Practice Periodical on Structural Design and Construction

Construction impact and steady-state vibration sources such as pile driving, dynamic compaction, and other machinery generate ground and structural vibrations that may detrimentally affect diverse adjacent and remote structures, people, and sensitive devices. Vibration effects on structures depend on numerous factors. Vibration limits developed in the blasting industry are often used for evaluation of the construction vibration effects on structures. However, these vibration limits were derived only for specific combinations of blasting, soil conditions, and structures. Soil deformations and soil-structure interaction determine soil and structure responses to vibration excitation. Soil and structure vibration responses should be the basis for applied tolerable limits. Diverse tolerable limits are proposed for various soil and structure vibrations. In addition to vibration measurements, condition surveys should be performed for analysis of the causes of the existing damage to structures.

Design of pipe racks used for oil and gas applications is very challenging and requires reliable coordination between several engineering disciplines. Few guidelines are available in North American and European codes of practice for practitioners to effectively design pipe racks. In practice, there is currently no standard procedure to implement. Unfortunately, the design is performed in a random fashion, and the engineers may overlook critical aspects. The paper provides some industrial guidelines for practicing engineers and steel fabricators to design steel pipe racks. The author was involved in several megaprojects during the feasibility and detailed design phases and will present to readers some critical aspects for the design of pipe racks. Additionally, there is a focus on the design coordination required by engineering disciplines. The paper also describes modeling of the pipe rack design loads, modularization procedure, and the foundation system. Design recommendations are also outlined for practicing engineers to avoid excessive member sizing and optimize the structural utilization.

Numerous codes and standards specify means to calculate material-induced loads that are needed to design silos. The three most commonly used of such codes do not provide users with consistent information, and many common silo design conditions are not covered. A brief description of each code and its limitations is provided, and common design conditions not covered by any code are identified.

Despite the use of trenchless methods in sewer rehabilitation for over 40 years, a lack of knowledge on the performance of emerging technologies is still a critical need in the sewer infrastructure industry. This has led to aging water infrastructure research organizations to develop rehabilitation technology demonstration programs. The results from these programs are intended to enhance the industry’s awareness of available technologies and their capabilities. One specific scenario of interest is the rehabilitation of large-diameter sewer mains. This paper describes the demonstration of an innovative fiber-reinforced composite cured-in-place pipe technology used to rehabilitate 5,243 m (17,200 ft) of 2,400-mm (96-in.) RC pipe in Irving, Texas. This technology met the utility owner’s requirements and mechanical testing showed that the liner exceeded the minimum design requirements. A key take away from the project was the importance of proper planning. Careful attention is required to ensure proper and timely preparation in advance of the lining equipment setup, especially when a project has multiple installation shots (i.e., 19 total in this case). Another important consideration is the site access and layout. Several large pieces of equipment (e.g., resin tankers, cure control trailer, wetout tent, tractor trailer, etc.) are required and access is needed to move the resin tankers in and out during on-site liner wetout. These findings are valuable for water infrastructure system engineers who need alternate methods from the traditionally disruptive pipeline renewal methods.

Theodore Burr built several very important bridges of various designs across the Hudson and Mohawk Rivers; however, none was as large as his bridge across the Delaware River in Trenton, New Jersey. The overall length of the five-span bridge was 1,008 ft with a width of 36 ft ($1\hspace{0.17em}\mathrm{m}=3.28\hspace{0.17em}\text{ft}$). It was a unique bridge, with the deck suspended from arches and with partial covering. Construction started in 1804 and the structure opened as a toll bridge on January 30, 1806. With renovations and expansions, it served until 1875. The next bridge to cross the Delaware was Timothy Palmer’s bridge in Easton, Pennsylvania, which opened in late 1806.

Allowable bending fatigue stress is an important input for rail section design because of the nature of repeated loading on railways. The majority of rail failures have their origin in fatigue. In the American Railroad Engineering and Maintenance-of-Way Association (AREMA), there is only a fatigue test under the name of rolling load test for bonded joints; there are no fatigue tests for parent rail and welded joints. With respect to bonded joints, there is no known railroad or transit agency that uses plain bonded joints as an alternative to either flash butt weld (FBW) or alumino thermite weld (ATW) joints. A rail or weld should be able to resist at least 2 million stress cycle repetitions without developing any cracks. In this paper, allowable bending fatigue stress is formulated analytically with the nominal stress method (S-N). Marin’s six modification factors are applied to the laboratory-determined fatigue limit to account for surface conditions, size, load, temperature, reliability, and shape. Then, Goodman’s mean stress correction factor is applied to account for mean tensile stress in the rail. A brief literature review on the modification factors is included. The allowable bending fatigue stress is calculated and validated theoretically, then compared with the recommended AREMA value. Finally, the current AREMA formula and its recommended value for allowable bending fatigue stress are discussed.

This paper examines the impact of a natural phenomenon—the environment—on the evolution of colonial church architectural configuration and construction technology. It primarily examines the design and construction evolution of churches built during the seventeenth and eighteenth centuries in the northern coastal region of Peru. Though El Niño rains accomplished the destruction of a few churches, seismic activity, which the Spanish builders failed to consider initially, was the main natural phenomenon that drove the changes in the architectural configurations of these churches. This study emphasizes the fact that architects and engineers must always consider the physical environment of their projects; this is especially important when designer and builders accept projects beyond their normal areas of professional practice.