Journal of Performance of Constructed Facilities

This research effort focuses on the evaluation of existing design standards for cold-formed steel stud walls and the development of retrofit wall systems. Full-scale wall systems are tested under uniform static pressure using a vacuum chamber. The resistance functions obtained are used to model the dynamic behavior of the walls and to predict performance under blast conditions. This paper focuses on defining the static resistance of nonload-bearing steel stud walls with slip track connections and their performance under external explosions. Simple modifications to existing design practice have significantly improved the blast performance of the steel stud walls. Maximum blast resistance is achieved by using steel angles connected to the studs and anchored to the floor and ceiling. The static and dynamic performances of five full-scale steel stud wall systems are presented in this paper.

The seismic performance of reinforced concrete frames designed for gravity loads is evaluated experimentally using a shake table. Two 1:3 scale models of one-bay, three-storied space frames, one without infill and the other with a brick masonry infill in the first and second floors, are tested under excitation equivalent to the spectrum given in IS 1893-2002. From the measured response of the models during excitation, the shear force, interstory drift, and stiffness are evaluated. The effect of masonry infill on the seismic performance of reinforced concrete frames is also investigated. Then, the frames are tested to failure. Severe damage is observed in the columns in the ground floor. The damaged columns are strengthened by a reinforced concrete jacket. The frames are again tested under the same earthquake excitations. The test results showed that the retrofitted frames could sustain low to medium seismic forces due to a significant increase in strength and stiffness.

Construction inspection can take place only during the construction phase of a project. This imposes limitations on what the building inspector can detect, and thus there is often a gap between perceived construction quality and the defects the occupants suffer from later. This research paper looks into the differences among the defects that occurred during construction and 2 to 6 years after initial occupancy and finds that the defects at both periods were very different. Defects found during the occupancy stage are commonly known as latent defects, most of which were rarely found during the construction stage and are thus rarely accounted for by the designers and building developers. This paper confirms the need to look at defects in another way and to establish more effective methods to reduce latent defects.

The runway of an international airport on the west coast of India was struck by lightning three times in succession at the rate of once every year. On two occasions the runway proper was damaged, and on the third the road around the periphery of the runway was cracked and a coconut tree burnt. A part of the runway was built on an embankment of a height varying from $30\text{to}40\mathrm{m}$ , and the periphery road was close to the embankment. The strategic importance of the runway and the fact that the vegetation around the embankment provided a sacrificial protection led to making a study of the cause of the problem of lightning strike and working out a solution. That solution consisted of providing suitable lightning protection conforming to international and national standards for the runway, incidentally providing natural lightning protection using tall trees with good biomass for the root system. The problems confronting the airport authorities and the solution to those problems are presented in this paper.

Sand drift and sand dune movements are typical logistic problems facing civilian and industrial cities in arid and semiarid countries like Saudi Arabia. Some of these countries are considered active when it comes to sand drift and sand dune movement, due to the high annual sand drift rate. Urban cities have extensive facilities in the middle of these active areas that require good protection and innovative solutions to this problem. This paper briefly reviews sand movement control measures and highlights sand drift fence design guidelines for the first time.

This paper presents a case study detailing a riverbank dike damaged by pile driving in very soft clay in Shanghai, P. R. China. Driven piles were designed to support the existing dike to be raised to a higher elevation. The subsoil mainly consisted of very soft clay with its natural moisture content greater than its liquid limit. This paper describes the phenomena of dike movement and crack development during pile driving based on field observations and instrumentation data. Cone penetration tests and vane shear tests were conducted after pile driving to investigate the slip surfaces. Degradation of soil strength was identified as the main cause for the failure of this dike. Slope stability analysis was conducted to back-calculate the degraded undrained shear strength of the clay. The results indicate that the soil strength in the disturbed area due to pile driving approached the level of its remolded strength.

Many earth structures, including foundations, retaining walls, and road embankments, exhibit signs of distress, such as excessive vertical or lateral movements and cracking. Rotation or tilting and cracking of the structural components in retaining walls are quite common and constitute the majority of cases of concern in built-up areas. This paper describes a general iterative methodology for the diagnosis of existing civil infrastructure, with emphasis on geotechnical problems. The term diagnosis, as used in this paper, refers to the process of determining a set of technical explanations for the occurrence of the observed defects. Using probability theory, the investigating engineer is in a better position to make informed decisions rather than simply relying on experience and intuition. Engineering decisions include the correctness of a given hypothesis; whether further investigations are necessary or a terminal decision can be made; and whether appropriate corrective action can be undertaken. A case study is used to demonstrate the application of the methodology.

This case history presents an application of dynamic compaction in placement of a road embankment with a height of 41 m on the Yuncheng-Sanmenxia Expressway, Shanxi Province, China. The monitoring results during the compaction and the long period after compaction are analyzed and compared with those from compaction by rolling. It is obvious that dynamic compaction has such advantages as a high degree of compaction, a wide suitable range of placement water content (7–19%), and quick construction (over 4 m lift thickness) and can be applied in many high-fill engineering projects. In addition, application of a fabric-enclosed sand drain for treatment of an overwet soft foundation for a road embankment is also introduced.

This paper focuses on the cause, possible solutions, and future prevention of pavement heave at a new construction project. We speculated that heaving on the east side of the project was caused by a reaction between the lime stabilizer and minerals in the soil. Because of a difference in soil chemistry, the west side of the project (which was still under construction) did not show evidence of heaving. A forensic investigation was initiated to test our hypothesis. The findings of the investigation concluded that the cause of the heaving on the east side of the road was related to the formation of the expansive mineral, ettringite. Ettringite formed due to the reaction of the lime stabilizer with seams of high sulfate soil on the east side. Laboratory testing did not find any effective stabilizer for the high-sulfate soils on the east side. Therefore, reconstruction would involve removing and replacing the treated layer with a select material that has less than $\mathrm{2,000}\mathrm{ppm}$ sulfates. Test results indicate that there was no threat of sulfate heave on the west side. District personnel had performed the field conductivity tests to evaluate and monitor the concentration of the sulfate content on the remaining project. The treatment of $3\%∕72\text{-}\mathrm{h}$ mellowing period/3% lime treatment was employed on the west side. The whole project has been completed for $1\text{year}$ and no heave has been observed.

The Illinois Department of Transportation (IDOT) initiated a failure investigation to determine the distress mechanisms causing premature longitudinal cracking on continuously reinforced concrete pavements (CRCP) on several Illinois interstates. The longitudinal cracking approximately followed the embedded reinforcement steel and occurred in both the driving and passing lanes. In this paper, the results from field visual surveys, coring, and petrographic analyses are reported along with a review of archival construction and material records of the distressed CRCP sections. A laboratory forensic study was also performed on several field extracted slabs. The results of the field and laboratory investigation show the cracking was not initiated by steel corrosion, deleterious reactions in the concrete materials, or an inadequate structural design. Rather, the cracking is related to settlement of the steel bars in the concrete. Settlement cracking is conventionally thought to occur only in concrete slabs and decks with plastic (high slump) concrete and small values of bar cover depth, while the studied CRCP sections have large values of cover depth and were cast with stiff (low slump) concrete. The settlement was likely caused by the relative settlement of heavy steel bars ( $22\mathrm{mm}$ diameter) within the lower density concrete during the original CRCP construction. The technique of placing the steel bars in the fresh concrete (called tube-feeding) further contributed to the development of this distress, and this practice is no longer employed by IDOT.

Performance assessment in urban water infrastructures is an increasingly important field of knowledge. Performance has traditionally been expressed in a variety of ways relating mostly to local design practice, with hardly any consensus on how it should be measured or compared. The efficient technical management of these systems deserves a specific approach, suited to the methodologies regularly employed while planning, designing, constructing, operating, and maintaining the systems. At the engineering level, decisions are based on operational, physical, and resources data and on analyses deploying simulation models, geographic information systems, or other information systems. However, such tools tend to produce vast amounts of insufficiently aggregated or performance-oriented information. This paper presents a performance assessment system that is based on the decisional concept of utility functions and designed as a technical analysis tool with the purpose of shifting the focus of technical management of urban drainage systems to a performance-oriented view.

Sewage outfalls are common inclusions in the infrastructure of coastal cities and towns. Near-ocean industries may also make use of such pipes. Keeping such a conduit operating properly is by no means a trivial matter, and this paper is the first of two dealing with this complex topic. Herein, the various failure and impairment mechanisms are summarized, and the need for careful underwater inspection is stressed. Examples are given of inspection, maintenance, and repair operations for various municipal facilities. The paper closes with presentation of two improvement procedures, pigging and sliplining.

This paper, the second in a series, outlines the various methods that can be used to immobilize and protect an exposed outfall pipe that appears vulnerable to destabilizing agents such as waves, ice, logs, or fishing trawls. Measures covered include the placing of quarry rock or articulated concrete block mats, the driving of piles, and the installation of stapling arrangements. Case studies cover various specific outfalls where particular stabilization measures were employed. Environmental considerations are included.