Why is the future ready for environmental geotechnics?

The perception of geotechnical problems has, in recent years, been challenged by requirements for balance between traditional engineering and environment-friendly, sustainable solutions. Modern geotechnical engineers have to develop knowledge on the environment surrounding their solutions and thrive within the new discipline of environmental geotechnics. The general trends in the discipline are used as a background to personal experience to establish the place of a generic environmental geotechnics framework within the sustainable development area. Recent developments and potential future trends in areas that could be considered as part of environmental geotechnics are briefly outlined together with the need for training and education. </jats:p

Themed issue on selected papers SEG2015: part II

This themed issue of Geomechanics for Energy and the Environment ‘SEG-2015-Part II’, presents papers selected from extended abstracts submitted to the Symposium on Energy Geotechnics (SEG-2015) held in the Civil Engineering School of the Universitat Politècnica de Catalunya in Barcelona, Spain, between June 2nd and 4th, 2015. This symposium SEG-2015 was the first event organized by the Technical Committee TC308 of the International Society for Soil Mechanics and Geotechnical Engineering, which will have continuity in the next symposium SEG-2018 to be held in the École Polytechnique Fédérale de Lausanne (Lausanne, Switzerland). The first issue ‘SEG-2015-Part I’ appeared just before the 1st International Conference on Energy Geotechnics (ICEG-2016), which was held in Kiel (Germany) at the end of August 2016. The second volume ‘SEG-2015-Part II’ on December 2016 will thus close a first cycle of successful conferences and publications along this initial stage of TC308.Peer ReviewedPostprint (author's final draft

On preconditioning strategies for geotechnics

Iterative solvers are of increasing interest in geomechanics with the move towards 3D finite element modelling. Potentially, these methods can lead to reduced computational complexity as, unlike direct methods, they do not require the full system matrix to be assembled. In general, however, iterative solvers have not been widely adopted in geomechanics due to problems with convergence. This paper reviews the background to iterative methods for elastic and elasto-plastic material models. In some cases, existing numerical methods can be taken from research in the mathematics community. For other systems, further work is needed. The paper provides demonstrations of the capabilities of some strategies

Seismic site effects in a deep alluvial basin: numerical analysis by the boundary element method

The main purpose of the paper is the numerical analysis of seismic site effects in Caracas (Venezuela). The analysis is performed considering the boundary element method in the frequency domain. A numerical model including a part of the local topography is considered, it involves a deep alluvial deposit on an elastic bedrock. The amplification of seismic motion (SH-waves, weak motion) is analyzed in terms of level, occurring frequency and location. In this specific site of Caracas, the amplification factor is found to reach a maximum value of 25. Site effects occur in the thickest part of the basin for low frequencies (below 1.0 Hz) and in two intermediate thinner areas for frequencies above 1.0 Hz. The influence of both incidence and shear wave velocities is also investigated. A comparison with microtremor recordings is presented afterwards. The results of both numerical and experimental approaches are in good agreement in terms of fundamental frequencies in the deepest part of the basin. The boundary element method appears to be a reliable and efficient approach for the analysis of seismic site effects

Assessment of static and dynamic stresses horse-shoe tunnel with connecting gallery using finite element method: (as a case study)

This paper illustrates the use of MIDAS GTS NX to investigate the tunnel’s simulation in order to highlight the effect of static and dynamic load on the behaviour of tunnel to compare this response expressed in terms of displacement and stresses acting on the tunnel and ground. Main tunnel is located in the ground having uniform property throughout its extent, connecting gallery is located perpendicular to the main tunnel, the shotcrete and rock bolts for each tunnel will be installed

Effect of moisture on mechanical behavior of granular material in initial laboratory and mechanical tests

In this article authors present results of initial laboratory tests and further numerical analyses using finite element method (FEM) and back - calculation method. Laboratory tests are based on trial loadings of granular material in different moisture conditions. Numerical analyses were obtained in FEM software using Coulomb - Mohr model of tested material. Presented results are the part of wider research program in which the main aim is to evaluate the influence of variable moisture content of granular materials used in road pavement structures on their fatigue life and in Life Cycle Assessment (LCA)

Buku Teks: Reka Cipta Tingkatan 5

Buku teks Reka Cipta Tingkatan 5 ini merupakan buku teks yang dihasilkan berdasarkan keperluan Kurikulum Standard Sekolah Menengah (KSSM) Mata Pelajaran Elektif Ikhtisas (MPEI) dan Dokumen Standard Kurikulum dan Pentaksiran (DSKP) Reka Cipta Tingkatan 5 yang disediakan oleh Bahagian Pembangunan Kurikulum (BPK), Kementerian Pendidikan Malaysia. Buku ini mengandungi lapan bab yang ditulis berdasarkan dua kluster. Bab satu hingga empat ditulis berdasarkan Teknologi Pembuatan. Dalam kluster ini, murid akan diberi pendedahan dari aspek pengetahuan, kemahiran dan nilai bagi bidang teknologi di samping dilatih dalam pengujian dan pengukuran kefungsian produk yang dihasilkan. Bab lima hingga lapan pula ditulis berdasarkan Strategi Pemasaran. Dalam strategi pemasaran, murid didedahkan mengenai produk, harga, promosi, tempat dan harta intelek kepada produk, strategi pemasaran serta proses komunikasi dan dokumentasi yang berkesan. Buku ini turut menerapkan pelbagai pendekatan pembelajaran yang sesuai dengan keperluan semasa seperti Pembelajaran Kendiri, Pembelajaran Kolaboratif, Pembelajaran Berasaskan Projek, Inkuiri, Penyelesaian Masalah, Pembelajaran Masteri, Konstruktivisme, Pembelajaran Penerokaan dan Pendekatan STEM (Science, Technology, Engineering and Mathematics). Sehubungan dengan itu, buku ini diharap dapat mewujudkan suatu dimensi pengajaran dan pembelajaran Reka Cipta yang lebih berkesan. Bagi tujuan menarik minat serta mengukuhkan kefahaman murid pula, buku ini telah ditulis dengan mempelbagaikan kaedah serta corak persembahan grafik seperti penggunaan gambar foto, gambar rajah, peta i-Think, carta, graf dan ilustrasi. Akhir kata, buku teks Reka Cipta Tingkatan 5 ini diharap dapat membentuk daya imaginatif, kreatif, inovatif, inventif serta mampu merealisasikan Falsafah Pendidikan Kebangsaan dan wawasan negara. Selain itu, buku ini juga diharap mampu melahirkan generasi saintifik, progresif, berdaya fikir tinggi, berpandangan jauh, menyumbang kepada pembangunan teknologi, peka terhadap alam sekitar, mengamalkan literasi kewangan dan keusahawanan, berdaya saing serta mengagumi ciptaan Tuhan

Safety management practices in the Malaysia Technical And Vocational Education Training (TVET)

For many years, the value of safety management practice has been the subject of research attention in many sectors in Malaysia in order to achieve a positive workplace safety climate. The practice of safety management among accredited centers in the education sector, however, has hardly been examined. This study was therefore conducted in Johor, Malaysia, to investigate the elements of the safety management practices in the Technical and Vocational Education Training (TVET). This research included seven participants consisting of safety and health (SH) coordinators from each accredited TVET center in Johor, Malaysia. Via interview data collection, this study used the full qualitative approach. The outcome of the thematic analysis showed that there are ten key elements of safety management practices that have become factors among accredited TVET centers in Johor, namely management commitment, safety policy, safety committee, instructor involvement, safety rules and procedure, safety training, safety audit, risk management, communication and feedback and also safety promotion. The accredited center is advised to pay attention to these ten elements in order to improve safety management practices in the TVET sector

Estimation of corrosion resistance of curing mixtures based on coal-bearing rocks from Western Donbass

Purpose. Substantiation of possible use of coal-bearing rocks as a replacement for a part of the filler in the preparation of shotcrete for lining of mine workings in the conditions of mineralized mine water. Methods. The research is based on carrying out corrosion testing of concrete specimens by dipping them into mine water. Chemical analysis of mine waters composition has been completed. A scanning microscope was used to study the state of concrete specimens microstructure. Findings. A comparative analysis was conducted to evaluate of the cement rock resistance to mineralized water, depending on the composition of the starting components for the grouting and shotcrete mixtures is carried out. The change in the chemical composition of mine water after soaking concrete specimens in it is defined. Photographs of concrete specimens microstructure after soaking in ordinary and mineralized water for 6 and 8 months are shown. Originality. Curing mixtures based on coal-bearing rocks from Western Donbass are mineralized water resistant and can act as a quality protection from aggressive water filtrationdue to the properties of rocks used as a filler. Practical implications. The results can be used for the rational choice of the composition of the concrete mixture with the replacement of filler part with mine rock. That will enhance the long-term stability of the mine working lined by these compositions.Мета. Обґрунтування можливості використання вуглевміщуючих порід у якості заміни частини заповнювача в процесі приготування бетону для кріплення гірничих виробок в умовах мінералізованих шахтних вод. Методика. Робота базується на проведенні корозійних випробувань бетонних зразків шляхом занурення їх у шахтну воду. Виконано хімічний аналіз складу шахтних вод. Використаний растровий мікроскоп для дослідження стану мікроструктури бетонних зразків. Результати. Виконано порівняльний аналіз оцінки стійкості цементного каменю до впливу мінералізованої води залежно від складу вихідних компонентів для тампонажних, торкрет-бетонних і набризкбетонних сумішей. Визначено зміну хімічного складу шахтної води після витримки у ній бетонних зразків. Наведено фотографії мікроструктури бетонних зразків після витримки у нормальних умовах та мінералізованої води протягом 6 і 8 місяців. Наукова новизна. Твердіючі суміші на основі вуглевміщуючих порід Західного Донбасу достатньо стійкі до впливу мінералізованих вод та є якісною протифільтраційною завісою завдяки властивостям порід, використаних у якості заповнювача. Практична значимість. Отримані результати можуть бути використані для раціонального підбору складу бетонної суміші із заміною частини заповнювача шахтної породою, що дозволить підвищити тривалу стійкість гірничої виробки, закріпленої з використанням даних складів.Цель. Обоснование возможности использование углевмещающих пород в качестве замены части заполнителя в процессе приготовления бетона для крепления горных выработок в условиях минерализованных шахтных вод. Методика. Работа базируется на проведении коррозионных испытаний бетонных образцов путем погружения их в шахтную воду. Выполнен химический анализ состава шахтных вод. Использован растровый микроскоп для исследования состояния микроструктуры бетонных образцов. Результаты. Выполнен сравнительный анализ оценки устойчивости цементного камня к воздействию минерализованной воды в зависимости от состава исходных компонентов для тампонажных, торкрет-бетонных и набрызгбетонных смесей. Определено изменение химического состава шахтной воды после выдержки в ней бетонных образцов. Представлены фотографии микроструктуры бетонных образцов после выдержки в нормальных условиях и минерализованной воде в течение 6 и 8 месяцев. Научная новизна. Твердеющие смеси на основе углевмещающих пород Западного Донбасса устойчивы к влиянию минерализованных вод и являются качественной противофильтрационной завесой благодаря свойствам пород, использованных в качестве заполнителя. Практическая значимость. Полученные результаты могут быть использованы для рационального подбора состава бетонной смеси с заменой части заполнителя шахтной породой, что позволит повысить длительную устойчивость горной выработки, закрепленной с использованием данных составов.The authors express their gratitude to the administration of the Department of Construction, Geotechnics and Geomechanics of the National Mining University (Dnipropetrovsk, Ukraine), represented by O. Shashenko and A. Solodiankin, as well as to all those who helped in carrying out works related to preparation of this paper