Journal of Performance of Constructed Facilities

In November of 1990, approximately 850 m (2,800 ft) of the 2020 m (6,620 ft) long Lacey V. Murrow Bridge (LVMB), a 50-year-old floating concrete bridge over Lake Washington near Seattle, sank after a major storm. The bridge had been closed for renovations for several months when it sank; there were many structural changes and interim conditions which affected the performance of the bridge. The investigation described herein identifies the most probable causes of the failure. The primary cause of the sinking of the LVMB was water that accumulated in the bridge during renovation. Hydrodemolition, rain, and wave splash water entered through construction openings and severed roadway drains. The cause of the failure was unrelated to strength reductions caused by the openings, and the age and condition of the bridge were of minor significance.

This paper presents results of a study conducted on several residential structures to determine the design and construction deficiencies that contributed significantly to their failure. The failures in masonry construction can mainly be attributed to lack of anchorage because the wall reinforcing was either missing or not hooked to the tie beam. Some masonry-wall failures were also caused by the tie beam bending about its minor axis when subjected to lateral loading. The failures in framed construction can mainly be attributed to deficient design and construction practices. Wood end gables were a typical feature in houses in South Florida that failed due to lack of proper bracing. Loss of roof sheathing was also common due to inadequate nailing. The breach of the exterior building envelope by the loss of roof sheathing and broken windows/doors led to extensive interior damage in most houses.

Over the last 30 yr, Eastern Canada has experienced several droughts during which extensive settlement problems developed in lightweight buildings founded on the Champlain Sea clays. These clays are known for their open structure, which collapses when the moisture content is decreased and does not return to its initial state if water is added to the soil. This type of situation occurs during droughts in which the lack of rainfall causes the desiccation of clays. If trees are located in close proximity to buildings founded on shallow footings the problem is exacerbated, since the roots can grow beneath the foundations and extract moisture during droughts. This will cause the clays to shrink and the structures to settle. The goal in dealing with these clays is to try to maintain a constant soil moisture. The elimination of planter areas around the perimeter of the buildings can help reduce moisture changes. This paper presents the results of a field monitoring program, on the effectiveness of different irrigation systems, in maintaining a constant soil moisture and in reducing building settlements in the clay deposits of Montreal Island.

This paper describes the reactivation of an ancient landslide during the construction of a fill buttress. Even though precautions were taken during construction of the buttress, such as excavating it in 30-m-long (100-ft-long) segments, the ancient landslide nevertheless was reactivated. The reactivated landslide moved laterally about 5–8 cm (2–3 in.), which resulted in significant damage, such as cracking to building foundations, walls, and ceilings, as well as distortion of door frames and windows. An interesting observation was that the ancient landslide, once activated, did not stop immediately after the buttress had been backfilled. The lateral movement continued for about 10 months, at a decreasing rate of movement. This movement was probably due to the slow closure of the ground cracks as well as the deformation of the landslide into the buttress. This case history illustrates the disadvantage of using a buttress to stabilize an ancient landslide, especially when the excavation is below the rupture surface.

Nondestructive testing (NDT) for the evaluation of deep foundations has been practiced for more than a quarter of a century, usually on new construction projects. It is not always realized that the performance evaluation of older, deep foundations under existing structures can be enhanced by nondestructive testing. The NDT techniques currently available for this objective are described and critically reviewed in this paper. Case histories illustrating the use of different methods to inspect existing piles, drilled shafts, and caissons are presented. Most of these NDT methods are applied in Europe and East Asia, and the present limited use of small-strain nondestructive testing in the North American deep foundation industry is discussed. It is concluded that the methods described in this paper could be usefully employed more often; their limited use is mainly a result of unfamiliarity with the tests and a lack of awareness of their potential by the general engineering community.

An innovative and inexpensive slope-stabilization scheme is presented that uses old rubber tires and woven geotextile to arrest the deterioration of a hill slope adjacent to a 100 m (328 ft) high microwave-transmission tower on the Indonesian island of Batam. Woven geofabric with a warp and a weft tensile strength of 80 kN/m (5.5 kips/ft) was used to resist the lateral earth pressure of the up to 2.15 m (7 ft) high wall. The internal stability and the sliding resistance, as well as the bearing capacity were checked. Rubber tires that were filled with granite aggregate and quarry waste were used to protect the fabric against direct sunlight and vandalism. Unskilled labor was used for the construction of the wall and of the fill. The total cost was less than 40% of the estimated cost of a conventional retaining wall. The paper discusses the design and the construction of the wall, as well as the costs.