14 Articles Published

1. TUNNELLING BENEATH PILED STRUCTURES (BASED ON MOHR–COULOMB CRITERION)

Authors: A. F. ZIDAN , O.M.O. RAMADAN

Abstract: This paper investigates the interaction between tunnelling in soft soil and adjacent piled structure. Several three-dimensional finite element analyses are performed to study the deformation of pile caps and piles during the construction of a nearby tunnel. The comparison between free field analyses with those of coupled analyses is also presented. To simulate the tunnelling process and its effects on piled structures, one symmetric half of the soil medium, the tunnelling boring machine, face pressure, the final tunnel lining, the pile caps, and the piles are modelled in several construction phases. The paper is organized into three parts: the first part describes the adopted numerical model; the second part investigates the response of pile caps during tunnelling; and the last part is concerned with the deformation of piles in the presence of the superstructure.

Keywords: Finite element, tunnelling, soil structure interaction, pile foundation, three-dimensional analysis

Pages: 1 - 4 | DOI: 10.15224/978-1-63248-101-6-01

2. VALIDITY OF USING BAMBOO AS REINFORCEMENT OF CONCRETE BEAMS

Authors: EMAN EL-TAHAN , MOHAMMAD MOHIE ELDIN

Abstract: Natural fibers, including the Bamboo, are environment friendly materials. They require a low degree of industrialization and a small energy for their processing and production, and hence the total fabricating cost is also low. The main purpose of this paper is to cover the lack of information about Bamboo; its mechanical properties, interaction with concrete, strength and durability, and to investigate its validity of replacing steel as a reinforcement of concrete beams. This possibility is investigated through experimental results of bamboo reinforced concrete beams compared with others reinforced using steel. The experimental results were verified and expanded using the FE package called ANSYS. In this research, the Bamboo was used without any treatment or stirrups. It was found that untreated Bamboo must not be used as reinforcement in concrete beams, although its mechanical properties may be considered as comparable to steel.

Keywords: Bamboo, Reinforcement, concrete, ANSYS

Pages: 5 - 10 | DOI: 10.15224/978-1-63248-101-6-02

3. SHEAR TRANSFER IN COMPOSITE CONCERTE-CONCERTE T-SECTION

Authors: ABDALLH MOSTAFA SOLIMAN , MOHAMED RABIE MAHMOUD , WAEL SALAH ELDIN ZAKI

Abstract: The problem of shear transfer between different types of concrete surface cast at different ages has been discussed in many researches. Different types of surface treatments and shear connectors were studied experimentally to test their efficiency in what is called the (composite section) which could be formed between a precast beam and cast in place slab. In this research eleven composite concrete-concrete T-section with dimensions (beam 120*400*2000mm and slab 500*100*2000mm) were tested under static concentrated load in the middle of the span, one of them was reference monolithic T-section and the other were with different types of surface treatment like shear connectors with different lengths, epoxy and roughening also the effect of concrete strength was studied to obtain the best way to transfer the shear between concrete layers.

Keywords: Concrete, Shear Connectors, Pre-slabs, shear transfer, Interface roughness

Pages: 11 - 15 | DOI: 10.15224/978-1-63248-101-6-03

4. LENGTH OF FLOW SEPARATION

Authors: M. F. SAUIDA

Abstract: Flow separation is a natural phenomenon encountered at some cases downstream of multi-vent regulators. The main flow is divided into current flow and dead zone flow (reverse flow and weak forward flow). The length of flow separation must be taken into consideration downstream of regulators for canal side’s protection and accurate flow measurement. The present study aims to analyze the flow separation downstream of regulators in sudden expanding stilling basin. An extensive experimental program has been conducted on a regulator model of five vents at the Hydraulic Research Institute (HRI). Empirical model based on the results of the dimensional analysis is proposed within this study to compute the dimensionless length of separation by using multiple linear regression analysis. Results revealed that the empirical model proposed can be used for practical applications in canal side’s protection and flow measurements downstream of hydraulic structures.

Keywords: separation of flow, length of flow separation, sudden expanding channel, hydraulic structures, and velocity vectors.

Pages: 16 - 21 | DOI: 10.15224/978-1-63248-101-6-04

5. EXPERIMENTAL TESTS OF LOCAL SCOUR AT CIRCULAR RIVER PIERS WITH TRUNCATED CONE FOUNDATION

Authors: C. CIARAVINO , G. CIARAVINO

Abstract: Stream flow in mobile river beds gives rise to scour phenomena around river piers that may jeopardize the stability of the bridge. As scour is dependent on pier shape (among other factors), estimating equations generally introduce shape coefficients. In the present study experimental tests concerning scour phenomena have been carried out on a particular shape of the already effective circular piers in order to determine if any improvement is verified in their shape coefficient (with a corresponding decrease in scour). In particular, the circular pier foundation has been shaped as a truncated cone, partially or totally sunk into the mobile bed. In the experimental tests a preliminary comparison has been effected between scour at uniform circular pier and non uniform piers with two different values of bevel angle for the truncated cone foundation. Experimental results have showed that, for both values, the scour depth has been lower than that identified in experimental tests conducted on

Keywords: scour phenomena, mobile bed, river piers, bridge stability.

Pages: 22 - 26 | DOI: 10.15224/978-1-63248-101-6-05

6. SLAB APPLICATION OF FIBER REINFORCED LIGHTWEIGT CONCRETE

Authors: BENGI ARISOY

Abstract: In this paper slab application of propylene reinforced lightweight concrete is discussed. The effect of fibers on flexural strength of lightweight concrete was investigated and possible slab use of propylene fiber reinforced lightweight concrete was discussed. In the frame work of the study, fiber reinforced lightweight concrete was produced with using short propylene fibers, lightweight aggregate (perlite), cement, sand, plasticizer and water. Propylene fibers are used provide ductility in place of steel reinforcement. Perlite used as aggregate provides lightweight. Cement and sand component are used for strength. The cube, cylinder and beam samples were prepared to determine material and mechanical properties of fiber reinforced lightweight concrete. Possible use of fiber reinforced lightweight concrete as slab; the slabs (panels) with the dimension of 13x50x150cm were produced. The panels were tested in four-point bending test to determine flexural strength (MOR, modulus of rupture)

Keywords: ductility, fiber reinforced concrete, lightweight concrete, slabs

Pages: 27 - 29 | DOI: 10.15224/978-1-63248-101-6-06

7. EXPERIMENTAL EVALUATION OF E-STUBS UNDER SHEAR

Authors: A. LOUREIRO , J. M. REINOSA , M.LOPEZ , R. GUTIERREZ

Abstract: Current European standard of steel structures (Eurocode 3), establishes the necessity of taking into account the rigidity and resistance of joints in the overall calculation of the structure. This normative uses the method of the components. One of the components with greater influence on the behavior of the joint is the column web in shear. In 3D joints with additional plates, a new component, called E-Stub, appears. This component has been studied in regards to their behavior under axial load. However, the behavior of the E-stub when it is subjected to shear, has not been yet studied. In the present work, a test of a 3D joint with additional plates subjected to shear forces is conducted. During this process, measurements of strain gauges, inclinometers, and load cells are carried out. In this way, it is possible to determine the moment_rotation curves of the different panels composing the joint (web of the column and additional plates). The test is con- ducted in the elastic range, i

Keywords: E-stub, Experimental Evaluation, Semirigid Joints, Method of the Components.

Pages: 30 - 33 | DOI: 10.15224/978-1-63248-101-6-07

8. MECHANICAL MODEL FOR 2D STEEL JOINTS WITH BEAMS OF DIFFERENT DEPTH WITHOUT WEB STIFFENERS.

Authors: A. LOUREIRO , J. M. REINOSA , M.LOPEZ

Abstract: Joints play a very important role in steel structures from the points of view of safety and optimization. In recent years progress has been made in the characterization of the behaviour of steel joints. Part of the knowledge has been integrated in the design codes, and EC3 in particular. In this code the component method has been proposed for connection analysis. However, not all the possible cases are included. One of the configurations that need to be studied is the joint studied in this research: it is a welded internal joint with beams of different depth and without stiffeners. A parametric analysis, based on previously calibrated finite element models is carried out. From the results of this analysis, the expressions for the components that form the mechanical model of the joint are proposed.

Keywords: Semirigid joints, Steel structures, Mechanical model, Parametric analysis

Pages: 34 - 37 | DOI: 10.15224/978-1-63248-101-6-08

9. BEHAVIOUR OF MULTI-LAYERED GEOCELL REINFORCED BED SUBJECTED TO REPEATED LOAD

Authors: ANDREW R. DAWSON , MAHMOUD K. MOHAMMED , OMID KHALAJ , SEYED NASER MOGHADDAS TAFRESHI

Abstract: This paper describes a series of the plate load tests performed in a test pit measuring 2000×2000 mm in plane and 700 mm in depth. To simulate traffic loadings, fifteen loading and unloading cycles were applied to the loading plate with amplitudes of 400 and 800 kPa. The optimum depth of the top most layer of geocell and the optimum vertical spacing of geocell layers, based on plate settlement, are both approximately 0.2 times loading plate diameter. The results show that installation of the geocell layers in the foundation bed decreases the accumulated plastic and total settlements of loading plate, in addition to increase its elastic settlement. Efficiency of geocell reinforcement was decreased by increasing the number of the geocell layers for all applied stress levels and number of cycles of applied loading. The results of the testing reveal the ability of the multiple layers of geocell reinforcement to ‘shakedown’ to a fully resilient behavior after a period of plastic settlement

Keywords: Cyclic loading; Multiple geocell layers; Residual and resilient deformations

Pages: 38 - 42 | DOI: 10.15224/978-1-63248-101-6-09

10. DISTRIBUTION AND ORIENTATION OF STEEL FIBRES IN STEEL FIBRE REINFORCED CONCRETE

Authors: AYMAN NASSIF , JOHN WILLIAMS , OLUBISI IGE , STEPHANIE BARNETT

Abstract: The use of fibres to reinforce brittle materials for better performance has been employed since time immemorial. Therefore, inclusion of steel fibres in concrete has always improved the post-cracking strength and concrete ductility to a large extent while full potential of steel fibre reinforced concrete (SFRC) is still yet to be exploited in practice. This study investigated the effects of fibre type, dosage and maximum aggregate size on distribution and orientation and hence, the flexural performance of steel fibre reinforced concrete. Hooked-end steel fibres with 50 mm and 60 mm length, aspect ratio of 45, 65 and 80, and dosages of 0 kg/m³, 25 kg/m³, 40 kg/m³, 50 kg/m³ and 60 kg/m³ were used with maximum sizes of coarse aggregate of 10mm and 20mm. X-ray Computed Tomography was employed for imaging cores taken from the slab specimens after testing. The experimental results show a remarkable improvements in flexural strength up to 83% observed at larger dosage of steel fibre and when

Keywords: Concrete, Flexural properties, Steel fibres, Aggregate size, Fibre distribution and orientation.

Pages: 43 - 47 | DOI: 10.15224/978-1-63248-101-6-10

11. EFFECTS OF HOOK SHAPE AND CEMENT REPLACEMENT MATERIALS ON PULLOUT BEHAVIOUR OF STEEL FIBRES

Authors: DAVID BEGG , ELYAS MALAKI ZANJANI , STEPHANIE BARNETT

Abstract: The purpose of this study is to investigate the effect of hook shape and material of high tensile strength hooked end steel fibres and the impact of cement replacement materials on pullout behaviour of steel fibres from cementitious composites. The cement replacements which have been used in this research included silica fume, pulverised fuel ash, limestone filler and ground granulated blast-furnace slag. In total, more than 800 samples have been manufactured for experimental research on compressive strength and pullout behaviour of hooked end steel fibres from cementitious matrices. The effects of parameters such as water/binder ratio, cement replacement content, age of sample, hooked end shape and tensile strength of fibre on fibre–matrix pullout behaviour were determined. The results of tests and analysis indicate that hook shape, tensile strength of fibre and silica fume affect the maximum pullout force and ground granulated blast-furnace slag can significantly improve the residual

Keywords: Steel Fibre, Pullout, Cement Replacement, Cementitious Materials

Pages: 48 - 52 | DOI: 10.15224/978-1-63248-101-6-11

12. HUMAN ACTION ON STRUCTURES: COMPARISON BETWEEN NUMERICAL LOAD MODELS AND EXPERIMENTAL DATA

Authors: A. FRAILE , E. ALARCON , J. FERNANDEZ , L. HERMANNS

Abstract: Modelling of human-induced loads has been proved to be very difficult as we can see in several approaches of varying complexity that have been presented in the literature. Crowd induced dynamic loading in large structures, such as gymnasiums or stadiums, is usually modelled as a series of harmonic loads which are defined in terms of their Fourier coefficients. Different values of these Fourier coefficients that were obtained from full scale measurements can be found in codes. In this paper, a study of loads generated by different human actions (jumping, walking and dancing) is presented. A comparison between experimental data measured with instrumented insoles and numerical data obtained with numerical models has been carried out. Tests have been performed on a structure designed to be a gymnasium, which has natural frequencies within that range of the excitation frequencies.

Keywords: human induced load, dynamic test, walking load, jumping load, dancing load, full scale test.

Pages: 53 - 57 | DOI: 10.15224/978-1-63248-101-6-12

13. THE COMPARATIVE ANALYSIS OF OPTIMAL DESIGNED WEB EXPANDED BEAMS VIA IMPROVED HARMONY SEARCH METHOD

Authors: FERHAT ERDAL , OSMAN TUNCA, , SERKAN TAS

Abstract: This study aims at comparing the optimum design of two common types open web expanded beams: with hexagonal openings, also called castellated beams and beams with circular openings referred to as cellular beams. The minimum weights of both beams are taken as the objective functions while the design constraints are respectively implemented from The Steel Construction Institute Publication Numbers 5 and 100. The design methods adopted in these publications are consistent with BS5950 parts. The formulation of the design problem considering the limitations of the above mentioned turns out to be a discrete programming problem. Improved harmony search (IHS) algorithm is suggested to compare the optimum design of mentioned web-expanded beams to analysis the performance of both beams. The design algorithms based on the technique select the optimum Universal Beam sections, dimensional properties of hexagonal and circular holes and total number of openings along the beam as design variables.

Keywords: structural optimization, web expanded beams, castellated beams, cellular beams, harmony search algorithm

Pages: 68 - 72 | DOI: 10.15224/978-1-63248-101-6-56

14. SUITABILITY OF NANO-CHEMICAL STABILIZER IN BLACK COTTON SOIL

Authors: B. L. SWAMI , PRACHI KUSHWAHA , ROOPIKA SRIVASTAVA

Abstract: Construction and subsequent maintenance of pavements in good condition has become quite problematic During monsoon season the natural subgrade soils become soft and pose serious problem ,To the movement of vehicular traffic, Instead of cutting out and replacing the unstable soil, soil adjustment is the only alternative as it saves lot of time and millions of money too. Soil adjustment can be defined as the change of the soil properties by synthetic or physical means keeping in mind the end goal to improve the designing nature of the soil. This paper presents the result of comprehensive laboratory investigation over behaviour of stabilised black cotton soil using Terrasil and Zycobond as nano- chemical based stabiliser. The soil is stabilised in different proportions and combination of Terrasil and Zycobond.

Keywords: Terrasil, Zycobond, clay soil, UCS, CBR

Pages: 73 - 76 | DOI: 10.15224/978-1-63248-101-6-77