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The purpose of this study was to investigate the likely causes of failure of some sections of road pavements in Ajaokuta, Northcentral Nigeria. This was achieved through a geotechnical assessment of subgrade soils in affected areas.

The methods entailed field and laboratory methods and statistical analysis. Subgrade soil samples were retrieved from a depth of 1,000 mm beneath the failed portions using a hang auger. The soils were analyzed for natural moisture content (NMC), Atterberg limit (liquid limit, plastic limit and linear shrinkage), grain size distribution, compaction and California bearing ratio (CBR), respectively.

The results of the geotechnical tests ranged from NMC (12.5%–19.4%), sand (84%–98%), fines (2%–16%), LL (16.0%–32.2%), PL (17%–27.5%), LS (2.7%–6.4%), PI (2.5%–18.4%), maximum dry density (1756 kg/m2–1961 kg/m2), optimum moisture content (13.2%–20.2%), unsoaked CBR (15.5%–30.5%) and soaked CBR (8%–22%), respectively. Pearson’s correlation coefficient performed on the variables showed that some parameters exhibited a strong positive correlation with r2 > 0.5.

Funding was the main limitation.

Comparing the results with Nigerian standards for road construction, and the AASHTO classification scheme, the subgrade soils are competent and possess excellent to good properties. The soils also exhibited very low plasticity, a high percentage of sand, high CBR and low NMC, which implies that it has the strength required for road pavement subgrades. The likely causes of the failures are, therefore, due to the use of poor construction materials, technical incompetence and poor compaction of sub-base materials, respectively.

Outlines the threat posed by landslides in Great Britain, and examines the ways in which potential problems can be identified and accommodated by developers and engineers in the light of changes in the Building Regulations for England and Wales which took effect on 1 June 1992. Explores the causes of landsliding, and suggests the appropriate investigations which should be instigated by the developer if suspecting instability. Discusses remedial measures and presents a study of landslide management with the example of Ventnor on the Isle of Wight. Mentions the Planning Policy Guidance issued by the Department of the Environment, which advises local authorities, landowners and developers on the role of planning controls as a landslide management tool.

A library is called a special library if it collects material on specific subjects or has special material or has special readers. The micro computer‐based dBASE II package is a viable tool to store, select, retrieve and manipulate numerical and alphabetical data. This capability can be rigourously exploited by a librarian to replace catalogues, indexes or any other records that are important from a management point of view. At the Centre of Studies in Resources Engineering (CSRE) of IIT, Bombay, India, a microcomputer‐based database has been developed to carry out the following functions for the library. 1) Storage and management of bibliographic data. 2) Selection and conditional retrieval of data. 3) Preparation of reports. This paper describes the concept, structure development, usage, advantages and limitations of the system. As the library is a service‐orientated organisation, then a computer will be a very effective tool in the hands of a librarian to perform library functions satisfactorily.

In the UK, responses to intense weather events regarding national and regional level perils include the support of a General Insurance policy at the address level as part of private residential and other insurance policies covering the key risks of flooding, subsidence and windstorm. In respect of the subsidence peril, dry summers can lead to many thousands of properties on shrinkable clay soils suffering differential downward movement as water is abstracted from the soil by vegetation. These events are forecast to increase in frequency and severity due to climate change, with costs for a dry event year of more than £500m to UK insurers. Assessing the character of these event years can inform government, local government, insurers and their agents as to the typical characteristics of an event year and its impacts. The purpose of this paper is to provide a comprehensive overview of the 2018 UK subsidence event year as it relates to trees and low rise buildings.

The research material is taken from claims that originated within the period commencing in the Summer of 2018, which in the UK was dry and with high levels of claim notification, and is from the private database of Property Risk Inspection Limited, one of the largest UK specialist subsidence claims handling businesses.

The data clearly illustrates the wide range of vegetative species causing or contributing to claims in the UK, their age ranges, sizes and conditions, management options and the range of land uses and statutory controls that exist in relation to title and other boundaries.

There have been various small-scale studies looking at individual cases of subsidence and the impacts of vegetation, but there have been no detailed investigations of large-scale claims-driven events such as the 2018 surge. The importance of this population-level investigation will only increase given the modelling for increased hot and dry summers over the coming decades.

This paper aims to investigate residents’ perceptions of risk towards owning and living in residential property in Christchurch subsequent to the 2010 and 2011 Canterbury earthquakes to identify how these perceptions impact on the price residents are willing to pay for affected property. Such market behaviour can motivate homeowners to adopt risk mitigation measures.

An online survey was developed and the Web link distributed to Canterbury residents via the media. This method of distribution was adopted, as a postal survey was not possible due to the number of homes that had been destroyed by the earthquakes and the highly transient nature of the community as a result.

The results indicate that with the recent earthquake experience, residents are demonstrating risk mitigation behaviours through an aversion to investing in properties affected by, or with a risk of, liquefaction. Specifically, the majority of respondents had strong reservations about buying Technical Category 3 property, and would be prepared to pay 20 per cent (or > 20 per cent) less for it, indicating some stigma towards affected property. Further, most respondents would now prefer the construction of their home to be of a type that fared better in the earthquakes: lightweight, single-storey, with a concrete slab foundation. These housing preferences will likely drive the market towards the adoption of risk mitigation measures in the retrofit of existing homes as well as in the design and construction of new homes.

Due to the number of homes that had been destroyed by the earthquakes and the highly transient nature of the community as a result, probability sampling was not possible. This, together with the low response rate, means that the respondents surveyed may not be representative of the Christchurch population.

The outcomes of this research will be of interest not only to homeowners wanting to know how their home’s value has been impacted by market perceptions towards earthquake and liquefaction damage, particularly in the worst-affected areas, but also the rating valuers tasked with assessing property values for rating purposes. Property developers and builders involved in the repair of existing homes and construction of new homes will also want to know current market preferences. Government bodies will find the results informative of how the media has, and can be used, to motivate market behaviour towards risk mitigation, particularly in regard to “material risk” (as described in Solberg et al., 2010), that is risk from a scientific and technical viewpoint of probability of future risk, and as related to what has become known about these risks in terms of building structure, height, age, soil type/land categories and flood zones. Further, the results provide a gauge of how the community perceived the handling of the recovery process, so that the weaknesses highlighted can be addressed, which will help restore community trust.

This study fills a research void on the impact of residents’ perceptions of risk towards home ownership in a city impacted by significant earthquakes and resulting liquefaction.

Canterbury, New Zealand, experienced two significant earthquakes in 2010 and 2011 with a devastating impact on both houses and land. Negative media attention to the potential financial risks of living near or on the new Technical Category 3 (TC3) land or on land in a flood zone has fuelled the perception of uncertainty over the negative property price impacts. This research aims to determine if residents’ perceptions of the risks associated with various types of land zones (e.g. TC1, TC2 and TC3) are reflected in property prices.

This research analyses sale price patterns and the relationship between sale prices and house characteristics before and after both earthquakes. A three-step approach was taken by applying: an average trend analysis, Geographic Information Systems’ (GIS) hotspot analysis to identify possible spatial differentiations between the before and after-effects of the earthquakes and hedonic modelling to quantify the effect of house characteristics on sale price while controlling for and comparing three land zones (TC1 to TC3).

The data suggest that average sale prices increased after both quakes in TC1 and TC2 in contrast to TC3 zones, while close to 8,000 structures were demolished in red zones from 2010-2013 (supply was reduced). The econometric modelling suggests that higher sale prices are achieved by: newer houses across all land zones and more recent sale agreements only in TC1 and TC2 zones. Other observations include the effect of certain exterior façade materials on sale prices on the overall data set and in the individual TC1 and TC3 zones. In conclusion, the results suggest that although caution might exist for the TC3 zone, the quality of the house can override the stigma attached to the TC3 zones.

A confounding factor in the research was that approximately 7,800 homes were rezoned red and/or demolished between 2010 and 2013 changing the supply and demand balance. Further, banks and other lenders updated their requirements for new lending on properties in the Canterbury region, requiring a number of reports from professionals such as structural engineers, geotechnical engineers and valuers before any new lending would be approved. Additionally, immediately after the September and February earthquakes, there was a 21-day stand-down period for earthquake-cover in Canterbury and without adequate insurance cover banks would not advance mortgage money, causing a short-term slowdown in the residential property market.

The outcomes of this research will be of interest to government agencies tasked with assessing compensation for affected property owners. For example, the Earthquake Commission (EQC) developed a Diminution of Value Methodology for Increased Flooding Vulnerability that formed the basis of a High Court declaratory judgment decision in December 2014 that cleared the way for the EQC to start settling properties with increased flooding vulnerability. The EQC methodology was informed by the results of similar studies to this one, from around the world. Homeowners and rating valuers will also be interested in the results to understand how house prices have been affected by market perceptions towards earthquake damage, particularly in the worst-affected areas.

This study fills a research void regarding the price impacts of residents’ perceptions of the risks associated with various types of land zones that reflect the expected future liquefaction performance of the land.

Has 1992 caught the popular imagination of the man in the Clapham commuter train? As Professor Joad would have said: ‘It all depends what you mean by the popular imagination’.

The study is carried out to analytically reconnoiter geotechnical index properties of subgrade soils as key variables that shape the cost profile of road infrastructure projects in a tropical geographic setting with starkly heterogenous ground conditions.

Using the Niger Delta region, as a point of reference, data on geotechnical index properties of subgrade soils at spatially dispersed locations for 61 completed highway projects are collated. Exploratory statistical tests were carried out to infer significant associations with final project costs before regression analysis. Regression analysis is principally deployed as an explanatory analytical tool, relevant to quantify the sensitivity of highway project costs to the individual and collective impact of geotechnical variables.

Several parameters of expansivity and compressibility exhibited significantly strong associations with the final costs recorded on the highway projects. The statistical analysis further established a cause-effect relationship, whereby small changes in the geotechnical properties of sub-grade soils at project locations, would result in disproportionately large changes in the cost of road construction.

The study findings provide insight into the sensitivity of road construction costs to geotechnical variables, which can serve as a useful input in financial risk analysis for development appraisal and the generation of location adjustment factors.

The study statistically demonstrates location-induced construction cost profiles, triggered in response to the spatial geotechnical variability and occurrence of problem subgrade soils in the humid tropics, which may be different from those traditionally established in studies of cold and temperate climate soils.

The “stigma” associated with remediated contaminated land is the blighting effect on property value caused by perceived risk and uncertainty. Uncertainties relate to negative intangible factors such as the inability to effect a total “cure”, the risk of failure of the remediation method, the risk of changes in legislation or remediation standards, the difficulty in obtaining finance, or simply a fear of the unknown. Post‐remediation “stigma” is the residual loss in value after all costs of remediation, including insurance and monitoring, have been allowed for. It equates to the difference in value between a remediated contaminated site and a comparable “clean” site with no history of contamination. The initial results from a study of the market sales data of post‐remediated vacant residential land along the Swan River, in Perth, Western Australia, from 1992‐1998 are summarized. The aim of this ongoing research is to estimate the amount of “stigma” arising from a site’s contamination history and measure the effect of this on residential property values of remediated property. The results show that while a site’s contamination history impacts negatively on property prices, the price decreases are offset by the positive influence on price from additional amenities provided in the case study neighbourhood.

This study aims to proffer a theoretical narrative explaining the poor financial performance of public highway agencies in Nigeria. This study critically spotlights seminal works in the literature offering theoretical narratives on the poor financial performance of public infrastructure projects, to discuss whether they adequately capture the relationship between psychological factors, project governance/leadership issues and knowledge/skill deficiencies related to the cost performance of infrastructure projects in the developing world. The evaluation reveals the predominant contextual exclusivity of these theoretical narratives to the developed world, which tend to under-represent developing countries, such as those on the African continent.

Using a case study research strategy, longitudinal documentary/archival data for 61 highway projects were analyzed. In total, 16 interviews were also conducted with highway officials from the three highway agencies responsible for the execution of the projects. A two-stage deductive-inductive thematic analysis of the collated data was carried out to identify barriers to the financial management of public highway projects, the result of which is cognitively mapped out.

The study showcases empirical insight on cost overruns experienced in Nigerian public projects, because of the trickle-down effect of human and organizational environment, as well as because of workers’ knowledge/skill deficiencies.

The developed theory is contextual to Nigeria, and there is scope for testing its generalisability to other developing nations.

The in-depth trajectory provided uncovers an intricate web of technical and psycho-social, organizational and institutional issues, which have not been identified and explained by previous theoretical narratives.