The extent of building and managing local contents in institutional repositories: a survey of tertiary institution libraries in Nigeria

Purpose The purpose of this study is to investigate the development of institutional repositories (IR) in tertiary institution libraries in Nigeria. Design/methodology/approach The study adopted a survey research method. Online questionnaire and IR site investigation methods were used to collect data from 25 university libraries in Nigeria. Findings The study revealed that only 25 (14.7%) universities out of the 170 universities in Nigeria have successfully developed IRs and registered their presence in OpenDOAR. Other tertiary institutions such as Polytechnics and Colleges of Education investigated in Nigeria are yet to develop IRs. Contents such as theses and dissertations, conference proceedings and journal articles ranked highest being the most popular contents in the various IRs. The results showed that the development of IR saves space in the library, increases readership, increases access to local contents, minimizes damage to the original material, facilitates the dissemination of scholarly research and assists in globalization of Nigerian research findings. The IRs site investigation revealed that only few IRs have clearly defined access policy, content policy, submission policy and digital preservation policy. The study identified challenges such as inadequate facilities, unstable internet connectivity, lack of fund, irregular power supply, challenge of collecting materials for the IR, lack of skilled ICT personnel, copyright issues and absence of IR policies. Practical implications The results from the study will provide important data and insight into the development of institutional repositories in tertiary institution libraries in Nigeria, and generate suggestions for University Librarians, College Librarians, Polytechnic Librarians, tertiary institutions management and policy makers for developing institutional repositories in Nigeria and other developing countries. Originality/value The study investigated IR development in tertiary institutions in Nigeria. The findings will inform other tertiary institutions in developing countries that the development of IR provides an opportunity for the visibility of local contents emanating from institutions and make them see the reason to embrace this laudable development.

Large Deformation Characteristics of Surrounding Rock and Support Technology of Shallow-Buried Soft Rock Roadway: A Case Study

The coal resources in the coal-rich area of western China are mostly located in the late diagenetic Cretaceous and Jurassic strata. In this paper, a study on the support of soft rock roadways was carried out in the background of the soft rock track roadway in the Jiebangou coal mine. The field investigation showed that the surrounding rocks of the roadway were weak, soft, and broken, and the surrounding rocks were cemented, with the roadway local deformation exceeding 1 m. The borehole television results showed that the surrounding rocks were mainly weak sandy mudstone and yellow mudstone. The average uniaxial compressive strength of the surrounding rock was 15.49 MPa. The roadway is a shallow buried soft rock roadway; site investigation revealed that the original U-shaped steel shed had an extremely low resistance to slip, the filling body behind the U-shaped steel shed fell off, the interaction between the U-shaped steel shed and the surrounding rock was poor, the U-shaped steel shed could not provide sufficient timely support resistance, and the bearing capacity of the U-shaped steel shed was far from consideration. The floor was not effectively supported. The floor had different degrees of the bottom drum, and frequent undercover caused new stress disturbances, which loosened the bottom corners of both rock types and made the shed legs move continuously inward, reducing the bearing capacity and actual support resistance of the bracket. Numerical calculations were performed to study the deformation characteristics of the surrounding rock of the tunnel and the yielding damage characteristics of the brace. The results showed that the current U-shack support strength was insufficient, the two sides were deformed by 950 mm, the bottom of the roadway bulged by 540 mm, and the surrounding rock was mainly shear damaged. The fall of the filler behind the shed caused damage to the U-shaped steel shed spire. Through site investigation results and numerical calculations, the deformation and damage characteristics of the soft rock roadway and its damage causes were analyzed, and the support technology system of ‘strengthening support for weak structural parts’ was proposed. This improved the mechanical properties of the weak structural support body, the stress state of the local surrounding rock, and the bearing capacity of the support structure, and effectively controlled the deformation, damage, and instability of the surrounding rock of the roadway, and deformation, damage, and destabilization of the roadway, thereby achieving overall stability for the surrounding rock of the roadway.

Investigation on the Effect of Probability Distribution on the Dynamic Response of Liquefiable Soils

This study investigated the effect of different probabilistic distributions (Lognormal, Gamma, and Beta) to characterize the spatial variability of shear modulus on the soil liquefiable response. The parameter sensitivity analysis included the coefficient of variation and scale of fluctuation of soil shear modulus. The results revealed that the distribution type had no significant influence on the liquefication zone. In particular, the estimation with Beta distribution is the worst scenario. It illuminated that the estimation with Beta distribution can provide a conservative design if site investigation is absent.

The capability of terrestrial laser scanning for monitoring the displacement of high-rise buildings

Recently, terrestrial laser scanner (TLS) has been increasingly used to monitor ofdisplacement of high-rise buildings. The main advantages of this technique are time-saving, higherpoint density, and higher accuracy in comparison with GPS and conventional methods. While TLS isordinary worldwide, there has been no study of the capability of TLS in monitoring the displacement ofhigh-rise buildings yet in Vietnam. The paper's goal is to build a procedure for displacement monitoringof high-rise buildings and assess the accuracy of TLS in this application. In the experiments, a scannedboard with a 60 cm x 60 cm mounted on a moveable monument system is scanned by Faro Focus3DX130. A monitoring procedure using TLS is proposed, including three main stages: site investigation,data acquisition and processing, and displacement determination by the Cloud-to-Cloud method (C2C).As a result, the displacement of the scanned object between epochs is computed. In order to evaluate theaccuracy, the estimated displacement using TLS is compared with the real displacement. The accuracydepends on scanning geometry, surface property, and point density conditions. Our results show that theaccuracy of the estimated displacement is within ± 2 mm for buildings lower than 50 m of height. Thus,TLS completely meets the accuracy requirements of monitoring displacement in the Vietnam Standardsof Engineering Surveying. With such outstanding performance, our workflow of using TLS could beapplied to monitor the displacement of high-rise buildings in the reality of geodetic production inVietnam.

Application of Electrical Resistivity Method to Site Characterisation for Construction Purposes at Institute of Agriculture Research and Training Moor Plantation Ibadan

This research was carried out within Institute of Agriculture Research and Training Moor Plantation Ibadan, Southwestern Nigeria, with the aim to ascertain suitability of the proposed site for building construction and usage. The geophysical investigation involved three electrical resistivity techniques; Vertical Electrical Sounding (VES) using the Schlumberger configuration, 2D ERT and 2-D electrical imaging using Dipole-dipole electrode configuration. Two traverses were established E–W direction cutting across geologic strike with a distance of 80 m and of varying inter-traverse spacing. Eight (8) VES stations were occupied covering the entire study area for layer stratification and geoelectric parameters. The results were qualitatively and quantitatively interpreted and are presented as sounding curves and geoelectric sections. The 2-D imaging gave information on the subsurface characteristic in the area with generally low apparent resistivity indicating low competence material. The results obtained from the VES delineate three geoelectric units which comprise of the topsoil, weathered layer and fresh basement. The results from the VES were used to determine the second order parameters. The entire results correlate well with one another showing that all the techniques used were complemented. This study has further justified the need for geophysical site investigation as pre-condition before any construction to avoid problems of differential settlement. In determining of foundation material, topography elevation, clay content and the depth of weak zones should be put into consideration, since the depth of the weak zone is appreciably high.

Assessment of Reclamation-induced Consolidation Settlement Considering Stratigraphic Uncertainty and Spatial Variability of Soil Properties

Consolidation analysis is a key task for reclamation design. Although consolidation is a long-term process, acceleration of consolidation is often preferred for speeding up the reclamations. Before proposing measures to accelerate consolidation and reclamation process, it is imperative to have an accurate prediction of consolidation settlement for fine-grained materials, which is greatly affected by spatial distribution of subsurface zones with different soil types (i.e., stratigraphic heterogeneities and uncertainty) and spatial variability of soil properties. In current practice, calculation of consolidation settlement often uses simplified stratigraphic boundaries and deterministic consolidation parameters without considering stratigraphic uncertainty or soil property spatial variability. The oversimplified practice might result in unconservative estimations of consolidation settlement and pose threats to safety and serviceability of constructed facilities on reclaimed lands. In this study, a stochastic framework is proposed for consolidation settlement assessment with explicit modeling of stratigraphic uncertainty and spatial variability of soil properties by machine learning and random field simulation from limited site investigation data. The proposed method effectively generates multiple realizations of geological cross-section and random field samples of geotechnical properties from limited measurements and offers valuable insights into spatial distribution of the estimated total primary consolidation settlement curves and angular distortion.

Assessment of landslide behaviour in colluvium deposit at Doi Chang, Thailand

The paper presents the case study of the recurrent slope movement in colluvium deposits at Doi Chang, Thailand. A thorough site investigation confirmed the slope movement rate corresponding to slow creep during dry season, while in the rainy season, its velocity remarkably increased. Despite frequent repair, the movement rate was sufficient to result in the recurrent damage of infrastructures like roads and buildings, causing economic loss and public concerns. Furthermore, surface mapping revealed that the hill's topography led to the concentration of flowing water in a particular area. This resulted in a high level of groundwater table, especially during the rainy season. The inclinometer installed in that area suggested an average movement rate of 20.5 mm/month in the wet season. In contrast, during the dry season, it was limited within 2 mm/month, indicating that the increase in the rate of slope movement in the colluvium deposit was primarily due to the rising groundwater table. Field and laboratory tests were conducted to determine the properties of the colluvium deposit. Landslide susceptibility assessment was performed using infinite slope model and later integrated with GIS to evaluate the factor of safety (FS) over a large area. The FS decreased below 1 when the groundwater level rose to 0.3 cm below the ground surface, and using GIS, based on infinite slope model, the potential risk zone were delineated.

Investigation of the Optimal Layout of the Roadway in Closely Spaced Ultra-Thick Coal Seams Mining with Remaining Coal Pillars

The reasonable layout of the roadway in closely spaced, ultra-thick coal seam mining is of great significance to mining safety. Based on the research background of repeated roof leaks in the process of repairing the return air roadway in working face No. 30503 in the Tashan Coal Mine, theoretical analysis, in situ engineering testing, and numerical simulation were jointly adopted to evaluate the stability of the return air roadway under two schemes of repairing the original return air roadway and excavating a new return air roadway. The results show that the vertical mining-induced fissure above the roadway will cause severe damage to the roadway due to the influence of working-face mining when restoration of the roadway excavation is adopted. When choosing to excavate a new return air roadway, the new return air roadway just staggers the vertical cracks located in the top slab of the original return air roadway, putting the roadway in a state of stress reduction, making the roadway itself more stable and conducive to support. Therefore, the new air return tunnel was selected to establish the working face. To ensure safety of the working face during the mining of the original return air roadway, the original return air roadway was filled with high water content materials. Site investigation data show that this material plays a cushioning role in the filling section of the original return air roadway during the mining of the 30503 working face, and the deformation of the new return air roadway during the filling section crossing the original return roadway is stable and well controlled.

Research on Campus Landscape Planning Strategy Based on the Ecological Health Effect

The water landscape in college and university is the research object in this article. Through on-site investigation, monitoring and computer simulation in campus, combined with qualitative and quantitative research methods, the advantages and disadvantages of the spatial layout of the water landscape in campus are compared. In addition, the surrounding building layout and greening layout are aslo separately studied in this article. The research results show the influence mechanism of the water landscape and its spatial layout on the ecological health effect, providing a reference experience and basis for the campus ecological landscape planning.