Practice Periodical on Structural Design and Construction

This paper discusses the development of structural design of concrete box culverts, which may be appropriate for the climate and soil conditions in the Sudan. The standard requirements in the Design Manual for Roads and Bridges (DMRB) were used in the formulation of the structural design of concrete box culverts and also a reference has been made to the American Association of State Highway and Transportation Officials (AASHTO) standard specifications for highway bridges. This formulation has been applied to many practical problems. The results obtained by using this formulation were comparable with commercially available software solutions, such as PROKON. A very good agreement has been achieved. This formulation deals with all types of culverts including single cell, twin cell, and multiple cellular.

This study examines whether a first-order, linear geometric finite-element static model analysis is capable of accurately predicting the deflection and rotation response of a curved steel I-girder bridge and curved steel I-girders. Girder deflections obtained during the erection of a horizontally-curved steel I-girder bridge and deflection and rotation data from curved-beam laboratory tests were used to determine if a linear geometric finite-element analysis could accurately predict their static behavior. Results indicate that the first-order, linear geometric finite-element model accurately predicts the deflection behavior of a horizontally-curved steel I-girder bridge and a curved steel I-girder beam tested under point loads. The results also indicate that the first-order, linear geometric finite-element model predicted the general rotation trends of the experimental beam accurately. However, the model overpredicted peak flange-tip displacements when compared with the experimental results.

Rotationally molded polyethylene water storage tanks have been produced since the 1950s when the technology became available for this manufacturing process. For circular tanks manufactured in this way, the traditional method of design has been based on hand calculations considering internal hydrostatic pressure from the stored liquid as the primary applied load. This study presents the results of the optimal structural design of 16 circular polyethylene water tanks of various sizes. Based on the results derived, optimal design recommendations for these tank structures are provided when both hydrostatic pressure and wind loads are applied.

A few innovative designs and construction measures are introduced to build a roller-compacted concrete (RCC) gravity dam with a height of 160 m (524.96 ft), whereas the design peak ground acceleration of the dam site is $0.3995g$. The grouting construction joints are designed between the plant and dam parts to enhance the earthquake-resistant ability of the dam. To improve the lateral stability of the dam, the depth of the construction joint is only $2/3$ of the dam thickness in each roller-compacted layer, and the joints are filled with nonwoven fabrics. This treatment causes the construction joints to be weakly connected induced joints, which are not only good for temperature stress release but also enhance the integrity of the dam. Steel bars are embedded in high-tensile stress zones to ensure dam safety. Some other aspects, such as layout of the stilling basin, spillway chute design, high-pressure consolidation grouting of dam foundation, the reinforcement of slumping mass on the left bank, and other engineering measures, are also described in this paper.

Underground utility tunnels present some unique constructional and operational considerations that require specific approaches to achieve optimal system performance and maintenance. From the construction point of view, perhaps the main issue is the avoidance of the accumulation of water in the surroundings of the structure. The design and construction of an adequate drainage system is important in avoiding added pressure on side walls and subslab pressure on the bottom concrete slab, as well as avoiding contact of water with the structure that could result in infiltrations that could impair the functionality of the construction and lead to ensuing and major repair costs. From the point of view of management and operation, some aspects of the overall design, such as coordinating different economic agents and ensuring the safety and integrity of the facility (from accidents as well as sabotage), require considerations that are not present in other typical civil engineering projects. This article relates these considerations to a specific case of an underground utility tunnel, or gallery, of approximately 7,885 m that was recently built for a new urban expansion area in the city of Pamplona, Spain.

The increasing shortage of available spaces in urban areas resulting from the construction and consolidation of certain facilities related to basic services (such as transport) mean that the provision of infrastructure is sometimes excessively complex in relation to its intended use. This article describes, in detail, the building of an underpass under railway tracks using a system of pushing a structure consisting of a ready-built reinforced concrete box using jacks. Implementing the system proved particularly delicate, given the constraint of maintaining normal rail traffic throughout the construction of the underpass. The primary responsibility was to design and effectively carry out a process that would adequately guarantee the safeguarding of the stability and maintenance of the track bed while the box was being pushed underneath, at what was an undeniably shallow depth (approximately 1 m). The developed system, although laborious, proved to be highly efficient, given that at no time during the course of the work did there arise any circumstances that might jeopardize either the safety of rail traffic or the physical integrity of the workers on site.