scholarly journals Rock strength analysis due to discontinuity and grouting

2020 ◽  
Vol 2 (1) ◽  
pp. 29-36
Author(s):  
Nur Alam Syah Rahman ◽  
Ganda Marihot Simangunsong ◽  
Irwandi Arif
Keyword(s):  
Shear Strength ◽  
Rock Strength ◽  
Failure Criteria ◽  
The Other ◽  
Strength Analysis ◽  
Positive Contribution ◽  
Negative Contribution ◽  
Artificial Joints ◽  
Rock Reinforcement ◽  
Stone Type

Instability on rock, one of many factors caused by joint. Decreased of rock strength occurred inline with existence a number of joints. Poor rock have a large number of joints. Therefore rock reinforcement such as grouting can be one of the solution. This research conducted on artificial sample Moldano Tara (dental stone type III). It had been given artificial joints with orientation 60o from axial and frequency 1 till 2.  Furthermore, grout material with composition 4C;5W had been injected on joint and cured in 28 days. Triaxial test are done in all samples intact, jointed and grouted and its been analyzed with Mohr-Coulomb and Hoek Brown failure criteria. It is found,  joint given negative contribution on shear strength, declining 65,75% and 73,48%, whereas on UCS declined 46,85% dan 56,19%. On the other hand, grouting had been given positive contribution on shear strength, increasing 166,15% and 188,07%, while UCS increased 46,60% and 60,92%

CLC 18.10LN

Alloy Digest ◽  
2006 ◽  
Vol 55 (1) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
High Temperature ◽  
Austenitic Stainless Steel ◽  
Stainless Steels ◽  
The Other ◽  
Low Carbon ◽  
Good Corrosion Resistance ◽  
Temperature Performance

Abstract CLC 18.10LN is an austenitic stainless steel with 18% Cr, 9.5% Ni, and 0.14% N to provide good corrosion resistance at strengths above the other low-carbon stainless steels. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and shear strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, machining, and joining. Filing Code: SS-950. Producer or source: Industeel USA, LLC.

On Slip Inception and Static Friction for Smooth Dry Contact

2014 ◽  
Vol 81 (12) ◽  
Author(s):  
Xi Shi
Keyword(s):  
Shear Strength ◽  
Contact Area ◽  
Material Properties ◽  
Static Friction ◽  
Friction Model ◽  
Interfacial Bonding ◽  
The Other ◽  
Material Failure ◽  
Bonding Failure ◽  
Dry Contact

Slip inception mechanism is very important for modeling of static friction and understanding of some experimental observations of friction. In this work, slip inception was treated as a local competence of interfacial bonding failure and weaker material failure. At any contacting point, if bond shear strength is weaker than softer material shear strength, slip inception is governed by interfacial bonding failure. Otherwise, it is governed by softer material failure. Considering the possible co-existence of these two slip inception mechanisms during presliding, a hybrid static friction model for smooth dry contact was proposed, which indicates that the static friction consists of two components: one contributed by contact area where bonding failure is dominant and the other contributed by contact area where material failure is dominant. With the proposed static friction model, the effects of contact pressure, the material properties, and the contact geometry on static friction were discussed.

Ramie fiber reinforced composites with flame retardant structure design: flammability, smoke suppression, and mechanical properties

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chenkai Zhu ◽  
Lei Nie ◽  
Xiaofei Yan ◽  
Jiawei Li ◽  
Dongming Qi
Keyword(s):  
Shear Strength ◽  
Iron Oxide ◽  
Heat Release ◽  
Flame Retardant ◽  
Interlaminar Shear Strength ◽  
Smoke Suppression ◽  
Strength Analysis ◽  
Ramie Fiber ◽  
Composite Surface ◽  
Interlaminar Shear

Abstract In this work, the structure of composite was designed as Core Stack and Surface Stack, which was treated with the expandable graphite (EG) and metal oxides such as iron oxide (IO), hydroxyapatite (HA), and aluminum tri-hydroxide (ATH). The mechanical performance of composites was characterized via flexural performance and interlaminar shear strength analysis. The flame retardance and smoke suppression of composite was explored in detail by LOI, UL-94, and cone calorimeter test. The findings presented that flexural properties of composites were observed to decrease due to delamination of surface stack, whilst no significant effect on interlaminar shear strength. In comparison with control composite, the loading of metal oxide into composite Surface Stack led to the reduction of peak heat release rate, total heat release, and fire growth index effectively. Moreover, the remarkable decrease in total smoke production could be observed due to the addition of iron oxide and the flame retardant mechanism was discussed. This study was the preliminary exploration of composite with flame retardant design which could be potential solution to improve flame retardancy and smoke suppression of composite with better mechanical structure preservation.

scholarly journals Determination of reinforcing bars for tests of hollow core slabs with continuity

2013 ◽  
Vol 6 (6) ◽  
pp. 903-932
Author(s):  
A. P. Santos ◽  
M. A. Ferreira ◽  
R. C. Carvalho ◽  
L. M. Pinheiro
Keyword(s):  
Shear Strength ◽  
The Other ◽  
Hollow Core ◽  
Reinforcing Bars ◽  
Simply Supported ◽  
Resistance Moment ◽  
Hollow Core Slab ◽  
Maximum Shear Strength

The structural designs of floors formed by hollow core slabs usually consider these as simply-supported slabs. In recent years there have been project changes and hollow core slabs with continuity are widely used. The objective of this study is to suggest a way to calculate the reinforcement bars to be used in tests with continuity provided by a structural topping. Thus, this paper presents a method based on the maximum positive resistance moment and maximum shear strength of a hollow core slab. The method is applied to a test in hollow core slab specimens which have the following dimensions: 2 m width, 6 m long, and 21 cm high. The results indicated that the method was satisfactory to the performed test, and can therefore be applied to the other test configurations or even designs.

scholarly journals Impacts of AMSU-A, MHS and IASI data assimilation on temperature and humidity forecasts with GSI–WRF over the western United States

2015 ◽  
Vol 8 (10) ◽  
pp. 4231-4242 ◽  
Author(s):  
Y. Bao ◽  
J. Xu ◽  
A. M. Powell Jr. ◽  
M. Shao ◽  
J. Min ◽  
...  
Keyword(s):  
United States ◽  
Data Assimilation ◽  
Lower Troposphere ◽  
Western United States ◽  
Observation Data ◽  
Positive Contribution ◽  
Negative Contribution ◽  
Infrared Observation ◽  
Forecast Bias ◽  
Infrared Data

Abstract. Using NOAA's Gridpoint Statistical Interpolation (GSI) data assimilation system and NCAR's Advanced Research WRF (Weather Research and Forecasting) (ARW-WRF) regional model, six experiments are designed by (1) a control experiment (CTRL) and five data assimilation (DA) experiments with different data sets, including (2) conventional data only (CON); (3) microwave data (AMSU-A + MHS) only (MW); (4) infrared data (IASI) only (IR); (5) a combination of microwave and infrared data (MWIR); and (6) a combination of conventional, microwave and infrared observation data (ALL). One-month experiments in July 2012 and the impacts of the DA on temperature and moisture forecasts at the surface and four vertical layers over the western United States have been investigated. The four layers include lower troposphere (LT) from 800 to 1000 hPa, middle troposphere (MT) from 400 to 800 hPa, upper troposphere (UT) from 200 to 400 hPa, and lower stratosphere (LS) from 50 to 200 hPa. The results show that the regional GSI–WRF system is underestimating the observed temperature in the LT and overestimating in the UT and LS. The MW DA reduced the forecast bias from the MT to the LS within 30 h forecasts, and the CON DA kept a smaller forecast bias in the LT for 2-day forecasts. The largest root mean square error (RMSE) is observed in the LT and at the surface (SFC). Compared to the CTRL, the MW DA produced the most positive contribution in the UT and LS, and the CON DA mainly improved the temperature forecasts at the SFC. However, the IR DA gave a negative contribution in the LT. Most of the observed humidity in the different vertical layers is overestimated in the humidity forecasts except in the UT. The smallest bias in the humidity forecast occurred at the SFC and in the UT. The DA experiments apparently reduced the bias from the LT to UT, especially for the IR DA experiment, but the RMSEs are not reduced in the humidity forecasts. Compared to the CTRL, the IR DA experiment has a larger RMSE in the moisture forecast, although the smallest bias is found in the LT and MT.

scholarly journals Strength Theory Model of Unsaturated Soils with Suction Stress Concept

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Pan Chen ◽  
Changfu Wei ◽  
Jie Liu ◽  
Tiantian Ma
Keyword(s):  
Shear Strength ◽  
Unsaturated Soils ◽  
Theory Model ◽  
Strength Analysis ◽  
New Model ◽  
Suction Stress ◽  
Strength Change ◽  
Stability Of Slopes ◽  
Moisture State ◽  
The Stability

A theoretical model is developed for describing the strength property of unsaturated soils. The model is able to predict conveniently the strength changes of unsaturated soils undergoing repeated changes of water content. Suction stress is adopted in the new model in order to get the sound form of effective stress for unsaturated soils. The shear strength of unsaturated soils is dependent on its soil-moisture state based on the results of shear experiments. Hence, the parameters of this model are related tightly to hydraulic properties of unsaturated soils and the strength parameters of saturated soils. The predictive curves by the new model are coincident with experimental data that underwent single drying and drying/wetting cycle paths. Hence, hysteretic effect in the strength analysis is necessary to be considered to predict the change of shear strength of unsaturated soils that underwent drying/wetting cycles. Once the new model is used to predict the change of shear strength, lots of time could be saved due to avoiding heavy and complicated strength tests of unsaturated soils. Especially, the model can be suitable to evaluate the shear strength change of unsaturated soils and the stability of slopes experienced the drying/wetting cycles.

scholarly journals Influence of Local Tax and Zakat Infaq Maslahah Through to Regional Income (Overview of New Trends in Sustainable Development)

2019 ◽  
Vol 10 (4) ◽  
pp. 181
Author(s):  
Chablullah Wibisono ◽  
Indrayani ◽  
Iskandar Muda
Keyword(s):  
Structural Equation ◽  
Equation Modeling ◽  
Positive Contribution ◽  
Religious Leader ◽  
Negative Contribution ◽  
Regional Income ◽  
Local Taxes ◽  
Variable Pay ◽  
Variable Contribution ◽  
Regional Variable

Conditions Batam Island, Indonesia, economic growth declined from 5.4% in 2016, to under 2% percent in 2017, the disparity is difficult to increase revenue growth in Batam. It is necessary to look beyond the local revenues of local taxes, such as zakat and donation, to contribute to Maslahah through local revenue. Which research aimed at contributing to the Regional Income and Maslahah by using samples taken from the Department of Revenue at Batam City, Amil Zakat Agency (BAZ), Indonesia Religious Leader (MUI), Public Welfare with respondents 190. This study used software AMOS version 23 with Structural Equation Modeling (SEM). The result shows that the variable contribution of local taxes to regional variable income is a significant positive contribution to variable regional Infaq variable income is not notable positive. Tithe variable contribution towards regional variable pay is a significant positive contribution of the variable to variable Maslahah local tax is not significant positive contribution of geographical variables to variable Maslahah income is not a significant negative contribution to mutable Maslahah title variable is significantly positive, Infaq variable contribution towards Maslahah variable is significantly positive, regional changes in contributions by local income tax, donation, charity amounted to 55.2%, a shift Maslahah given by local tax contribution, Infaq, welfare, and regional income amounted to 53.6%. For the local contribution, Maslahah significant positive income to the charity and donation should be maximized not a tax.

scholarly journals The ARMR Classification System and the Modified Hoek-Brown Failure Criterion Compared to Directional Shear Strength Models for Anisotropic Rock Masses

2019 ◽  
Author(s):  
Neil Bar ◽  
Charalampos Saroglou
Keyword(s):  
Shear Strength ◽  
Rock Mass ◽  
Failure Criterion ◽  
Classification System ◽  
Failure Criteria ◽  
Rock Masses ◽  
Anisotropic Rock ◽  
Anisotropic Rock Mass ◽  
Degree Of Anisotropy ◽  
Strength Models

The anisotropic rock mass rating classification system, ARMR, has been developed in conjunction with the Modified Hoek-Brown failure to deal with varying shear strength with respect to the orientation and degree of anisotropy within an anisotropic rock mass. Conventionally, ubiquitous-joint or directional shear strength models have assumed a general rock mass strength, typically estimated using the Hoek-Brown failure criterion, and applied a directional weakness in a given orientation depending on the anisotropic nature of the rock mass. Shear strength of the directional weakness is typically estimated using the Barton-Bandis failure criterion, or on occasion, the Mohr-Coulomb failure criteria. Directional shear strength models such as these often formed the basis of continuum models for slopes and underground excavations in anisotropic rock masses. This paper compares ARMR and the Modified Hoek-Brown failure criterion to the conventional directional shear strength models using a case study from Western Australia.

scholarly journals A comparative study of the microtensile bond strength and microstructural differences between sclerotic and Normal dentine after surface pretreatment

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jinhua Wang ◽  
Weijian Song ◽  
Lei Zhu ◽  
Xin Wei
Keyword(s):  
Phosphoric Acid ◽  
Bond Strength ◽  
Sodium Hypochlorite ◽  
Resin Composite ◽  
The Other ◽  
Tensile Bond Strength ◽  
Strength Analysis ◽  
Class Iii ◽  
Surface Pretreatment ◽  
Dentine Surface

Abstract Background The resin bond strength of sclerotic dentine is significantly lower than that of the normal dentine, which paused a challenge for bonding procedures clinically. The aim of this study was to compare the effects of different surface pretreatments on the micro-tensile bond strength and microstructure between sclerotic dentine and normal dentine. Methods Eighty teeth that were collected, forty premolars with typical wedge-shaped defects visually graded as class III were assigned as the sclerotic dentine group (SD), the other forty normal premolars with artificial wedge-shaped defects were assigned as the normal dentine group (ND). Each group was randomly subdivided into eight subgroups according to the solution used: 35% phosphoric acid, 15% EDTA, 5% or 10% NaClO. Then the dentine surface was examined using a scanning electron microscope (SEM). The lesions were restored using self-etching adhesive and the subsequent resin composite. The teeth were sectioned into sticks for the micro-tensile bond strength analysis, and the data were analysed using the SPSS17.0 software package (α = 0.05). Results First, for the ND groups, after pretreatment using 35% phosphoric acid, and 35% phosphoric acid + 5% or 10% sodium hypochlorite, the bonding strengths of the normal dentine were higher than that of the other groups (P < 0.05). Second, for the SD groups, after pretreatment using 35% phosphoric acid, 15% EDTA, and 35% phosphoric acid + 5% or 10% sodium hypochlorite, the bonding strengths of the sclerotic dentine were higher than that of the other groups (P < 0.05). Third, the bond strengths of the sclerotic dentine were lower than that of the normal dentine without any pretreatment (P < 0.05). After pretreatment using 35% phosphoric acid + 5% or 10% sodium hypochlorite, the bonding strengths of the sclerotic dentine were higher than that of the normal dentine (P < 0.05). SEM observation showed that the appearances of dentine surface were changed after pretreatment using the above solutions, with the reduced smear layer, opened small groove and increased dentinal tubules. Conclusion Pretreatment of dentine using 35% phosphoric acid+ 5% or + 10% sodium hypochlorite changed the microstructure of the sclerotic dentine surface and subsequently increased the micro-tensile bond strength.

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