Study on founding of a residential–administrative complex in poor soil conditions in seismic prone region

This paper gives a brief presentation of the study on foundation of a residential business complex. The unfavourable geotechnical conditions of the site considered led to the need to improve the natural foundation soil. The most favourable and rational solution for providing safety and stability of structures was the combination of gravel and a sub-base. Computations were done as follows: analysis of the stress–strain state by using the parameters of the natural non-improved soil and analyses performed by using the parameters of the improved soil. The results from these analyses were used for analysis of the integral soil–structure system. Hence, complete information on the possibility for optimisation of the foundation structure was obtained.     

Natural environment suitability for human settlements in China based on GIS

With the degeneration of environment and acceleration of urbanization,human environment has attracted great attention worldwide.This paper sets up the Human Settlements Environment Index(HEI) model and evaluates the natural environment suitability for Human Settlements in China based on GIS technology.The results show that the HEI of China decreases from southeast to northwest in general,HEI is significantly correlated with population density at grid size and the correlation coefficient(r) between them reaches 0.93,which indicates that natural environment suitability for Human Settlements has a significant influence on population distribution.Most people in China mainly concentrate in areas with high natural environment suitability.The total suitable area is 430.47×104 km2,which accounts for nearly 45% of the total land area in China,while the proportion of people living in the area reaches 96.56%.With a population density of 18 people per square kilometer,the critical area is the transitional region for people to live in China.The critical area covers 225.11×104 km2 with a population of 41.12 million.The non-suitable area covers 304.42×104 km2 with a population of only 2.49 million.     

基于GIS的中国人居环境自然适宜性评价

With the degeneration of environment and acceleration of urbanization, human environment has attracted great attention worldwide. This paper sets up the Human Settle-ments Environment Index (HEI) model and evaluates the natural environment suitability for Human Settlements in China based on GIS technology. The results show that the HEI of China decreases from southeast to northwest in general, HEI is significantly correlated with population density at grid size and the correlation coefficient (r) between them reaches 0.93, which indicates that natural environment suitability for Human Settlements has a significant influence on population distribution. Most people in China mainly concentrate in areas with high natural environment suitability. The total suitable area is 430.47×104> km2, which ac-counts for nearly 45% of the total land area in China, while the proportion of people living in the area reaches 96.56%. With a population density of 18 people per square kilometer, the critical area is the transitional region for people to live in China. The critical area covers 225.11×104 km2 with a population of 41.12 million. The non-suitable area covers 304.42×104 km2 with a population of only 2.49 million.     

Failure analysis of the granite for a dam foundation

This paper presents the numerical and experimental investigation of a dam foundation. The site consists of granite and especially weathered granite. Numerical and analytical analyses have been conducted to evaluate suitability of the granite for a dam foundation. Mohr–Coulomb failure criterion has been used to calculate the compressive strength of the rock mass. Finite element implementation of Mohr–Coulomb criterion has been used for deformation and settlement analysis. Packer testing and in-situ estimation of rock mass deformability using the Goodman jack have been performed. The results of the evaluations show that very small normal and differential settlements can be expected in structural regions due to dam construction, and the compacted concrete dam can safely be constructed on either the competent granite or the weathered granite. However, the dam foundation on the weathered granite has high conductivity potential problems for the reservoir.     

Jacked model pile shafts in offshore calcareous soils

Abstract

This paper describes the results of laboratory tests carried out on model pile shafts in a variety of reconstituted calcareous sands and on silica sand. The factors influencing both the skin friction under static loading and the degradation of skin friction under cyclic loading have been investigated. The grading and crushability of the particles appears to have a significant influence on both, with less favourable performance being found for uniformly graded crushable particles. Relative density and overconsolidation ratio also have some influence.

Under cyclic loading, the amplitude of cyclic displacement and, more specifically, the cyclic slip displacement, influence the extent of cyclic degradation of skin friction.     

The impact of topography on social factors,a case study of Montenegro

Relationships between environmental and social factors have long been studied by geographers.Nowadays,GIS-aided statistical analysis provides new tools to explore these relationships.In order to detect the impact of topography on social factors,we selected the country of Montenegro as a case example due to its high topographic variability.We compared the spatial pattern of population,settlements and ethnic minorities to physical geographic factors,especially to topography,but lithology and land cover data were also taken into consideration.We found that certain factors are closely correlated,e.g.the settlement density linearly decreases with elevation,while the characteristic settlement area shows an exponential increase upwards.The population density is not related to absolute elevation,but it is in close correlation with height（i.e.elevation relative to the local minimum）.Population change and illiteracy are also topography-related social factors.On the contrary,the variable ethnic pattern of Montenegro is influenced by historical,political and economic effects rather than by environmental factors or topographic features.As a conclusion we state that in the scale of a country or a region,the environment can strongly impact some social factors.     

基于栅格的区域人居自然和人文环境质量综合评价——以京津冀地区为例

区域人居环境质量对于区域社会经济发展具有重要意义。本文以京津冀地区为例,基于人居自然要素指数（地形起伏度、气候指数、水文指数和植被指数）和人文要素指数（夜间灯光指数、空气质量指数和交通通达指数）构建了人居环境质量综合指数（HSCI）,分析了2010年其空间分异规律,并探讨了人口分布与人居环境质量的相关性。主要结论为：① 人居自然环境受距渤海距离和太行山脉的影响较为明显,呈现由东南向西北递减的空间分异规律。其中,紧邻渤海的天津市和沧州市最好,太行山西侧的张家口市和承德市最差。② 人居人文环境在城市地区明显优于非城市地区,并表现出与行政级别相一致的层级结构。同时由于南部空气质量较差,其人文环境整体劣于北部。其中,北京市人文环境最优,衡水市最差。③ 人居环境质量综合指数既表现出由东南向西北依次递减的规律,又表现出城市地区向非城市地区依次递减的圈层结构,以及高级别行政区优于低级别行政区的层级结构。其中,天津市和唐山市人居环境质量最优,张家口市和承德市最差。④ 京津冀地区人口并非在人居环境最好的地方分布最多,而是在人居环境中等的地方分布最多,二者呈正态分布规律。整体来看,人居环境质量综合指数大于0.6的土地约占35%,却聚集了约40%的人口,说明该区充分利用了高人居环境质量的土地,人口与人居环境质量分布较为协调。     

Non-linear soil–structure interaction in disconnected piled raft foundations

Disconnected piled raft foundations are characterised by no structural connection between the upper raft and the underlying piles, mostly playing the role of settlement-reducers. The resulting raft–pile gap is usually filled with a granular interlayer, through which the loads from the superstructure are transferred to the piles.In this paper, the complex interaction mechanisms involving the foundational components (raft, piles and soil) are numerically investigated by means of 3D finite elements analyses, accounting for soil non-linearity. The main features of the soil–structure interaction mechanisms under purely vertical external loads are explored over a realistic range of raft–soil gaps for different pile configurations, in which the number of piles – i.e. their spacing – is varied. Special attention is also devoted to the structural response of the piles in terms of axial and bending internal stress resultants. In particular, while disconnection beneficially affects the structural pile response, increasing the raft–pile gap tends to reduce the overall settlement/stiffness efficiencies.The numerical results being presented are in substantial agreement with the outcomes from literature small-scale experiments and suggest a number of relevant theoretical inferences.     

Rapid detection of new and expanding human settlements in the Limpopo province of South Africa using a spatio-temporal change detection method

Recent development has identified the benefits of using hyper-temporal satellite time series data for land cover change detection and classification in South Africa. In particular, the monitoring of human settlement expansion in the Limpopo province is of relevance as it is the one of the most pervasive forms of land-cover change in this province which covers an area of roughly 125 000 km². In this paper, a spatio-temporal autocorrelation change detection (STACD) method is developed to improve the performance of a pixel based temporal Autocorrelation change detection (TACD) method previously proposed. The objective is to apply the algorithm to large areas to detect the conversion of natural vegetation to settlement which is then validated by an operator using additional data (such as high resolution imagery). Importantly, as the objective of the method is to indicate areas of potential change to operators for further analysis, a low false alarm rate is required while achieving an acceptable probability of detection. Results indicate that detection accuracies of 70% of new settlement instances are achievable at a false alarm rate of less than 1% with the STACD method, an improvement of up to 17% compared to the original TACD formulation.     

Examining the influence of settlement morphology and separation zones policies on the availability of shallow coal resources in the United Kingdom

In 2013, demand for coal in the UK was 60 million tonnes. Of this, 12.7 million tonnes (21%) came from indigenous sources; the majority of which was from surface mining (8.6 million tonnes). Many planning applications for surface mining of coal and the coal extraction that follows, are often a source of conflict with the communities who live within shallow coalfield areas. Policies which enforce a gap, or ‘separation zone’, between communities and surface coal mining operations exist in Wales and Scotland, but do not exist in England. This paper examines the effect of applying separation zones on the availability of shallow coal resources within two study areas; one within the South Wales Coalfield, the other within the Midlands Coalfield (comprising the Yorkshire, Nottinghamshire and North Derbyshire Coalfield areas). Density profiles and a shape-index algorithm are used to compare and contrast settlement morphology (i.e. shape or footprint) and distribution to determine whether they have a bearing on the areal extent of any potential separation zone applied. The implications on the availability of shallow coal resources of applying different separation zone distances around settlements within these two areas are explored. Results reveal that although the settlement morphology is important in determining the area of the separation zone, and has greatest influence in the South Wales Coalfield, the area of coal resource sterilised by the application of separation zones is greatest in the Midlands Coalfield due to it having a higher proportion of urban development situated on the surface extent of the shallow coal resource.