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Article
Publication date: 17 April 2018

Yongxing Guo, Jianjun Fu, Longqi Li and Li Xiong

Centrifugal model tests can accelerate the characterization of landslides and demonstrate the form of slope failure, which is an important measure to research its…

Abstract

Purpose

Centrifugal model tests can accelerate the characterization of landslides and demonstrate the form of slope failure, which is an important measure to research its instability mechanisms. Simply observing the slope landslide before and after a centrifugal model test cannot reveal the processes involved in real-time deformation. Electromagnetic sensors have severed as an existing method for real-time measurement, however, this approach has significant challenges, including poor signal quality, interference, and complex implementation and wiring schemes. This paper aims to overcome the shortcomings of the existing measurement methods.

Design/methodology/approach

This work uses the advantages of fiber Bragg grating (FBG) sensors with their small form-factor and potential for series multiplexing in a single fiber to demonstrate a monitoring strategy for model centrifugal tests. A slope surface deformation displacement sensor, FBG anchor sensor and FBG anti-slide piling sensor have been designed. These sensors are installed in the slope models, while centrifugal acceleration tests under 100 g are carried out.

Findings

FBG sensors obtain three types of deformation information, demonstrating the feasibility and validity of this measurement strategy.

Originality/value

The experimental results provide important details about instability mechanisms of a slope, which has great significance in research on slope model monitoring techniques and slope stability.

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Article
Publication date: 12 October 2010

Alireza Ahangar‐Asr, Asaad Faramarzi and Akbar A. Javadi

Analysis of stability of slopes has been the subject of many research works in the past decades. Prediction of stability of slopes is of great importance in many civil…

Abstract

Purpose

Analysis of stability of slopes has been the subject of many research works in the past decades. Prediction of stability of slopes is of great importance in many civil engineering structures including earth dams, retaining walls and trenches. There are several parameters that contribute to the stability of slopes. This paper aims to present a new approach, based on evolutionary polynomial regression (EPR), for analysis of stability of soil and rock slopes.

Design/methodology/approach

EPR is a data‐driven method based on evolutionary computing, aimed to search for polynomial structures representing a system. In this technique, a combination of the genetic algorithm and the least square method is used to find feasible structures and the appropriate constants for those structures.

Findings

EPR models are developed and validated using results from sets of field data on the stability status of soil and rock slopes. The developed models are used to predict the factor of safety of slopes against failure for conditions not used in the model building process. The results show that the proposed approach is very effective and robust in modelling the behaviour of slopes and provides a unified approach to analysis of slope stability problems. It is also shown that the models can predict various aspects of behaviour of slopes correctly.

Originality/value

In this paper a new evolutionary data mining approach is presented for the analysis of stability of soil and rock slopes. The new approach overcomes the shortcomings of the traditional and artificial neural network‐based methods presented in the literature for the analysis of slopes. EPR provides a viable tool to find a structured representation of the system, which allows the user to gain additional information on how the system performs.

Details

Engineering Computations, vol. 27 no. 7
Type: Research Article
ISSN: 0264-4401

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Book part
Publication date: 29 August 2005

Kai S. Cortina, Hans Anand Pant and Joanne Smith-Darden

Over the last decade, latent growth modeling (LGM) utilizing hierarchical linear models or structural equation models has become a widely applied approach in the analysis…

Abstract

Over the last decade, latent growth modeling (LGM) utilizing hierarchical linear models or structural equation models has become a widely applied approach in the analysis of change. By analyzing two or more variables simultaneously, the current method provides a straightforward generalization of this idea. From a theory of change perspective, this chapter demonstrates ways to prescreen the covariance matrix in repeated measurement, which allows for the identification of major trends in the data prior to running the multivariate LGM. A three-step approach is suggested and explained using an empirical study published in the Journal of Applied Psychology.

Details

Multi-Level Issues in Strategy and Methods
Type: Book
ISBN: 978-1-84950-330-3

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Article
Publication date: 25 January 2021

Zhen Wang, Huanling Wang, Weiya Xu and W.C. Xie

This paper aims to analyze the influence of rotated anisotropy on the stability of slope, the random finite element method is used in this study.

Abstract

Purpose

This paper aims to analyze the influence of rotated anisotropy on the stability of slope, the random finite element method is used in this study.

Design/methodology/approach

The random field is generated by the discrete cosine transform (DCT) method, which can generate random field with different rotated angles conveniently.

Findings

Two idealized slopes are analyzed; it is observed that the rotated angle significantly affects the slope failure risk. The two examples support the conclusion that when the orientation of the layers is nearly perpendicular to the slip surface, the slope is in a relative stable condition. The results of heterogeneous slope with two clay layers demonstrate that the rotated angle of lower layer mainly controls the failure mechanism of the slope, and the rotated angle of upper layer exhibits a significant influence on the probability of slope failure.

Originality/value

The method for rotated anisotropy random field generation based on the DCT has a simple expression with few parameters and is convenient for implementation and practical application. The proposed method and the results obtained are useful for analyzing the stability of the heterogeneous slopes in engineering projects.

Details

Engineering Computations, vol. 38 no. 7
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 10 January 2020

Hawraa Alateya and Alireza Ahangar Asr

This study is an attempt to estimate the influence of the presence of cavities on the stability of slopes in earth dams under rapid drawdown conditions. The purpose of…

Abstract

Purpose

This study is an attempt to estimate the influence of the presence of cavities on the stability of slopes in earth dams under rapid drawdown conditions. The purpose of this paper is to study the influence of different factors, such as the diameter and location of cavities, in addition to their existence effects.

Design/methodology/approach

A series of finite element simulation models were developed using PLAXIS 2D finite element software to analyse the stability of slopes in earth dams while considering various effects from cavities in the subsoil under rapid drawdown conditions.

Findings

The results indicated that the presence of cavities and an increase in the diameter of cavities decreased the stability of the upstream face dramatically for all examined locations in a horizontal direction; however, this effect was less on the downstream side. The results also showed that variations in the location of cavities in the horizontal direction have a greater effect on the stability than those in the vertical direction. The results revealed that increasing shear strength parameters of embankment does not reduce the influence of cavities on stability when those cavities are in critical locations.

Originality/value

A numerical model has been developed to simulate the effects of cavities on the stability of slopes in water-retaining structures/earth dams. The stability of earth dam slopes on upstream and downstream sides under rapid drawdown conditions considering various cavity effects, including their existence, diameter and location, were numerically analysed.

Details

Engineering Computations, vol. 37 no. 4
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 19 June 2009

Ashish Kumar Singh

The purpose of this paper is to attempt to generate a better, systematic and scientific understanding of the basic reasons behind slope instability to help in developing…

Abstract

Purpose

The purpose of this paper is to attempt to generate a better, systematic and scientific understanding of the basic reasons behind slope instability to help in developing the basic principles of landslide hazard zonation, monitoring and forecasting of landslide hazards for better and more effective landslide hazard mitigation and management.

Design/methodology/approach

The study is based on extensive field observations and intensive reviews of literature from secondary sources.

Findings

Mass movements especially landslides as they are known to common man are a recurring natural phenomenon and are an integral part of any geological/geomorphological circle of landform development through sequential development of slopes in any elevated region and especially in young fold mountain chains.

Practical implications

The paper presents a valuable insight into the basic reasons behind a landslide to spread awareness, to educate and sensitize people towards better and effective landslide hazard mitigation and thereby ensure people's participation in disaster management. It also aims to initiate and encourage research in the field of landslide management.

Originality/value

Landslides occur frequently and without any appreciable warning as such causing havoc and often insurmountable damage to life and property but despite their uncertainty, their causative factors and indicators of slope instability are very well known to an extent that the magnitude of these events, susceptible areas, the timing of such events and their potential impact can be studied, analyzed and evaluated on the basis of past occurrences and existing knowledge to mitigate their impact. The real value of the present study is to minimize losses due to landslides through better knowledge and enhanced levels of understanding of the phenomenon and its management by simply avoiding those particular reasons that could lead to slope instability problems.

Details

Disaster Prevention and Management: An International Journal, vol. 18 no. 3
Type: Research Article
ISSN: 0965-3562

Keywords

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Article
Publication date: 22 June 2010

Ashish Kumar Singh

Mass movements, especially landslides, are a recurring natural phenomenon and are an integral part of any geological/geomorphological cycle of landform development through…

Abstract

Purpose

Mass movements, especially landslides, are a recurring natural phenomenon and are an integral part of any geological/geomorphological cycle of landform development through sequential development of slopes in any elevated region and especially in young fold mountain chains. The purpose of this paper is to develop and evolve cheap, affordable, environment friendly and ecologically sustainable techniques of landslide disaster management and prevention.

Design/methodology/approach

The study is based on extensive research and field observations of various landslide management projects over the past decade and includes an intensive review of literature from secondary sources.

Findings

Landslide management aims to facilitate, and as far as possible accelerate the ongoing process of development on a sustainable basis, by preventing (reducing) the loss of lives and property by applying modern science and technology and taking appropriate measures and safety precautions at the right place at the right time. Landslide management, even in the most developed countries, has suffered from lack of adequate financial resources. Bioengineering offers an environment friendly and highly cost and time effective solution to the slope instability problems in mountainous and hilly areas.

Practical implications

The paper aims to initiate and encourage research in the field of landslide management with the viewpoint that green technology is a clean and affordable technology (both financially and ecologically).

Originality/value

The paper shows that bioengineering is highly cost effective and has very high cost‐benefit ratio. Bioengineering techniques when used in combination with civil and social engineering measures reduce the overall cost of landslide mitigation considerably which is the key factor for developing nations. Bioengineering has a very high success rate and is much more sustainable, eco‐friendly and affordable than other available options.

Details

Disaster Prevention and Management: An International Journal, vol. 19 no. 3
Type: Research Article
ISSN: 0965-3562

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Article
Publication date: 1 March 1998

Ngai Weng Chan

Malaysia is an ex‐colonial, newly‐industrialising country, with a sustained high economic growth rate averaging eight per cent GDP per annum over the past ten years…

Abstract

Malaysia is an ex‐colonial, newly‐industrialising country, with a sustained high economic growth rate averaging eight per cent GDP per annum over the past ten years. Within such a rapidly booming economy, the pace of social, economic and political change is fast, as is the pace of technological change. Other things being equal, these are the changes in which environmental hazards can be magnified. As a result of rapid economic development, physical systems are disturbed and changed. For example, the modification of the hydrological cycle due to deforestation, urbanisation, development of hill slopes and other human land use have given rise to increased risks of landslides. In recent years, the collapse of a block of luxury condominiums in Kuala Lumpur, the Genting Highland and Pos Dipang landslide tragedies as well as other landslide disasters have caused substantial loss of life and damage to property and infrastructure. Combined with intensive development of hill slopes and hill land for housing, recreation, tourism, agriculture, highway and dam construction, and other human induced land use changes, the exposure and vulnerability of human populations to landslide hazards have also increased. Other reasons, largely structural, such as persistent poverty, low residential and occupational mobility, and landlessness, manifested in illegal squatting and farming on hill slopes and foothills have also contributed to increased vulnerability of large communities to landslide hazards in many parts of the country. As Malaysia pushes ahead to meet its target of becoming a fully industrialised country by the year 2020, further environmental degradation is expected to occur. Notwithstanding other aspects of environmental degradation, the occurrence of landslide hazards is expected to become a common feature of Malaysian life.

Details

Disaster Prevention and Management: An International Journal, vol. 7 no. 1
Type: Research Article
ISSN: 0965-3562

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Article
Publication date: 1 April 2006

Eric J. Levin and Robert E. Wright

The purpose of the analysis is to estimate price elasticities of demand for individual FTSE‐100 stocks between 1 August 1994 and 31 July 1995.

Abstract

Purpose

The purpose of the analysis is to estimate price elasticities of demand for individual FTSE‐100 stocks between 1 August 1994 and 31 July 1995.

Design/methodology/approach

This paper measures excess demand in order to measure the slope of the demand curve for individual stocks. An econometric approach is adopted that models the slope of the excess demand curve within an econometric framework using signed market maker transactions data between 1 August 1994 and 31 July 1995.

Findings

The findings confirm that the demand curves for individual stocks do slope downwards. For example, the mean estimated percentage fall in stock price caused by a new share issue that is 1 per cent of the existing number of outstanding shares is −5.6.

Practical implications

Downward sloping demand curves pose difficulties for theories in finance that rely on the law of one price and price‐takers in competitive markets. For example, the dividend policy and capital structure irrelevance theorems of corporate finance, and the efficient markets hypothesis assumption that the price of a stock is determined only by information about future cash flows and the discount rate are not consistent with a downward sloping demand curve.

Originality/value

The slope of the demand curve is estimated using an econometric model and market makers' transactions data for specific stocks. This approach identifies observable unexpected shifts in the demand for a stock as unexpected changes in market makers' inventories. This approach is superior to event studies because it provides multiple observations that enable the slope of the demand curve to be quantified with sufficient confidence to calculate the price elasticity of demand for the stock.

Details

Studies in Economics and Finance, vol. 23 no. 1
Type: Research Article
ISSN: 1086-7376

Keywords

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Article
Publication date: 28 August 2009

Ravindra K. Pande, Dhanjita Burman and Ravinder Singh

The purpose of this paper is to evaluate landslide hazard problems in Hanuman Chatti area of Uttarakhand, India. Every year NH 58 experiences landslide activities, which…

Abstract

Purpose

The purpose of this paper is to evaluate landslide hazard problems in Hanuman Chatti area of Uttarakhand, India. Every year NH 58 experiences landslide activities, which disrupts the tourist traffic to Badrinath shrine and higher Himalaya.

Design/methodology/approach

An urgent need is being felt to have a comprehensive landslide hazard evaluation factor (LHEF). The major causative factors that influence the slope stability are lithology, structure, soil depth, soil texture, geomorphology, slope morphology, slope dip, slope aspect, slope magnitude, weathering, land use and land cover and anthropogenic activities. The present analysis is based on the rating scheme in which numerical ratings for different categories are determined on the basis of their estimated significance in causing instability.

Findings

In the study area, nine old landslides (0.238 sq.km) and five new landslides (0.086 sq.km) are recorded. On the basis of the various causative factors the study area is classified into five landslide hazard classes.

Research limitations/implications

The analysis is based on the experience gained for the last seven years (1999‐2007). The period is short for developing any hypothesis but sufficient care has been taken to consider vital factors.

Practical implications

With the help of LHEF appropriate landslide hazard management tools can be adopted. Once a LHEF rating scheme in which numerical ratings for different categories are determined on the basis of their estimated significance in causing instability, is standardized it can be applied to the entire Himalayan region, which is very prone to landslide hazard.

Originality/value

Although the paper is an attempt to evaluate the efficacy of landslide hazard zonation techniques developed by various agencies in the past, some modification as per the requirement has been made in various stages of investigation.

Details

Disaster Prevention and Management: An International Journal, vol. 18 no. 4
Type: Research Article
ISSN: 0965-3562

Keywords

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