scholarly journals Study of Excavation Stability and Treatment Measures of the Side Slope of Anti-Dip Bedding Highway

2018 ◽  
Vol 206 ◽  
pp. 01003
Author(s):  
Qian Shen ◽  
Liu Liu ◽  
Jinxiu Yuan
Keyword(s):  
Rock Slope ◽  
Slip Surface ◽  
Side Slope ◽  
Whole Process ◽  
Engineering Measures ◽  
Treatment Measures ◽  
The Difference ◽  
The Stability ◽  
Numerical Simulation Technique ◽  
Important Significance

In order to improve the slope safety of the side slope of anti-dip bedding highway, this paper analyzes the stability of the excavation by using the finite difference numerical simulation technique. The development process of the disaster under the three excavation conditions and the whole process of the slip surface of the anti dip bedding rock slope are revealed; The method of determining the potential slip surface is introduced, that is to say, the slope is unstable and slip by reducing the material parameters of the slope, and then the position of the slip surface is judged by the difference of the displacement value. The research results have important significance for understanding the development mechanism of slope disaster and adopting corresponding engineering measures for different stages of slope.

Numerical Simulation on Failure Mechanism of Rock Slope Using RFPA

2011 ◽  
Vol 50-51 ◽  
pp. 568-572 ◽  
Author(s):  
Nu Wen Xu ◽  
Chu Nan Tang ◽  
Chun Sha ◽  
Ru Lin Zhang
Keyword(s):  
Rock Slope ◽  
Slip Surface ◽  
Process Analysis ◽  
Failure Process ◽  
Numerical Code ◽  
Natural State ◽  
Left Bank ◽  
Good Tool ◽  
Deep Rock ◽  
The Stability

This research applied a numerical code, RFPA2D (Realistic Failure Process Analysis) to evaluate the stability and investigate the failure mode of the high rock slope during excavations based on Strength Reduction Method (SRM). The corresponding shapes and positions of the potential slip surfaces are rationally simulated in different stages, and the related safety coefficients are obtained, which agrees well with the allowable minimum safety factors of the slope. The numerical results show that the safety coefficient drops from 1.25 at the natural state to 1.09 after excavation, and then increases to 1.35 after slope reinforcement. Moreover, the potential slip surface of the left bank moves into deep rock mass after taking support measures, which demonstrates the reinforcement is reasonable and efficient. The study shows that cracks and faults will cause crucial influences on the slope stability, and RFPA2D is a good tool to directly display the potential slip surface of the slope, which will offer valuable guidance for bolt support.

Stability Analysis of Unloading Slope by Interface Element Method

2012 ◽  
Vol 226-228 ◽  
pp. 1462-1466 ◽  
Author(s):  
Ying Xue Sun ◽  
Song Chen ◽  
Shuai Ran Cheng
Keyword(s):  
Rock Mass ◽  
Stability Analysis ◽  
Rock Slope ◽  
Interface Element ◽  
Rocky Slope ◽  
Natural Rock ◽  
Site Monitoring ◽  
The Difference ◽  
The Stability ◽  
Element Method

Mechanics behavior of unloading rock slope is essentially different from the natural rock slope . But, stability analysis of rocky slope during and after excavating still need these parameters and constitutional relation came from the natural rock slope, thus, the difference between the unloading rock mass and natural rock mass is neglected. The calculation result is quite different from the monitoring result. In order to analyze the stability of unloading rock slope properly, corresponding mechanics parameters including mechanics state, unloading degree and others should be determined and applied. In this paper, IEM - Sample Element Method and Interface Element Method expounded systematically and used to determine the corresponding mechanics parameters of a layered rock slope- Xishan slope of the Jiangyin Yangtze River Bridge. Then, IEM computer program based on Interface Element Method used to calculate the displacement of Xishan slope. Compare with displacement site-monitoring results, IEM is better than Finite Element Method.

Study on the Treatment Measures of Expansive Rock Slope

2012 ◽  
Vol 594-597 ◽  
pp. 92-95
Author(s):  
Er Ping Zhao ◽  
Xiao Bing Jia
Keyword(s):  
Rock Slope ◽  
Potential Harm ◽  
The North ◽  
Project Construction ◽  
Treatment Measures ◽  
Extreme Sensitivity ◽  
Project Characteristics ◽  
The Government ◽  
The Stability ◽  
Great Damage

Expansive rock is a special gneis with problems, spread widely in our country. Currently the government is carrying on constructions of infrastructure such as railways and transfer project of south water to the north. Such defective rock can disturb the construction process: due to its extreme sensitivity to temperature, humidity and stress field, swell rock has big potential harm to the project construction; a slight change in external factors could bring great damage to the project construction. Based on the analysis of the project characteristics, The thesis gives the treatment measures of expansive rock slope. The study is quite meaningful for the stability of the expansive rock slope.

scholarly journals Deformation Regulations and Failure Mechanism of High and Steep Layered Rock Slopes with Upper Steep and Lower Gentle Style Induced by Step-by-Step Excavations

2021 ◽  
Author(s):  
Zhiquan Yang ◽  
Xianglong Fan ◽  
Yi Yang ◽  
Kepeng Hou ◽  
Jun Du ◽  
...  
Keyword(s):  
Failure Mechanism ◽  
Slip Surface ◽  
Warning System ◽  
Rock Slopes ◽  
Layered Rock ◽  
Whole Process ◽  
Simulation Results ◽  
Two Phases ◽  
The Stability ◽  
Three Phases

Abstract High and steep layered rock slopes with upper steep and lower gentle style is a typical layered rock slope in Western region of China. Deformation regulations and failure mechanism of this kind of slope induced by step-by-step excavations were investigated in this study. By FLAC3D, excavation process is simulated according to actual situation (the first three phases) and planned excavation order (the last two phases). For the first three phases, through comparing simulation results and actual slope form, rationality of the model has been checked. For the last two phases, failure characteristics have been analyzed by simulation results. During the whole process of excavation, deformation can be summarized as "slip-bend-shear", and most dangerous slip surface of composite-style has been developed gradually into the slope. This research can provide theoretical support and guidance for the stability analysis, quantitative excavation design and pre-warning system of this type of slope in the process of western development in China.

scholarly journals Numerical Simulation of Dynamic Damage and Stability of a Bedding Rock Slope under Blasting Load

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Yekai Chen ◽  
Junhao Xu ◽  
Xiaohui Huo ◽  
Jinchang Wang
Keyword(s):  
Rock Slope ◽  
Highway Construction ◽  
Parameter Analysis ◽  
Vibration Velocity ◽  
Side Slope ◽  
Blasting Excavation ◽  
The Stability ◽  
The Right ◽  
Blasting Load ◽  
Bedding Rock Slope

Blasting excavation of a bedding rock slope is a common problem in highway construction in mountainous areas. Accurate simulation of damage area caused by blasting excavation is of great significance for the subsequent maintenance of slopes. Based on a highway construction project in Guangdong province of China, a tensile and compressive damage model was used to simulate the whole process of blasting excavation of a typical bedding rock slope. The analysis results show that damage first appears just around the blasting hole and then develops to the both sides and the bottom of the blasting hole, and finally a large range of damage appears in the lower part of the blasting hole, and the damage depth on the right-side slope is around 2 m, which is in consistent with the scene. Besides, damage also occurs in the middle of the bedding rock mass of the slope. At the same time, the history analysis of vibration velocity also indicates that tensile failure appears on the right-side slope under the blasting hole. Therefore, the stability of the slope can be assessed by analyzing the distribution of damage factors and the vibration velocity characteristics synthetically. In addition, parameter analysis was also carried out to optimize the blasting design by controlling the blasting load so as to obtain the ideal blasting excavation effect and ensure the stability of the slope under blasting load.

Eco-Engineering Measures for the Sandy Side-Slope Protection of Newly Regulated Rivers in Humid Region

2013 ◽  
Vol 831 ◽  
pp. 293-298
Author(s):  
Shou Hua Cai ◽  
Xing Wei Zhou
Keyword(s):  
Rainy Season ◽  
Vegetation Coverage ◽  
Native Vegetation ◽  
Annual Ryegrass ◽  
Regulated Rivers ◽  
Protection Measures ◽  
Side Slope ◽  
Humid Region ◽  
Engineering Measures ◽  
The Stability

In humid region, the natural vegetation coverage has not restored well on the side-slope of the newly-regulated rivers before the first rainy season comes. The plants which are planted on the side-slope have also not grown enough roots to stabilize the side-slope. As a result, on the sandy side-slopes serious erosion and collapse often occurs. Thus, in order to safely ride out the first rainy season after regulation, this paper presents some ecological slope-protection measures to utilize annual ryegrass and willow branches. The experiments show that planting annual ryegrass on the sandy side-slope can effectively prevent the side-slope from eroding and safely ride out the first rainy season after regulation. Meanwhile, the restoration of native vegetation wont be hindered. If the sandy side-slope is steeper, i.e., its stability is poorer, besides planting annual ryegrass, planting willow branches-root hedges in the side-slope is also necessary. Planting willow branch-root hedges can improve the survival rate of willows and the closure of plant hedges, and thus significantly enhance the stability of sandy side-slope.

Use of a Lyophilized Reference Plasma to Compare Coagulation Test Procedures

1975 ◽  
Vol 34 (02) ◽  
pp. 426-444 ◽  
Author(s):  
J Kahan ◽  
I Nohén
Keyword(s):  
Oral Anticoagulant Therapy ◽  
Repeated Measurements ◽  
Test Procedures ◽  
Coagulation Activity ◽  
Close Relationship ◽  
Measured Activity ◽  
Test Materials ◽  
The Difference ◽  
The Stability ◽  
The One

SummaryIn 4 collaborative trials, involving a varying number of hospital laboratories in the Stockholm area, the coagulation activity of different test materials was estimated with the one-stage prothrombin tests routinely used in the laboratories, viz. Normotest, Simplastin-A and Thrombotest. The test materials included different batches of a lyophilized reference plasma, deep-frozen specimens of diluted and undiluted normal plasmas, and fresh and deep-frozen specimens from patients on long-term oral anticoagulant therapy.Although a close relationship was found between different methods, Simplastin-A gave consistently lower values than Normotest, the difference being proportional to the estimated activity. The discrepancy was of about the same magnitude on all the test materials, and was probably due to a divergence between the manufacturers’ procedures used to set “normal percentage activity”, as well as to a varying ratio of measured activity to plasma concentration. The extent of discrepancy may vary with the batch-to-batch variation of thromboplastin reagents.The close agreement between results obtained on different test materials suggests that the investigated reference plasma could be used to calibrate the examined thromboplastin reagents, and to compare the degree of hypocoagulability estimated by the examined PIVKA-insensitive thromboplastin reagents.The assigned coagulation activity of different batches of the reference plasma agreed closely with experimentally obtained values. The stability of supplied batches was satisfactory as judged from the reproducibility of repeated measurements. The variability of test procedures was approximately the same on different test materials.

A Problem of Long - Term Digital Preservation: Difference in Humanities and Natural Sciences

2014 ◽  
Vol 3 ◽  
pp. 183-195
Author(s):  
Elena Macevičiūtė
Keyword(s):  
Social Sciences ◽  
Digital Preservation ◽  
Dynamic Activity ◽  
Private Companies ◽  
Time Line ◽  
Digital Documents ◽  
Whole Process ◽  
The Difference ◽  
Technological Science

The article deals with the requirements and needs for long-term digital preservation in different areas of scholarly work. The concept of long-term digital preservation is introduced by comparing it to digitization and archiving concepts and defined with the emphasis on dynamic activity within a certain time line. The structure of digital preservation is presented with regard to the elements of the activity as understood in Activity Theory. The life-cycle of digitization processes forms the basis of the main processing of preserved data in preservation archival system.The author draws on the differences between humanities and social sciences on one hand and natural and technological science on the other. The empirical data characterizing the needs for digital preservation within different areas of scholarship are presented and show the difference in approaches to long-term digital preservation, as well as differences in selecting the items and implementing the projects of digital preservation. Institutions and organizations can also develop different understanding of preservation requirements for digital documents and other objects.The final part of the paper is devoted to some general problems pertaining to the longterm digital preservation with the emphasis of the responsibility for the whole process of safe-guarding the cultural and scholarly heritage for the re-use of the posterior generations. It is suggested that the longevity of the libraries in comparison with much shorter life-span of private companies strengthens the claim of memory institutions to playing the central role in the long-term digital preservation.

In the stability of paints and varnishes for protective and decorative wood finish

2016 ◽  
Author(s):  
Ю.И. Цой
Keyword(s):  
Organic Solvents ◽  
Evaluation Criteria ◽  
Ternary Systems ◽  
Solubility Parameters ◽  
Formaldehyde Resin ◽  
Film Forming ◽  
The Difference ◽  
Molecular Forces ◽  
The Stability ◽  
Thermodynamic Interaction

Задача получения однородного состава ЛКМ сводится к правильному выбору пленкообразователей и соответствующих растворителей и, в случае необходимости, разбавителей и добавок. На основе положений теории растворимости была проведена оценка совместимости компонентов и стабильности таких систем. Критериями оценки были приняты параметры растворимости и термодинамического взаимодействия. Исследовали совместимость алкидных лаков с аминоформальдегидными смолами в бутаноле, и результаты этих исследований представлены в треугольной фазовой диаграмме. Для оценки совместимости смол по результатам расчета параметров термодинамического взаимодействия были построены спинодали для тройных систем. Как показывает анализ результатов проведенных исследований, даже при большой разности ?? = |?12 – ?13| = 0,2 наблюдается небольшая область несовместимости. С уменьшением разности ?? область несовместимости сужается. При ?23 > ?с область несовместимости расширяется как для ? = 0,2, так и для ?? = 0,1 и ?? = 0. Таким образом, для таких систем на совместимость компонентов, в первую очередь, влияет их взаимодействие между собой – чем оно больше, тем лучше они совместимы. Проведенные исследования показали, что парциальные параметры растворимости, учитывающие природу когезионных сил, более объективно характеризуют растворимость пленкообразующих смол в органических растворителях, чем их общий параметр растворимости. Растворимость пленкообразующих алкидных и этерифицированных аминоформальдегидных смол в органических растворителях обусловлена термодинамическим взаимодействием молекулярных сил различной природы. Стабильность смеси алкидной и этерифицированной аминоформальдегидной смолы в бутаноле обусловлена в большей степени термодинамическим взаимодействием молекулярных сил; при этом степень бутанолизации меламиноформальдегидной смолы оказывает наибольшее влияние на стабильность cистемы. Проведенные исследования по стабильности лакокрасочных смесей из различных пленкообразующих смол на основе рассмотренных критериев оценки могут быть использованы для совершенствования технологии защитно-декоративной отделки древесины. The problem of obtaining a homogeneous composition of the coatings is reduced to the proper selection of film-forming agents, and diluent and, if appropriate, diluents and additives. On the basis of the theory of solubility, we have carried out the assessment of the compatibility of the components and stability of such systems. The evaluation criteria were adopted the parameters of the solubility and thermodynamic interaction. Researched the compatibility with alkyd varnishes aminoformaldehyde resin in butanol, and the results of these studies are presented in the triangular phase diagram. To evaluate the compatibility of the resins according to the results of calculation of thermodynamic parameters of interaction were built spinodal for ternary systems. As the analysis of the results of the studies, even when the difference ??|?12 – ?13| = 0,2 there is a small area of incompatibility. With the decrease of the difference ? ? region incompatibility narrows. When ?23> ?с region incompatibility extends to ?? = 0,2, and for ?? = 0.1 and ?? = 0. Thus, for such systems, compatibility of components, primarily, affects their interaction with each other – the further away it is, the better they are compatible. Studies have shown that the partial solubility parameters, which take into account the nature of cohesive forces, more objectively characterize the solubility of film-forming resins in organic solvents than their total solubility parameter. The solubility and film-forming aminoformaldehyde esterified alkyd resins in organic solvents due to thermodynamic interaction of molecular forces of different nature. Тhe stability of the mixture and aminoformaldehyde esterified alkyd resin in butanol is generated largely by thermodynamic forces of molecular interaction; the degree of butanolate melamine-formaldehyde resin has the greatest effect on the stability of the system. Conducted research on the stability of the paint mixtures of various film-forming resins on the basis of the evaluation criteria can be used to improve the technology of protective and decorative wood finish.

Stability and mutual impact of perception of parental pressure and infants' social support – A study based on the difference between employment status and household income

2021 ◽  
pp. 002072092199705
Author(s):  
Yong Wang
Keyword(s):  
Household Income ◽  
Employment Status ◽  
Working Mothers ◽  
Social Research ◽  
Research Report ◽  
Parental Pressure ◽  
Income Levels ◽  
Significant Difference ◽  
The Difference ◽  
The Stability

The purpose of this study is to explore the stability and interaction between parental pressure and social research report, as well as the role of employment status and family income levels in this process. This study used a special study on Korean children (PSKC) 2–4 waves. Use t-test, correlation and autoregressive cross-delay modeling to analyze the data. The main findings of this study are: First, over time, parental pressure and mother’s social research report are consistent. Secondly, the pressure of motherhood and childcare has an obvious lagging effect on upbringing, and vice versa. Third, there is no significant difference between working mothers and non-working mothers in terms of the stability of working parents' pressure, social research report and social research report for children's pressure channels. However, parental pressure can only predict the social research report of working mothers. Fourth, there is no significant difference between the stability and interaction of these two structures in household income levels. In short, the results show that, over time, parental pressure is consistent with mother’s social research report. The results also show that there is a significant cross-lag effect between the mothers’ perceptions of mutual pressure analysis. In the process from parental pressure to social research report, I found the difference between working and non-working mothers. The advantage of this study is that the expected longitudinal design was adopted during infancy and the priority between the two structures can be considered. The results of this study can be used as a source of intervention plans to help parents withstand severe parenting pressure and lack of social research report.

Sign in / Sign up

Export Citation Format

Share Document