Advances in Civil Engineering The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Hysteresis and Soil Site Dependent Input and Hysteretic Energy Spectra for Far-Source Ground Motions Tue, 06 Dec 2016 12:25:00 +0000 Earthquake input energy spectra for four soil site classes, four hysteresis models, and five ductility levels are developed for far-source ground motion effect. These energy spectra are normalized by a quantity called velocity index (VI). The use of VI allows for the creation of dimensionless spectra and results in smaller coefficients of variation. Hysteretic energy spectra are then developed to address the demand aspect of an energy-based seismic design of structures with 5% critical damping and ductility that ranges from 2 to 5. The proposed input and hysteretic energy spectra are then compared with response spectra generated using nonlinear time history analyses of real ground motions and are found to produce reasonably good results over a relatively large period range. Mebrahtom Gebrekirstos Mezgebo and Eric M. Lui Copyright © 2016 Mebrahtom Gebrekirstos Mezgebo and Eric M. Lui. All rights reserved. Influence of Local Sand on the Physicomechanical Comportment and Durability of High Performance Concrete Thu, 01 Dec 2016 11:18:42 +0000 This research consists of incorporating the crushed sand (CS) in the composition of a concrete and studies the effect of its gradual replacement by the sand dune (SD) on sustainability of high performance concrete (HPC) in aggressive environments. The experimental study shows that the parameters of workability of HPC are improved when the CS is partially replaced by the SD (<2/3). However, a high content of SD (>1/3) additional quantities of water is needed to meet the workability properties. The mechanical strengths decrease by adding the SD to CS, but they reach acceptable values with CS in moderate dosages. The HPC performances are significantly better than the control concrete made up with the same aggregates. The specification tests of durability show that the water absorbing coefficients by capillarity increase after adding SD to the CS. Nadia Tebbal and Zine El Abidine Rahmouni Copyright © 2016 Nadia Tebbal and Zine El Abidine Rahmouni. All rights reserved. Long Term Compression Strength of Mortars Produced Using Coarse Steel Slag as Aggregate Wed, 16 Nov 2016 08:55:43 +0000 The paper reports on some experimental results obtained from the production of mortars prepared using a commercial cement, coarse steelmaking slag, superplasticizer, and water. The behaviour of this reference composition was compared to that of some others containing further additives in order to investigate materials compressive strength after long time ageing. It has been demonstrated that an optimized water/cement ratio coupled with slag particles of size lower than 2.5 mm and proper protocol of preparation leads to the production of materials with good mechanical properties after 28, 90, and 180 days of ageing. The resulting materials therefore appeared as good candidates for civil engineering applications. However, the present research also demonstrates that the mortar samples of all of the compositions prepared suffer from decay and compressive strength decrease after long time ageing in water. In the present paper the results are explained taking account of materials residual porosity and alkali silica reaction which occurs in the samples. Erika Furlani and Stefano Maschio Copyright © 2016 Erika Furlani and Stefano Maschio. All rights reserved. Estimating Compressive Strength of High Performance Concrete with Gaussian Process Regression Model Wed, 12 Oct 2016 11:37:17 +0000 This research carries out a comparative study to investigate a machine learning solution that employs the Gaussian Process Regression (GPR) for modeling compressive strength of high-performance concrete (HPC). This machine learning approach is utilized to establish the nonlinear functional mapping between the compressive strength and HPC ingredients. To train and verify the aforementioned prediction model, a data set containing 239 HPC experimental tests, recorded from an overpass construction project in Danang City (Vietnam), has been collected for this study. Based on experimental outcomes, prediction results of the GPR model are superior to those of the Least Squares Support Vector Machine and the Artificial Neural Network. Furthermore, GPR model is strongly recommended for estimating HPC strength because this method demonstrates good learning performance and can inherently express prediction outputs coupled with prediction intervals. Nhat-Duc Hoang, Anh-Duc Pham, Quoc-Lam Nguyen, and Quang-Nhat Pham Copyright © 2016 Nhat-Duc Hoang et al. All rights reserved. Advancements in Design, Analysis, and Retrofitting of Structures Exposed to Blast Tue, 04 Oct 2016 11:48:52 +0000 Chiara Bedon, Claudio Amadio, Li Chen, Vasant Matsagar, Frank Wellershoff, and Xihong Zhang Copyright © 2016 Chiara Bedon et al. All rights reserved. Durability to Chemical Attack by Acids of Epoxy Microconcretes by Comparison to Cementitious Ones Thu, 29 Sep 2016 16:16:32 +0000 This research deals with the durability of micropolymer concrete (MPC) obtained by mixing an epoxy resin with fine and coarse sand particles. In particular the resistance of the micropolymer concrete to chemical solutions (citric acid C6H8O7, sulfuric acid H2SO4, and hydrochloric acid HCl) is investigated and compared to this of Portland cement microconcrete. Two MPC are tested. The first is formulated with 9% mass fraction of epoxy polymer whereas calcareous fillers have been incorporated in the second formulation in order to reduce the percentage of the epoxy binder. It is shown that a microconcrete designed with 7% of epoxy, 10% of fillers, and 83% of aggregates is characterized by higher physical and mechanical properties than those of the MPC formulated with 9% of epoxy binder. The mechanical properties of the resulting materials after their exposure to the three selected acid solutions at different durations were studied through compressive, three points bending and ultrasonic wave propagation tests. The obtained results are compared to those of microcement concretes (MCC) tested under the same conditions as MPC. The results show that both microepoxy polymer concretes exhibit better mechanical properties and highest resistance to chemical attack than the microcement concrete. Elhem Ghorbel and Murhaf Haidar Copyright © 2016 Elhem Ghorbel and Murhaf Haidar. All rights reserved. Blast Protection of Unreinforced Masonry Walls: A State-of-the-Art Review Wed, 21 Sep 2016 12:51:02 +0000 The recent rise of terrorist attacks has reinforced the need for mitigation of damage caused by blast loading on unreinforced masonry walls. The primary goal of the techniques is to prevent the loss of life while simultaneously preserving the integrity of the structure. This paper presents a compilation of recently available literature on blast protection of unreinforced masonry walls. It seeks to present the state of the art in this field, including mitigation techniques considered as well as testing methods selected. Fiber reinforced polymers and polyurea are the two dominant retrofitting techniques being assessed in the field. Other techniques include but are not limited to polyurethane, steel sheets, and aluminum foam. Since there is no widely implemented standard for blast loading test procedures, direct comparisons between the efficiencies of the mitigation techniques proposed are not always feasible. Although fragmentation is an indicator of the efficiency of retrofits, it is currently measured by subjective observation of postblast debris. Lucas Lantz, Joshua Maynez, Wesley Cook, and Claudia Mara Dias Wilson Copyright © 2016 Lucas Lantz et al. All rights reserved. Fracture Mechanics Models for Brittle Failure of Bottom Rails due to Uplift in Timber Frame Shear Walls Tue, 20 Sep 2016 08:00:07 +0000 In partially anchored timber frame shear walls, hold-down devices are not provided; hence the uplift forces are transferred by the fasteners of the sheathing-to-framing joints into the bottom rail and via anchor bolts from the bottom rail into the foundation. Since the force in the anchor bolts and the sheathing-to-framing joints do not act in the same vertical plane, the bottom rail is subjected to tensile stresses perpendicular to the grain and splitting of the bottom rail may occur. This paper presents simple analytical models based on fracture mechanics for the analysis of such bottom rails. An existing model is reviewed and several alternative models are derived and compared qualitatively and with experimental data. It is concluded that several of the fracture mechanics models lead to failure load predictions which seem in sufficiently good agreement with the experimental results to justify their application in practical design. Joergen L. Jensen, Giuseppe Caprolu, and Ulf Arne Girhammar Copyright © 2016 Joergen L. Jensen et al. All rights reserved. Erratum to “Modeling of Hydrophysical Properties of the Soil as Capillary-Porous Media and Improvement of Mualem-Van Genuchten Method as a Part of Foundation Arrangement Research” Wed, 14 Sep 2016 13:03:22 +0000 Vitaly Terleev, Aleksandr Nikonorov, Vladimir Badenko, Inna Guseva, Yulia Volkova, Olga Skvortsova, Sergey Pavlov, and Wilfried Mirschel Copyright © 2016 Vitaly Terleev et al. All rights reserved. Flutter Derivatives Identification and Aerodynamic Performance of an Optimized Multibox Bridge Deck Sun, 04 Sep 2016 13:24:53 +0000 The bridge deck sections used for long-span suspension bridges have evolved through the years, from the compact box deck girders geometrical configurations to twin-box and three-box bridge decks sections. The latest generation of split and multiple-box bridge decks proved to have better aerodynamic behavior; thus further optimization methods are sought for such geometrical configurations. A new type of multibox bridge deck, consisting of four aerodynamically shaped deck boxes, two side decks for the traffic lanes and two middle decks for the railway traffic, connected between them by stabilizing beams, was tested in the wind tunnel for identifying the flutter derivatives and to verify the aerodynamic performance of the proposed multibox deck. Aerodynamic static force coefficients were measured for the multibox bridge deck model, scaled 1 : 80, for Reynolds numbers up to 5.1 × 105, under angles of attack between −8° and 8°. Iterative Least Squares (ILS) method was employed for identifying the flutter derivatives of the multibox bridge deck model, based on the results obtained from the free vibration tests and based on the frequency analysis the critical flutter wind speed for the corresponding prototype of the multibox bridge was estimated at 188 m/s. Zhida Wang and Elena Dragomirescu Copyright © 2016 Zhida Wang and Elena Dragomirescu. All rights reserved. Experimental Study of the Effectiveness of Sacrificial Cladding Using Polymeric Foams as Crushable Core with a Simply Supported Steel Beam Sun, 04 Sep 2016 10:14:05 +0000 The present paper focuses on the study of the effectiveness of the sacrificial cladding using polymeric foam as crushable core to reduce the delivered blast energy using a simplified structure. The latter consists of a simply supported steel beam under a localized blast load. The tested sacrificial cladding has a cross-sectional area of 80 × 80 mm2. The effect of the front plate mass and the crushable core properties (plateau stress and thickness) is studied. Three polymeric foams are investigated: (a) the expanded polystyrene foam (PS13) with a density of 13 kg/m3, (b) the closed-cell polyurethane (PU30) with a density of 30 kg/m3, and (c) the open-cell polyurethane (PU50) with a density of 50 kg/m3. Four front plate masses are used: 144, 188, 336, and 495 g. All possible combinations are tested to determine their absorption capacity. The obtained results show that the absorption capability increases by increasing the front plate mass, the plateau stress, and the thickness of the crushable core. The open-cell polyurethane PU50 performs better. Disintegration problems are observed on the expanded polystyrene PS13 after the end of the compression process. H. Ousji, B. Belkassem, M. A. Louar, B. Reymen, L. Pyl, and J. Vantomme Copyright © 2016 H. Ousji et al. All rights reserved. Clever House Made by Using a New Kind of the Nanocomposites Thu, 01 Sep 2016 11:49:10 +0000 The materials of this paper concern a new nanocomposites perspective for construction. The development of research in the field of production and application of nanocomposite materials has made it possible to develop building materials, having high exploitation characteristics. One of such materials is a polydisperse armed water soluble epoxy composite coat, named “EpoxyPAN.” This material consists of the water soluble epoxy resin filled by the high strength inorganic fillers and the unique nanocarbon particles, astralenes and nanoporous microfiber. It was found that EpoxyPAN is possible to be used as effective water protection coating and simultaneously as effective electromagnetic waves absorber. The physical and exploitation properties of this nanocomposite and the possible ways of its applications for the Clever House constructions are also described in this paper. Andrey Ponomarev and Timur Plavnik Copyright © 2016 Andrey Ponomarev and Timur Plavnik. All rights reserved. Crystalline Coating and Its Influence on the Water Transport in Concrete Thu, 11 Aug 2016 13:25:54 +0000 The presented paper deals with an experimental study of the efficiency of surface coating treatment based on secondary crystallization as an additional protection of the subsurface concrete structure loaded by moisture or ground water pressure. The aim of the experimental program was the evaluation of the depth impact of the crystalline coating and the assessment of the reliability of construction joints performed on models simulating real conditions of the concrete structure. The evolution of the secondary crystallizing process was monitored using the water absorption test carried out at different depths of the samples. The coefficient of adsorption decreased to 60% of the reference mixture for a surface layer of up to 40 mm at 28 days and to 50% at 180 days after the coating’s application. Furthermore, the electrical resistivity method was applied with respect to the nature of measurement and the low accessibility of real subsurface concrete structures. The results of moisture measurement at a depth of 180–190 mm from the surface treated with a crystalline coating showed an essential decrease in moisture content percentage in comparison with untreated specimens (measured 125 days after the coating’s application). Pavel Reiterman and Jiri Pazderka Copyright © 2016 Pavel Reiterman and Jiri Pazderka. All rights reserved. Modelling Blast Effects on a Reinforced Concrete Bridge Wed, 10 Aug 2016 13:55:00 +0000 The detailed investigation of blast phenomena and their catastrophic effects on existing structures are the main objectives of the present paper. It is well known that blast phenomena may be characterized by significant complexity, often involving complicated wave propagation effects as well as distinguishable material behaviors. Considering the above and in an attempt to provide a simplified modelling approach for the simulation of blast effects, a novel procedure is presented herein based on well-established methodologies and common engineering practices. In the above framework, firstly, the “predominant” deformation shape of the structure is estimated based on elastic finite element simulations under blast loads and then the structural response of the system is evaluated as a result of common computational beam-element tools such as displacement-based pushover analysis. The proposed methodology provides an immediate first estimation of the structural behavior under blast loads, based on familiar engineering procedures. A two-span reinforced concrete bridge was thoroughly investigated and the results provide insightful information regarding the damage patterns and localization. Markellos Andreou, Anastasios Kotsoglou, and Stavroula Pantazopoulou Copyright © 2016 Markellos Andreou et al. All rights reserved. Bioinspired Design of Building Materials for Blast and Ballistic Protection Wed, 10 Aug 2016 11:08:30 +0000 Nacre in abalone shell exhibits high toughness despite the brittle nature of its major constituent (i.e., aragonite). Its specific structure is a major contributor to the energy absorption capacity of nacre. This paper reviews the mechanisms behind the performance of nacre under shear, uniaxial tension, compression, and bending conditions. The remarkable combination of stiffness and toughness on nacre can motivate the development of bioinspired building materials for impact resistance applications, and the possible toughness designs of cement-based and clay-based composite materials with a layered and staggered structure were discussed. Yu-Yan Sun, Zhi-Wu Yu, and Zi-Guo Wang Copyright © 2016 Yu-Yan Sun et al. All rights reserved. Design of Blast-Loaded Glazing Windows and Facades: A Review of Essential Requirements towards Standardization Sun, 07 Aug 2016 07:07:24 +0000 The determination of the blast protection level of laminated glass windows and facades is of crucial importance, and it is normally done by using experimental investigations. In recent years numerical methods have become much more powerful also with respect to this kind of application. This paper attempts to give a first idea of a possible standardization concerning such numerical simulations. Attention is drawn to the representation of the blast loading and to the proper description of the behaviour of the material of the mentioned products, to the geometrical meshing, and to the modelling of the connections of the glass components to the main structure. The need to validate the numerical models against reliable experimental data, some of which are indicated, is underlined. Martin Larcher, Michel Arrigoni, Chiara Bedon, J. C. A. M. van Doormaal, Christof Haberacker, Götz Hüsken, Oliver Millon, Arja Saarenheimo, George Solomos, Laurent Thamie, Georgios Valsamos, Andy Williams, and Alexander Stolz Copyright © 2016 Martin Larcher et al. All rights reserved. Effects of Asphalt Mix Design Properties on Pavement Performance: A Mechanistic Approach Tue, 02 Aug 2016 11:14:28 +0000 The main objective of this study was to investigate the effects of hot mix asphalt material properties on the performance of flexible pavements via mechanistic approach. 3D Move Analysis software was utilized to determine rutting and cracking distresses in an asphalt concrete (AC) layer. Fourteen different Superpave mixes were evaluated by utilizing results of the Dynamic Modulus () Test and the Dynamic Shear Modulus () Test. Results showed that with the increase of binder content, the tendency of rutting in AC layer increased. However, with the increase of binder content, the cracking of AC layer lessened. Furthermore, when different binder grades were evaluated, results showed that with the increase of the upper binder grade number, rutting decreased, and with the increase of the lower binder grade number, rutting increased. Furthermore, analysis showed that with the increase of the lower binder grade number, higher percent of bottom up cracks would result. As a result of the analysis, binder grade should not be solely considered for cracking in AC layer; binder content and aggregate structure play a big role. Finally, results illustrated that the mechanistic approach is a better tool to determine the performance of asphalt pavement than commonly used methods. Ahmad M. Abu Abdo and S. J. Jung Copyright © 2016 Ahmad M. Abu Abdo and S. J. Jung. All rights reserved. Study on Compressive Strength of Quarry Dust as Fine Aggregate in Concrete Thu, 28 Jul 2016 06:59:12 +0000 The concept of replacement of natural fine aggregate by quarry dust which is highlighted in the study could boost the consumption of quarry dust generated from quarries. By replacement of quarry dust, the requirement of land fill area can be reduced and can also solve the problem of natural sand scarcity. The availability of sand at low cost as a fine aggregate in concrete is not suitable and that is the reason to search for an alternative material. Quarry dust satisfies the reason behind the alternative material as a substitute for sand at very low cost. It even causes burden to dump the crusher dust at one place which causes environmental pollution. From the results of experimental investigations conducted, it is concluded that the quarry dust can be used as a replacement for fine aggregate. It is found that 40% replacement of fine aggregate by quarry dust gives maximum result in strength than normal concrete and then decreases from 50%. The compressive strength is quantified for varying percentage and grades of concrete by replacement of sand with quarry dust. K. Shyam Prakash and Ch. Hanumantha Rao Copyright © 2016 K. Shyam Prakash and Ch. Hanumantha Rao. All rights reserved. Study on Mechanical Features of Brazilian Splitting Fatigue Tests of Salt Rock Wed, 27 Jul 2016 13:21:24 +0000 The microtest, SEM, was carried out to study the fracture surface of salt rock after the Brazilian splitting test and splitting fatigue test were carried out with a servo-controlled test machine RMT-150B. The results indicate that the deviation of using the tablet splitting method is larger than that of using steel wire splitting method, in Brazilian splitting test of salt rock, when the conventional data processing method is adopted. There are similar deformation features in both the conventional splitting tests and uniaxial compression tests. The stress-strain curves include compaction, elasticity, yielding, and failure stage. Both the vertical deformation and horizontal deformation of splitting fatigue tests under constant average loading can be divided into three stages of “loosening-tightness-loosening.” The failure modes of splitting fatigue tests under the variational average loading are not controlled by the fracturing process curve of the conventional splitting tests. The deformation extent of fatigue tests under variational average loading is even greater than that of conventional splitting test. The tensile strength of salt rock has a relationship with crystallization conditions. Tensile strength of thick crystal salt rock is lower than the bonded strength of fine-grain crystals. Weichao Wang, Mengmeng Wang, and Xiliang Liu Copyright © 2016 Weichao Wang et al. All rights reserved. Plasticity, Swell-Shrink, and Microstructure of Phosphogypsum Admixed Lime Stabilized Expansive Soil Thu, 21 Jul 2016 08:01:47 +0000 The study involved utilization of an industrial waste, Phosphogypsum (PG), as an additive to lime stabilization of an expansive soil. Three lime dosages, namely, initial consumption of lime (ICL), optimum lime content (OLC), and less than ICL (LICL), were identified for the soil under study for stabilizing the soil. Along with lime, varying doses of PG were added to the soil for stabilization. The effect of stabilization was studied by performing index tests, namely, liquid limit, plastic limit, shrinkage limit, and free swell test, on pulverized remains of failed unconfined compression test specimens. The samples were also subjected to a microstructural study by means of scanning electron microscope. Addition of PG to lime resulted in improvement in the plasticity and swell-shrink characteristics. The microstructural study revealed the formation of a dense compact mass of stabilized soil. Jijo James and P. Kasinatha Pandian Copyright © 2016 Jijo James and P. Kasinatha Pandian. All rights reserved. Advanced Concrete Model in Hydrocode to Simulate Concrete Structures under Blast Loading Tue, 05 Jul 2016 09:57:44 +0000 The formulations of the advanced concrete RHT model adopted in AUTODYN are investigated and numerical studies are conducted to study the RHT model’s actual performances under various loading conditions. It is found that using of default values in the RHT model is not able to simulate the realistic behavior of concrete under various loading conditions. Thus modified parameters in the RHT model are proposed to better capture the realistic behavior of concrete under such loading conditions. Furthermore, numerical simulation of normal concrete slabs and multilayer concrete slabs subjected to blast loading is conducted using AUTODYN with both the default and modified RHT parameters. Experimental readings from field blast tests are used to validate the numerical model developed. It is shown that the results from numerical simulations using the modified RHT parameters and the measurements from the field blast test agree well in terms of damage pattern, crater diameter, and acceleration. Hence, it can be concluded that the RHT model with modified parameters can capture the mechanical behavior of concrete structures well. The validated model can be further used to conduct a parametric study on the influence of key parameters (i.e., compressive strength, fracture energy, and thickness) on blast resistance of concrete structure. Guo Hu, Jun Wu, and Liang Li Copyright © 2016 Guo Hu et al. All rights reserved. Strength and Deformability of Fiber Reinforced Cement Paste on the Basis of Basalt Fiber Thu, 30 Jun 2016 12:18:06 +0000 The research object of the paper is cement paste with the particulate reinforcement of basalt fiber. Regardless of fibers’ length at the same fiber cement mix workability and cement consumption equality compressive solidity of the specimens is reduced with increasing fiber content. This is due to the necessity to increase the water-cement ratio to obtain a given workability. The flexural stability of the specimens with increasing fiber content increments in the same conditions. There is an optimum value of the fibers’ dosage. That is why stability has a maximum when crooking. The basaltic fiber particulate reinforcement usage can abruptly increase the cement paste level limiting extensibility, which is extremely important in terms of crack resistance. Yury Barabanshchikov and Ilya Gutskalov Copyright © 2016 Yury Barabanshchikov and Ilya Gutskalov. All rights reserved. Design of Normal Concrete Mixtures Using Workability-Dispersion-Cohesion Method Mon, 20 Jun 2016 13:54:34 +0000 The workability-dispersion-cohesion method is a new proposed method for the design of normal concrete mixes. The method uses special coefficients called workability-dispersion and workability-cohesion factors. These coefficients relate workability to mobility and stability of the concrete mix. The coefficients are obtained from special charts depending on mix requirements and aggregate properties. The method is practical because it covers various types of aggregates that may not be within standard specifications, different water to cement ratios, and various degrees of workability. Simple linear relationships were developed for variables encountered in the mix design and were presented in graphical forms. The method can be used in countries where the grading or fineness of the available materials is different from the common international specifications (such as ASTM or BS). Results were compared to the ACI and British methods of mix design. The method can be extended to cover all types of concrete. Hisham Qasrawi Copyright © 2016 Hisham Qasrawi. All rights reserved. Modified Liu-Carter Compression Model for Natural Clays with Various Initial Water Contents Mon, 20 Jun 2016 09:39:01 +0000 The initial water content has a significant effect on the compression behaviour of reconstituted clays. This effect has to be considered in the Liu-Carter model to ensure the addition voids ratio only related to soil structure. A modified Liu-Carter compression model is proposed by introducing the empirical equations for reconstituted clays at different initial water contents into the Liu-Carter model. The proposed model is verified against the experimental results from the literature. The simulations by the proposed method are also compared with that by old method where the influence of initial water content is not considered. The results show that the predicted virgin compression curves of natural clays are similar, but the values of and may be very different. Sen Qian, Jian Shi, and Jian-wen Ding Copyright © 2016 Sen Qian et al. All rights reserved. Elaboration of the Method for Safety Assessment of Subsea Pipeline with Longitudinal Buckling Thu, 19 May 2016 11:18:30 +0000 The issue of ensuring longitudinal stability of marine gas pipelines has been raised in view of construction of pipelines operating at significant temperature drops. Most commonly the pipelines deviation from the design conditions as well as equilibrium disturbance occurs due to longitudinal buckling. The task of designing the marine gas pipeline involves making the reliability analysis of the pipeline, taking into account the required conditions of structural reliability in all construction phases. As per the Russian standards, the vertical buckling is not considered in the stability analysis, whereas the standards of the USA, Norway (DNV-RP-F110), and the Great Britain emphasize the need for considering the lateral buckling caused by axial forces. This paper focuses on the operational reliability calculation for an underwater main gas pipeline, in which longitudinal buckling failure occurred. The calculation is based on the probabilistic and statistical method of assessing the pipeline state and operational reliability. Liudmila Muravyeva and Nikolai Vatin Copyright © 2016 Liudmila Muravyeva and Nikolai Vatin. All rights reserved. Hydraulic Conductivity of Compacted Laterite Treated with Iron Ore Tailings Mon, 16 May 2016 07:57:38 +0000 The objective of this study was to investigate the effect of iron ore tailings (IOT) on hydraulic conductivity of compacted laterite. The IOT conforms to ASTM C 618-15 Type F designations. In the present study, soil was admixed with 0–20% IOT and compacted at moulding water content ranging from 10 to 25% using four types of compactive efforts. Hydraulic conductivities of the compacted soil-IOT mixtures were determined using deionized water and municipal solid waste leachate as the permeant fluids, respectively. Deionized water was the reference permeant fluid. Results of this study showed that hydraulic conductivity decreased with increase in IOT content as a result of improvement in mechanical properties of the soil. Permeation of the soil-IOT mixtures with leachate caused the hydraulic conductivity to drop to less than 1 × 10−9 m/s especially at higher compactive efforts. Also, bioclogging of the soil pores due to accumulation of biomass from bacteria and yeast present in the leachate tends to significantly reduce the hydraulic conductivity. From an economic point of view, it has been found from the results of this study that soil specimens treated with up to 20% IOT and compacted at the British Standard Light (BSL) compactive effort met the maximum regulatory hydraulic conductivity of less than or equal to 1 × 10−9 m/s for hydraulic barrier system. Umar Sa’eed Yusuf, Matawal Danladi Slim, and Elinwa Augustine Uchechukwu Copyright © 2016 Umar Sa’eed Yusuf et al. All rights reserved. The Application of Equivalent Age Concept to Sand Concrete Compared to Ordinary Concrete Sun, 08 May 2016 14:34:30 +0000 In this research the equivalent age concept was used, in order to simulate strength development of heat treated sand concrete compared with ordinary concrete at different temperature, 35, 55, and 70°C, and validate the simulation results with our experimental results. Sand concrete is a concrete with a lower or without coarse aggregate dosage; it is used to realize thin element as small precast prestressed beams, in injected concrete or in regions where sand is in extra quantity and the coarse aggregate in penury. This concrete is composed by principally sand, filler, superplasticizer, water, and cement. The results show that the simulation of ordinary concrete was acceptable with an error lower than 20%. But the error was considerable for the sand concrete. The error was due to large superplasticizer dosage, which modified the hardening of sand concrete; the most influent parameter in Arrhenius law is apparent energy activation, to search for the value of the activation energy which gives the best simulation; a superposition is used of two curves of different temperature and with superplasticizer dosage 4% and several values of activation energy, 15, 20, 25, and 30 × 10 kcal. The simulation becomes ameliorated with the adequate value of activation energy. Nabil Bella, Ilham Aguida Bella, and Aissa Asroun Copyright © 2016 Nabil Bella et al. All rights reserved. GIS Based Approach for Vulnerability Assessment of the Karnataka Coast, India Sun, 08 May 2016 11:40:43 +0000 The coastal zones are highly resourceful and dynamic. In recent times, increased events of tropical cyclones and the devastating impact of the December 2004 tsunami have brought forth the importance of assessing the vulnerability of the coast to hazard-induced flooding and inundation in coastal areas. This study intends to develop coastal vulnerability index (CVI) for the administrative units, known as talukas of the Karnataka state. Seven physical and geologic risk variables characterizing the vulnerability of the coast, including rate of relative sea level change, historical shoreline change, coastal slope, coastal regional elevation, mean tidal range, and significant wave height derived using conventional and remotely sensed data, along with one socioeconomic parameter “population,” were used in the study. A total of 298 km of shoreline are ranked in the study. It was observed that about 68.65 km of the shoreline is under very high vulnerable category and 79.26 km of shoreline is under high vulnerable category. Of the remaining shoreline, 59.14 km and 91.04 km are of moderate and low vulnerable categories, respectively. Akshaya Beluru Jana and Arkal Vittal Hegde Copyright © 2016 Akshaya Beluru Jana and Arkal Vittal Hegde. All rights reserved. Modeling of Hydrophysical Properties of the Soil as Capillary-Porous Media and Improvement of Mualem-Van Genuchten Method as a Part of Foundation Arrangement Research Wed, 06 Apr 2016 08:01:59 +0000 Within the concepts about the capillarity and the lognormal distribution of effective pore radii, a theoretical justification for function of differential water capacity and its antiderivative (function of water-retention capacity in form of a dependence of the soil volumetric water content on capillary pressure of the soil moisture) is presented. Using these functions, the ratio of soil hydraulic conductivity function to the filter coefficient is calculated. Approximations to functions describing the water-retention capacity and relative hydraulic conductivity of the soil have been suggested. Parameters of these functions have been interpreted and estimated with applying the physical and statistical indices of the soil. Vitaly Terleev, Aleksandr Nikonorov, Vladimir Badenko, Inna Guseva, Yulia Volkova, Olga Skvortsova, Sergey Pavlov, and Wilfried Mirschel Copyright © 2016 Vitaly Terleev et al. All rights reserved. Design of Reverse Curves Adapted to the Satellite Measurements Tue, 05 Apr 2016 12:34:26 +0000 The paper presents a new method for designing railway route in the direction change area adapted to the Mobile Satellite Measurements technique. The method may be particularly useful in the situations when both tangents cannot be connected in an elementary way using a circular arc with transition curves. Thus, the only solution would be the application of two circular arcs of opposite curvature signs, that is, the use of an inverse curve. It has been assumed that the design of the geometrical layout will take place within an adequate local coordinate system. The solution of the design problem takes advantage of a mathematical notation and concentrates on the determination of universal equations describing the entire geometrical layout. This is a sequential operation involving successive parts of the mentioned layout. This universal algorithm can be easily applied to the computer software which will allow generating, in an automatic way, other geometrical layouts. Then, the choice of the most beneficial variant from the point of obtained trains velocities while minimizing the track axis offsets will be held using the optimization techniques. The current designing methods do not provide such opportunities. The presented method has been illustrated by appropriate calculation examples. Wladyslaw Koc Copyright © 2016 Wladyslaw Koc. All rights reserved.