The importance of understanding computer analyses in civil engineering

Sophisticated computer modelling systems are widely used in civil engineering analysis. This paper takes examples from structural engineering, environmental engineering, flood management and geotechnical engineering to illustrate the need for civil engineers to be competent in the use of computer tools. An understanding of a model's scientific basis, appropriateness, numerical limitations, validation, verification and propagation of uncertainty is required before applying its results. A review of education and training is also suggested to ensure engineers are competent at using computer modelling systems, particularly in the context of risk management. 1. Introductio

Applications of topology optimisation in structural engineering: high-rise buildings & steel components

This study introduces applications of structural topology optimization to buildings and civil engineering structures. Topology optimization problems utilize the firmest mathematical basis, to account for improved weight-to-stiffness ratio and perceived aesthetic appeal of specific structural forms, enabling the solid isotropic material with penalization (SIMP) technique. Structural topology optimization is a technique for finding the optimum number, location and shape of “openings” within a given continuum subject to a series of loads and boundary conditions. Aerospace and automotive engineers routinely employ topology optimization and have reported significant structural performance gains as a result. Recently, designers of buildings and structures have also started investigating the use of topology optimization, for the design of efficient and aesthetically pleasing developments. This paper examines two examples of where topology optimization may be a useful design tool in civil/structural engineering in order to overcome the frontiers between civil engineers and engineers from other disciplines. The first example presents the optimized structural design of a geometrically complex high-rise structure and the optimal design of its architectural building shape. The second one focuses on the optimization and design of a perforated steel I-section beam, since such structural members are widely used nowadays in the vast majority of steel buildings and structures while they provide numerous advances. Conclusions are drawn regarding the potential benefits to the more widespread implementation of topology optimization within the civil/structural engineering industr

Designing by Geometry. Rankine's Theorems of Transformation of Structures.

William John Macquorn Rankine (1820-1872) was one of the main figures in establishing engineering science in the second half of the 19th. Century. His Manual of Applied Mechanics (1858) gathers most of his contributions to strength of materials and structural theory. A few additions are to be found in his Manual of Civil Engineering (1862). The book is based in his Lectures on Engineering delivered in the Glasgow University, and formed part of his intention of converting engineering science in a university degree (Channell 1982, Buchanan 1985). Both in plan and in content the book shows and enormous rigour and originality. It is difficult to read. As remarked by Timoshenko (1953, 198): "In his work Rankine prefers to treat each problem first in its most general form and only later does he consider various particular cases which may be of some practical interest. Rankine's adoption of this method of writing makes his books difficult to read, and they demand considerable concentration of the reader." Besides, Rankine does not repeat any demonstration or formula, and sometimes the reader must trace back the complete development through four or five previous paragraphs. The method is that of a mathematician. However, the Manual had 21 editions (the last in 1921) an exerted a considerable influence both in England and America. In this article we will concentrate only in one of the more originals contributions of Rankine in the field of structural theory, his Theorems of Transformation of Structures. These theorems have deserved no attention either to his contemporaries or to modern historians of structural theory. It appears that the only exception is Timoshenko (1953,198-200) who cited the general statement and described briefly its applications to arches. The present author has studied the application of the Theorems to masonry structures (Huerta and Aroca 1989; Huerta 1990, 2004, 2007). Rankine discovered the Theorems during the preparation of his Lectures for his Chair of Engineering in the University of Glasgow . He considered it very important, as he published it in a short note communicated to the Royal Society in 1856 (Rankine 1856). He included it, also, in his article "Mechanics (applied)" for the 8th edition of the Encyclopaedia Britannica (Rankine 1857). Eventually, the Theorems were incoroporated in the Manual of applied mechanics and applied to frames, cables, rib arches and masonry structures. The theorems were also included in his Manual of civil engineering (1862), generally in a shortened way, but with some additions

QoS oriented MapReduce Optimization for Hadoop Based BigData Application

International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc

Steelwork design guide using locally produced steel sections second edition

Aims principally at students who are following courses in steelwork design as well as at practicing professionals who are interested in the subject. The book consists of design calculations of building elements such as beams, columns, and connections, using locally produced steel sections. Step by step calculations in the design of these elements are presented here to assist civil engineering students and interested professionals alike. The design is based on BS 5950: Part1:1990 Structural use of steelwork in buildings using the dimensions and properties of hot-rolled steel sections produced locally by PERWAJA Steel Sdn. Bhd

Didactic strategies for comprehension and learning of structural concepts

p. 926-937In previous papers we have established the convenience of formulating educational strategies at the university level for both disciplines: Civil Engineering and Architecture, which involves academic topics of mutual interest by means of shared practices. As a particular matter of this approach, the application of physical experimental models is considered of special usefulness, in order to understand in better ways the performance of materials and structural systems. Several strategies of selection and development of such physical models will be discussed in this work, considering as a first step, the establishment of its correspondence with the different levels of structural complexity studied in curriculum plan: statics, strength of materials and structural design, among others. This task constitutes a part of the work program of the Laboratory of Structural Models, which is an academic project that develops and applies different didactic prototypes to structure courses in the Universidad Autónoma Metropolitana, campus Azcapotzalco, in Mexico City, project we have already presented in recent forums. Two different modes of application are implemented in classroom sessions and in structures workshop: the devices for functional demonstration of typical cases of structural work as well as the experimentation with student's own designs of destructible models where certain typologies are tested up to its failure limit. The first one allows teachers to explain adequately the theoretical principles and formulas (that usually are expressed on the blackboard) by means of didactic models identified in accordance to specific cases of the curriculum on variable level of complexity. This kind of practice allows the students of architecture and civil engineering to realize in better ways the possibilities of use and application of the different structural typologies. Such experimental models are part of more than fifty devices of the Laboratory's catalog. In the same sense, the possibility of observation of structural work of their own architectural designs, allows future professionals to achieve a better conception of the structural solutions that affect positively their designs. Based on specific predefined guides, the students develop their own architectural-structural projects and subject them to diverse loads, observing their behavior under the influence of variable stresses leading up the experiment to its last resistance. From both experiences a significant learning is obtained for the student's formation and training, who will be capable in his future professional work to use better tools of comprehension of the structural concepts applied to architecture as well as of increasing his conscience of the benefits and convenience of multidisciplinary work.Moreno, C.; Abad, A.; Gerdingh, JG.; Garcia M., C.; Gonzalez C., O. (2010). Didactic strategies for comprehension and learning of structural concepts. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/695

Performance-based engineering for multiple hazards: the role of structural reliability and risk assessment

Buildings, bridges and other civil infrastructure facilities are designed by current codes and standards using provisions that invariably are prescriptive in nature. While facilities so designed usually possess adequate levels of safety under design-basis events, other environmental or man-made events may cause them to suffer damage or loss of function, leading to economic losses, with uncertain impacts on the building occupants, owners and the community that they serve. The new paradigm of performance-based engineering enables structural engineers to achieve more reliable and informative prediction of civil infrastructure behavior and control of performance across a range of hazards. When supported by a risk-informed decision framework founded on structural reliability principles, performance-based engineering provides stakeholders with a structured framework for thinking about performance objectives, uncertainty, and how public safety and socio-economic well-being may be threatened by the failure of civil infrastructure to perform under a spectrum of hazards

Estimating deformations of laboratory structures subjected to loadings using images collected with phone cameras

A Fundamental civil engineering knowledge is the ability to understand, explain and calculate deformations of/in civil structures. New civil engineers acquire this knowledge at universities in material science, engineering mechanics and introduction to structural engineering modules. Structural deformations can be calculated when knowing material properties, geometry and boundary conditions of a structure and loads that are applied on/to it. Inverse engineering can be employed if deformations of a structure are known, but some other parameters are not known. Theoretical formulae are then tested using laboratory test beds, usually beams. Laboratory technicians are responsible for the acquisition of deformation measurements of laboratory tests. Their time is often limited and so is the number of available measurement collection devices such as dial gauges and strain gauges. If devices that do not log measured deformations are employed, information of structural deformations or response might be lost or readings might not be collected at required intervals. However, all laboratories do not offer luxury of sensors that are available at hand and technicians, which would have time to install sensors and collect data when needed, especially if this has to be done within a short period of notice. This paper introduces a low-cost vision-based system for deformation estimations of laboratory structures

Assessment of Factors Responsible for the Choice of Contractors’ Prequalification Criteria for Civil Engineering Project: Consultants’ Perspective

It is not uncommon, during contractor selection process, for prequalifier's decisions to be informed by certain parameters. In the light of this, the choice of the criteria to be eventually adopted depends on factors that play complimentary role when the contractor is to be selected. Therefore, this study assesses the factors that determine the choice of contractors' prequalification criteria for civil engineering project. The purpose is to bring the unrecognised factors into limelight by establishing the degree of their relevance on the choice of contractor's prequalification criteria as well as ascertaining their importance to meeting stakeholder's objectives. The objectives include identifying the factors which determine the choice of contractors' prequalification criteria for civil engineering project and assess the importance of the factors to meeting stakeholders' expectation. The study employ well-structured questionnaire distributed to various category of respondents comprising Civil/Structural Engineers, Quantity Surveyors and Architects engaging in civil engineering project. It adopts percentile, mean item score (MIS) and relative importance index (RII) in the analysis of the data derived from the retrieved questionnaire. Result indicates that, apart from Civil/Structural Engineers, employment into civil engineering organizations favours Quantity Surveyors than Architects. Construction of building is paramount among civil engineering organizations with little involvement in railway project. The choice of contractors' prequalification criteria for civil engineering project is dictated by a number of factors with project type emerging the most influential. Importance of the factors touches the client, consultants and contractor. It recommends that Quantity Surveyors should embrace continuous professional development. Factors influencing the choice of contractors' prequalification criteria must be duly considered before taking final decision on the criterion/criteria to adopt in choosing the contractor for civil engineering project prioritizing project type

Performance Assessment of Concrete Crack Repairing Materials using PZT Transducers

Department of Urban and Environmental Engineering (Urban Infrastructure Engineering)Concrete is a widely used material in construction of civil infrastructure engineerings such as dams, houses, bridges, and energy plants. Due to shrinkage, rapid dry of the concrete, and overload, cracks are usually generated on the concrete structures and can possibly cause durability-related issues and structural damages. Thus, the concrete crack is an important indicator of potential durability degradation and damage, and the crack should be monitored and repaired through regular maintenance. Indeed, identifying and repairing the concrete cracks using healing materials is important. While most research efforts to date have been devoted to investigation of crack locations and sizes and effective repair, few are evaluating the repairing performance. Therefore, to find an effective nondestructive evaluation (NDE) method for assessing the repairing performance of different healing materials is necessary. Meanwhile, the electro-mechanical impedance (EMI) employing the Piezoelectric Ceramic Lead Zirconate Titanate (PZT) is widely used in structural health monitoring (SHM) as an NDE method in the civil engineering field. The PZT-based EMI is usually applied to detect and locate structural damage in operation. This study used PZT EMI to extract the impedance, which was used as the damage indicator to evaluate the repairing performance of three different materials of the healing cement material from Intchem company, superabsorbent polymer (SAP), and epoxy. A comparison study on the different computation methods of damage index (the root-mean-square deviation (RMSD), the shift of resonance frequency (SRF) and the mean absolute percentage deviation (MAPD)) is also conducted. Results show that the increase of crack depth level and the completing process of repairing crack can be carried out by the change rates of the impedance (admittance) and the shifts of the resonance frequency of PZT sensor in the selected frequency range clearly. .ope