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Showing papers in "Journal of Computing in Civil Engineering in 1987"


Journal ArticleDOI
TL;DR: The application of a genetic algorithm to the steady state optimization of a serial liquid pipeline is considered and computer results show surprising speed as near-optimal results are obtained after examining a small fraction of the search space.
Abstract: The application of a genetic algorithm to the steady state optimization of a serial liquid pipeline is considered. Genetic algorithms are search procedures based upon the mechanics of natural genet...

264 citations


Journal ArticleDOI
TL;DR: Among other concerns, construction planning involves the choice of construction technology, the definition of work tasks, estimation of required resources and durations, the estimation of costs, and the selection of costs.
Abstract: Among other concerns, construction planning involves the choice of construction technology, the definition of work tasks, the estimation of required resources and durations, the estimation of costs...

98 citations


Journal ArticleDOI
TL;DR: This paper considers the role the computer can have in less‐formalized phases of the structural design process, particularly during preliminary design, and presents HI‐RISE, an expert system that addresses the decisions made in generating a structural grid for a building.
Abstract: This paper considers the role the computer can have in lessformalized phases of the structural design process, particularly during preliminary design. Since preliminary design is based largely on t...

61 citations


Journal ArticleDOI
TL;DR: In this article, 24 previously unpublished expert systems were developed for applications in environmental engineering, summarized in three principal categories: hazardous waste makings, hazardous waste management, and hazardous waste minimization.
Abstract: Twentyfour previously unpublished expert systems are being developed for applications in environmental engineering. These new systems are summarized in three principal categories: hazardous waste m...

29 citations


Journal ArticleDOI
TL;DR: A methodology in which an expert system shell (INSIGHT 2+) is used to evaluate and display information on drought management planning and a linear programming model is usedto generate optimal operating policies as a function of numerous past drought experiences is presented.
Abstract: Expert systems have been proposed for a wide range of civil engineering applications. They have been applied most successfully in situations governed by simple rules. Many civil engineering decisions, however, must be made in environments in which simple rules are not possible, but rather large amounts of data must be analyzed and evaluated. This paper presents a methodology in which an expert system shell (INSIGHT 2+) is used to evaluate and display information on drought management planning. A linear programming model is used to generate optimal operating policies as a function of numerous past drought experiences. These policies are incorporated into an expert system where the user is required to identify the degree to which the current drought situation is similar to past events. The expert system then aids the user in developing appropriate management policies based on time of year, descriptions of drought intensity, and other system characteristics.

29 citations


Journal ArticleDOI
TL;DR: In contrast to formal shape optimization procedures that are computationally expensive and may produce non-practical designs, this synergic man-machine approach is an effective method for practical layout optimization of trusses.
Abstract: A method is presented for performing practical layout optimization of trusses subjected to arbitrary multiple-loading conditions using interactive computer graphics. Design constraints are allowable tensile and compressive stresses based on the American Institute of Steel Construction specification as well as user-specified displacement constraints and lower and upper bounds on design variables. The layout optimization is based on changing certain key dimensions of the truss and performing optimization for each layout by taking advantage of the interactive environment of computers with graphic facilities. In contrast to formal shape optimization procedures that are computationally expensive and may produce non-practical designs, this synergic man-machine approach is an effective method for practical layout optimization of trusses.

23 citations


Journal ArticleDOI
TL;DR: Three categories of tools are examined: shells, programming environments, and rule-induction software, which use case examples to derive rules and have potential value as aids in knowledge aquisition.
Abstract: Although some expert systems utilize artificial intelligence languages such as LISP and PROLOG, many rely on commercially available expert systems development tools. Three categories of tools are e...

19 citations


Journal ArticleDOI
TL;DR: The authors advance several ideas as to why this application domain is receiving so much attention and why the construction industry will benefit from these developments.
Abstract: Construction planning, engineering, management and maintenance are receiving increasing attention as possible application domains for knolwedgebased expert systems. Although oportunities for this n...

18 citations


Journal ArticleDOI
TL;DR: The EIDOCC (Expert Interactive Design of Concrete Columns) program uses the accumulated experience and knowledge of experts in the field of concrete column design to account for the issues involved in the design in order to make an optimal design proposal for given loadings.
Abstract: A new computerbased approach to the problem of design of reinforced concrete columns that may be subjected to biaxial bending is presented. Previous approaches to the design of concrete columns inc...

16 citations


Journal ArticleDOI
TL;DR: Using the kinematic approach with automatic generation of independent mechanisms, an efficient procedure and an interactive microcomputer BASIC program have been developed for optimal plastic design of low-rise frames of general configuration.
Abstract: Using the kinematic approach with automatic generation of independent mechanisms, an efficient procedure and an interactive microcomputer BASIC program have been developed for optimal plastic design of low‐rise frames of general configuration. This procedure has been compared with a previous algorithm for optimal plastic design of frames based on the static approach without generating the independent mechanisms. It is concluded that the kinematic approach with automatic generation of mechanisms is more efficient than the static approach without generating the mechanisms. In order to display/plot the failure mechanism by microcomputer, an efficient scheme has been developed for calculating the displacements of the joints of the failure mechanism called the “tree” method. In addition to the failure mechanism, the interactive microcomputer program can also display/plot the frame configuration including the loading, and the bending moment diagram. Four examples are presented. This research demonstrates the ef...

16 citations


Journal ArticleDOI
TL;DR: In this paper, an analytical computer study on the lateral behavior of unbraced framed structures having linearly tapered beam and column elements is presented, and the structural benefits and disadvantages of tapered members are compared with those of prismatic ones.
Abstract: An analytical computer study on the lateral behavior of unbraced framed structures having linearly tapered beam and column elements is presented. Because of their structural efficiency, particularly the high stiffness to mass ratio, tapered elements are desirable in seismic and wind design. The 6‐DOF stiffness matrix as well as the equivalent nodal loads for a linearly varying‐depth rectangular beam element are presented in an explicit form. The effects of taper on the lateral stiffness, strength, and dynamics of beams and frames are discussed. In addition, the structural benefits and disadvantages of tapered members are compared with those of prismatic ones.

Journal ArticleDOI
TL;DR: A review of the known expert systems applied to structural engineering is presented and a brief summary discusses the application and the implementation details of each system.
Abstract: In this paper, a review of the known expert systems applied to structural engineering is presented. The paper is organized into three principal sections: (1) commercial expert systems; (2) operational prototypical expert systems; and (3) demonstrational prototypes. For each system discussed, a brief summary discusses the application and the implementation details.

Journal ArticleDOI
TL;DR: It is the professional responsibility of the engineer to use the microcomputer as a powerful design aid only, not allowing his judgment to be sacrificed, and this ethical use centers around the following recommendations.
Abstract: The decreasing cost of the microcomputer has made its increasing capability available to civil engineering firms of all sizes and specialties. This availability, coupled with the fast growing libra...

Journal ArticleDOI
TL;DR: PILE, an expert system designed to assist users in selecting the appropriate type of pile foundation, is presented, a forward‐chaining system written in LISP that includes explanation capabilities, handles uncertainty, and resolves conflicts in data memory.
Abstract: Geotechnical engineering is a field where experiential knowledge has no substitute. Making experts' knowledge explicit, and documenting and transferring it can have a great impact on the state of p...

Journal ArticleDOI
TL;DR: In this article, a solution procedure using boundary element method is presented for seepage analysis of earth dams involving drawdown of the water level in the reservoir, and applicability of the boundary element meth...
Abstract: A solution procedure using boundary element method is presented for seepage analysis of earth dams involving drawdown of the water level in the reservoir. Applicability of the boundary element meth...

Journal ArticleDOI
TL;DR: In this article, the authors stress the advantage of using a shell system, in this case LOTUS 123, to perform storm drain designs, using analytical, algebraic relationships derived from linear diffusive wave theory and provide reasonably accurate designs at a very modest computational effort.
Abstract: The ability to accurately route flows through storm drain networks relies not only on the skill of the engineer, but also on the resources at his disposal. The purpose of this paper is to stress the advantage of using a shell system, in this case LOTUS 123, to perform storm drain designs. Pipe segments are conceptualized as storage elements, distributed or concentrated. The proposed analytical method uses analytical, algebraic relationships derived from linear diffusive wave theory and provides reasonably accurate designs at a very modest computational effort. This procedure is applicable to desktop calculations, but the utilization of the LOTUS environment provides the greater ease and efficiency necessary for routine use.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the effect of target size, shape, and its relative orientation with respect to the search pattern on the probability of intersection for each of the aforementioned search patterns.
Abstract: Results of an investigation which is aimed at improving search patterns used in subsurface exploration are presented. Expressions are developed for probability of detection of elliptical targets from various continuous line searches such as parallel lines, square, rhombus, rectangle, and parallelogram. It was assumed that the intersection of the target by search lines provides the condition for detection. Probabilities were calculated to study the effect of target size, shape, and its relative orientation with respect to the search pattern on the probability of intersection for each of the aforementioned search patterns. From this study it was possible to find the relative orientations which provide the maximum probability of intersection for different target sizes and shapes with different patterns. These calculated probabilities were also used to select the optimum search pattern to be used when exploring for elliptical shaped targets. The parallelogram shape was found to be the best pattern for detecti...

Journal ArticleDOI
TL;DR: An effort to develop a graphics capability to support an established simulation package called CYCLONE is reported herein, developed using AUTOCAD, which generates the required computer input for CYCLone.
Abstract: A goal of many computer simulation systems is the onscreen generation of the model being simulated. A recent effort to develop a graphics capability to support an established simulation package cal...

Journal ArticleDOI
TL;DR: In this paper, an electrical technique is described that monitors the chemical and physical changes occurring within cement paste, which can then be used to log the changes in electrical response of cement paste with time.
Abstract: An electrical technique is described that monitors the chemical and physical changes occurring within cement paste. The present research program has concentrated on the initial 24 hrs after gaging with water and investigates the influence of retarders, accelerators, and cements of different type on electrical response. The principal aim of this paper, however, is to describe the design and development of a microcomputer controlled data acquisition system, which can then be used to log the changes in electrical response of cement paste with time. The system described, which is an advancement on earlier techniques, highlights the application and use of microcomputers in the laboratory for instrument control.

Journal ArticleDOI
TL;DR: In this paper, a multiobjective personnel management model was developed to aid engineering managers in making seasonal job reassignments where the problem is to assign up to 150 workers to up to 50 jobs sites.
Abstract: A multiobjective personnel management model was developed to aid engineering managers in making seasonal job reassignments where the problem is to assign up to 150 workers to up to 50 jobsites. The model may be used to find efficient and equitable decision strategies within the constraints of known jobsite demand and limited resources. Rapid prototyping techniques were used to develop and test the model on a minicomputer system. The success of this prototype led to the subsequent implementation of the model using microcomputer technology. Program size was the major problem encountered in transferring the model from one computer system to the other. As a transportation model with one additional constraint, the nature of the formulation was exploited to overcome microcomputer storage limitations. Details of this redesign process and other strategies used to reduce the prototype size are presented together with a discussion of model performance.

Journal ArticleDOI
TL;DR: In this article, several methods of prediction are reviewed, with emphasis on the cone penetration test, and each method is based on a cone-penal penetration test and each one is evaluated with respect to the cone diameter.
Abstract: Prediction of the settlement of soil beneath a foundation is a very important part of foundation design. Several methods of prediction are reviewed, with emphasis on the cone penetration test. Each...

Journal ArticleDOI
TL;DR: The implementation on a personal computer of three-dimensional terrain modeling based on B-splines is described, which allows a large volume of survey data to be condensed to a significantly smaller number of parameters, which are then stored.
Abstract: The implementation on a personal computer of three-dimensional terrain modeling based on B-splines is described. Such models are useful for initial route location studies in highway planning and design. The model described makes use of B-spline-type surfaces defined on curved knot lines, which allows a large volume of survey data to be condensed to a significantly smaller number of parameters, which are then stored. These parameters may be used at a later time for the extraction of cross-sectional information or the reconstruction of three-dimensional images. This significant data reduction makes the modeling suitable for implementation on a personal computer because of reduced storage requirements and processing time. Timing for some examples is included.

Journal ArticleDOI
TL;DR: PC PUMPING as discussed by the authors is a computer program based on finite element methods that can accommodate both constant and variable material properties, several distinct aquifers, arbitrary histories of pumping and recovery, leaky aquifer, wellbore storage effects, skin effects, and the presence of planar and circumferential boundaries.
Abstract: Hydrogeologic parameters can be estimated from the observed recovery of pressure during pumping tests in deep strata, but the computations are tedious and may be limited by the availability of analytical solutions. PC PUMPING is a computer program, based on finite element methods, that can accommodate both constant and variable material properties, several distinct aquifers, arbitrary histories of pumping and recovery, leaky aquifers, wellbore storage effects, skin effects, and the presence of planar and circumferential boundaries. The program runs on a microcomputer. Solutions are obtained by iterative matching of modeled to actual pressure recovery curves. A menu‐driven system of input and direct graphical output to either CRT screen or pen plotter have greatly reduced the time required to analyze the results of pumping tests, and several hydrogeologists who have had little previous experience with computers are now using the system. The paper also discusses several issues of development and documentation.