (preceeding apparatus) (7) are processed. The proposed new 500 1 apparatus allowed the recuperation of viruses in 100 % of the analysed samples the 10 1 one allowing their recuperation in only 50 % samples. This method was applied to the virus determination in the surface and drinking waters of the Paris area.

Control of humping phenomenon and analyzing mechanical properties of Al–Si wire-arc additive manufacturing fabricated samples using cold metal transfer process

2021 ◽  
pp. 095440622199840
Author(s):  
Yashwant Koli ◽  
N Yuvaraj ◽  
Aravindan Sivanandam ◽  
Vipin
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Heat Input ◽  
Large Scale ◽  
High Deposition Rate ◽  
Bead Geometry ◽  
Layer By Layer ◽  
Cold Metal Transfer ◽  
Geometrical Shapes ◽  
Wire Arc Additive Manufacturing

Nowadays, rapid prototyping is an emerging trend that is followed by industries and auto sector on a large scale which produces intricate geometrical shapes for industrial applications. The wire arc additive manufacturing (WAAM) technique produces large scale industrial products which having intricate geometrical shapes, which is fabricated by layer by layer metal deposition. In this paper, the CMT technique is used to fabricate single-walled WAAM samples. CMT has a high deposition rate, lower thermal heat input and high cladding efficiency characteristics. Humping is a common defect encountered in the WAAM method which not only deteriorates the bead geometry/weld aesthetics but also limits the positional capability in the process. Humping defect also plays a vital role in the reduction of hardness and tensile strength of the fabricated WAAM sample. The humping defect can be controlled by using low heat input parameters which ultimately improves the mechanical properties of WAAM samples. Two types of path planning directions namely uni-directional and bi-directional are adopted in this paper. Results show that the optimum WAAM sample can be achieved by adopting a bi-directional strategy and operating with lower heat input process parameters. This avoids both material wastage and humping defect of the fabricated samples.

Sign in / Sign up

Export Citation Format

Share Document