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The tests were performed on 2.44 m by 2.44 m light-frame wall segments, having oriented strand-board sheathing nailed to sawn lumber framing, to determine their structural response to in-plane and out-of-plane forces applied separately or in combination. There was no evidence that simultaneous application of in-plane and out-of-plane forces negatively affects the strength of walls. However, it was found that interaction of different in-plane force components can substantially reduce strength capabilities of walls relative to when only one in-plane force component exists. Applying both in-plane tension and racking force in the ratio of 1:1 reduced the capacities of walls by 25 to 40%, with how lumber studs are connected to lumber base plates strongly influencing the absolute capacity of any wall. DOI: 10.1061/(ASCE)ST.1943-541X.0000170 CE Database subject headings: Bending; Combined loads; Frames; Wood; Nails; Shear walls; Uplifting; Structural behavior. Author keywords: Bending; Combined loads; Light-frame; Lumber; Nails; OSB; Racking; Shear-wall; Uplift; Walls; Wood.

The seismic resistance of full-scale superassemblage of precast hollow core wall units is investigated. The superassemblage consists of six prestressed concrete 1.2 m wide hollow core units. Two load-bearing of the units are tied to the foundation via unbonded vertical tendons while the other four units primarily act as 'nonstructural' cladding. The longitudinal unbonded prestressing tendons consist of regular thread-bars with an in-series portion of those bars possessing a reduced diameter to act as 'fuses.' The multipanel wall system is tested under several different conditions: in-plane quasi-static reverse cyclic loading with different sizes of fuse bars and with and without rubber block spacers and sealant between units. No structural damage occurs up to the experimental [+ or -] 4% drift limit and only minor nonstructural distress is observed at 3% drift. The overall good performance of the multipanel wall system well satisfies the requirements of an emerging seismic damage avoidance design philosophy. DOI: 10.1061/(ASCE)ST.1943-541X.0000183 CE Database subject headings: Damage; Structural design; Prestressing; Tendons; Cladding; Precasting; Walls; Seismic effects. Author keywords: Fuse bars; Damage avoidance design; Unbonded prestressing tendons; Nonstructural cladding; Multipanel precast hollow core wall.

This paper focuses on the design and performance of a very tall mechanically stabilized earth (MSE) wall. Expansion of Seattle-Tacoma International Airport called for the construction of a third runway west of the two existing runways. A significant volume of compacted earth fill was required to raise the grade as much as 50 m to meet the level of the existing airfield. Nominal 2H: 1V fill slopes were used where possible, but MSE retaining walls were used where fill slopes would have encroached into existing wetlands. Consequently a four-tier 46-m-tall MSE wall was constructed along a portion of the western edge of the embankment. Performance monitoring included strain gauge-instrumented reinforcing strips, inclinometer installations with sondex settlement rings, optical survey of the wall facing for vertical and lateral movements, and piezometers. This paper describes wall design issues, aspects associated with the instrumentation of the wall, and the observed performance. Monitoring indicates satisfactory performance of the MSE wall and compares reasonably well with predicted performance. DOI: 10.1061/(ASCE)GT.1943-5606.0000294 CE Database subject headings: Soil stabilization: Retaining walls; Performance characteristics; Instrumentation; Design; Displacement; Washington; Airport and airfield runways. Author keywords: Soil stabilization; Retaining walls; Performance; Instrumentation; Design; Displacement.

Slurry trench cutoff walls, constructed using self-hardening slag-cement-bentonite (Slag-CB), are the most common form of in-ground vertical contaminant barrier in the U.K., Europe, and Japan, and are increasingly being used in the United States. This paper presents a case study of the hydraulic conductivity evaluation of an 11-year-old Slag-CB wall material at a sulfate-contaminated site, using different in situ techniques and laboratory tests. The laboratory results suggest that the hydraulic conductivity of the samples, which vary in age from 4 weeks to 11 years, decreases with time for the first 3 years but then remains constant. The results indicate that the long-term performance of these containment walls is influenced by various parameters such as aging, the type/duration of contaminant exposure, mixing of surrounding soil during construction, and wall depth. Piezocone tests, packer tests, and self-boring permeameter tests were carried out in the field to determine the suitability of different in situ techniques and compare with the laboratory results. The hydraulic conductivity is affected by the type of in situ technique used and the geometric scale of the test section. DOI: 10.1061/(ASCE)GT. 1943-5606.0000248 CE Database subject headings: Bentonite; Cement; Containment; Groundwater pollution; Heterogeneity; Hydraulic conductivity; In situ tests; Slurry walls. Author keywords: Bentonite; Cements; Containment; Groundwater pollution; Heterogeneity; Hydraulic conductivity; In situ tests; Slurry walls.

This paper presents the results of four full-scale impact tests against barriers placed on top of an instrumented mechanically stabilized earth (MSE) wall. The impact was created by a head-on collision of a 2,268-kg bogie going at about 32.2 km/h. The barriers were New Jersey and vertical wall barriers with a 1.37-m-wide moment slab in 9.14-m-long sections. The wall was 1.52 m high with one panel and two layers of reinforcement. The reinforcement was 2.44-m-long strips, 4.88-m-long strips, and 2.44-m-long bar mats. The backfill was crushed rock. The instrumentation consisted of accelerometers, strain gauges, contact switch, displacement targets, string lines, and high-speed cameras. The test was designed to represent a commonly used installation in current practice including an impact load on the barrier at least equal to 240 kN. Most of the barriers sustained significant damage but overall the behavior of the wall was satisfactory since the displacements of the panels were minimal (less than 25 mm) and the panel damage was acceptable except possibly in the case of the 4.88-m-long strips. The loads measured in the reinforcement indicate that the reinforcement was brought to its ultimate capacity for the duration of the impact but since the impact duration was so short and since the displacements of the panels were within tolerable limits of 25 mm, this is considered acceptable. The use of the longer strips (4.88-m-long strips) leads to slightly smaller panel displacements and higher panel stresses as evidenced by a bending crack in the panel. The 2.44-m-long strips permitted more displacement of the wall panels, but the magnitude of the displacement was considered to be tolerable. The measured maximum dynamic loads in the strips were found to be 3-5 times higher than the calculated maximum static loads by AASHTO guidelines. DOI: 10.1061/(ASCE)GT.1943-5606.0000232 CE Database subject headings: Impact tests; Barriers; Highway and road structures; Pullout; Reinforcement; Walls. Author keywords: Impact text; Traffic barrier; Pullout; Reinforcement; Mechanically stabilized earthwalls.

With an inclinometer casing mounted on a sheet pile wall in peat bogs, sheet pile wall deflections were measured during a trial deep dynamic compaction (DDC) test. Analyses of the trial testing data indicated that sheet pie wall deflections were significantly affected by the tamping distance, X, (horizontal distance between tamping points and sheet pile walls). The DDC-induced wall deflections can be simulated by an exponential relationship related to X. The trial testing results were verified by the finite-element (FE) simulation. The FE analyses indicated that sheet pile wall deflections were linearly proportional to the impact energy per blow, [E.sub.i]. The analyses of surveyed data showed that sheet pile wall deflections due to DDC were also related to the ratio of the wall penetration depth in the underlying sands, [d.sub.s], to the wall height, L. Based on these findings, a semiempirical approach, incorporating the key factors that govern the sheet pile wall deflections during DDC, was developed. The estimated wall deflections using this developed method were in reasonable agreement with the field measurements. DOI: 10.1061/(ASCE)CF.1943-5509.0000059 CE Database subject headings: Deflection; Sheet piles; Walls; Empirical equations. Author keywords: Deflection; Sheet piles; Peat; DDC; Semiempirical.

Old residential buildings, such as those built before 1960, were commonly supported on cripple walls, which are walls constructed of short wooden studs between the foundation and first floor framing. For most of these old buildings, the inertial force developed by the horizontal earthquake ground motion must be resisted entirely by the cripple wall and wall-to-foundation connection. Past earthquakes in California have shown that unbraced cripple walls are particularly vulnerable due to insufficient lateral resistance, even for a moderate level of ground shaking. This paper summarizes the results of a test program conducted on level and stepped cripple walls. Specimens with details representative of current construction and retrofit were tested using displacement histories recommended for ordinary and near-fault ground motions. Key parameters of the test program included the height and slope of the cripple wall, gravity load level, stucco finish, loading history, and framing details for stepped cripple walls. Results from the test program are compared with current design values. DOI: 10.1061/(ASCE)0733-9445(2003)129:5(567) CE Database subject headings: Walls; Buildings, residential; Seismic response; California.

Eight shear wall specimens sheathed with 11 mm structural oriented strand board panels were assembled with overdriven sheathing nails and tested using a pseudo-dynamic procedure. Specimens used 38x89 mm Douglas Fir-Larch framing members and 8d cooler, gun-driven sheathing nails. Four overdriven nail depths were considered: flush, 1.6, 3.2, and 4.8 mm. Nails were spaced at 76 mm on center along the edges and 305 mm on center along intermediate supports. Edge nailing distance was 9.5 mm. Two specimens were constructed for each aforementioned overdriven depth. To determine a lower bound on capacity, 100% of the sheathing nails in a specimen were driven to the specified depth. Results from this study indicate that any level of sheathing-nail overdrive will reduce the capacity of a shear wall. Compared to specimens with flush-driven nails, specimens with nails overdriven 1.6 mm suffered 5% loss in strength and gained 1% in displacement capacity. Specimens with nails overdriven 3.2 mm had strength and displacement capacity reduced by 12 and 22%, respectively. Specimens with nails overdriven 4.8 mm fared poorly; strength was reduced 24%, and displacement capacity was reduced 56%. DOI: 10.1061/(ASCE)0733-9445(2002)128:7(898) CE Database keywords: Shear walls; Nails; Strength; Ductility; Wooden structures.

In coastal areas residential houses are often built on piles. The space below the first floor and the ground is sometimes enclosed. The enclosure walls are constructed to break away under severe wave-induced forces so that the forces transmitted through the breakaway walls to the building's foundation are not unduly large. Successful design of a breakaway wall therefore depends critically on knowledge of the ultimate strength of nailed fasteners and wall material and of the behavior of breakaway wall under wave-induced forces. In this research, laboratory tests were performed to determine the ultimate strength of nailed connections. Behavior and failure modes of breakaway walls from water waves were studied analytically and in a series of laboratory wave channel tests.

A method of modifying the lateral load - lateral displacement relationship obtained by a simple monotonic racking test to represent the skeleton hysteresis curve of an arbitrary dynamic response of a reinforced-masonry wall is proposed. The results of tests of 32 equal reinforced-masonry walls, tested by imposing monotonically increasing displacements, cyclic lateral displacements of two different shapes, and simulated displacement seismic response, have been used as a basis for the development of the procedure of modification. The amount of input energy, defined as the actuator work done to deform the specimens during the test, has been taken into account as the decisive parameter for carrying out this modification. On the basis of experimental results, correlation factors between the monotonic and cyclic hysteresis envelope curves, as well as stiffness and strength degradation parameters, which define the hysteretic rules, have been evaluated. Good agreement between predicted and experimental cyclic behavior of the walls has been obtained.

The influence of four different lateral displacement patterns used for experimental simulation of seismic behavior of masonry walls has been studied. Thirty-two equal reinforced-masonry walls have been tested by imposing monotonically increasing displacements; cyclic lateral displacements with amplitudes, stepwise increasing in predefined blocks of two different shapes and repeated three times at each amplitude peak; and simulated displacement seismic response. By imposing the same displacement pattern dynamically, higher values of lateral resistance and more rigid initial behavior of the walls has been obtained than statically. Higher resistance and larger ultimate displacements have been obtained by monotonic than by cyclic loading procedures of all types. At a higher level of vertical load, lateral resistance of the wall was improved, but deformability and ductility decreased at both, static, and dynamic types of loading at all load patterns.

All large spacecraft are susceptible impacts of meteoroids and pieces of orbiting space debris. These impacts occur at extremely high speeds and can damage flight-critical systems, which can in turn lead to catastrophic failure of the spacecraft. A long duration spacecraft developed for a mission into this environment must include adequate protection against perforation of pressured components by such impacts. This paper presents the results of an investigation into the effects of projectile shape and material on the perforation of aluminum dual-wall structural systems. Impact damage is characterized according to the extent of perforation, crater, and spall damage in the structural systems as a results of hypervelocity projectile impact loading. Analysis of the damage data shows that there are distinct differences in impact damage from cylindrical and sherical projectiles. Projectile density is also found to affect the type and extent of damage sustained by dual-wall structural systems.

Criticisms of tests used in a study on geosynthetic reinforced soil retaining walls is presented. Questions are raisedabout the suitability of three element tests, namely, the confined load-controlled extension test, the direct shear test and the pullout test. Justification for the previous study lies in that there are no standardized testing procedures for studies of that genre.

Researchers from the University of Florida have developed a hurricane simulator that employs an array of eight high-efficiency vane-axial fans to simulate a hurricane. This equipment can be used to mimic the effects of rain driven by a hurricane's wind to test water intrusion into walls and windows.

A softened strut-and-tie model for determining the shear strength of squat walls is proposed in this paper. The proposed model originates from the strut-and-tie concept and satisfies equilibrium, compatibility, and constitutive laws of cracked reinforced concrete. The shear capacities of 62 squat walls were calculated and compared with the available experimental results, and reasonable agreement was obtained. Based on the collected experimental data in this paper, the proposed physical model was used to study the effects of boundary elements, cyclic loading, and vertical loads on the wall shear strength. The softened strut-and-tie model can be further developed to improve the current shear wall design procedures by incorporating the actual shear resisting mechanisms in predicting shear strength of walls.

The out-of-plane performance of partially grouted, reinforced concrete masonry walls subjected to simulated seismic loading is investigated. The three full-scale walls, with and without openings, were constructed from 190-mm-thick concrete blocks and were 9.0-m long and 2.4-m high with two 2.5-m-long return walls. A minimum quantity of reinforcement permitted by New Zealand Standard 4229 was used, and additional diagonal bars were added to the corners of the bond beam at the top of the wall. The test results show that the specimens exhibited a ductile behavior with a 'pinched' shape of hysteresis response and that the ultimate out-of-plane capacities of the walls were considerably greater than the demands calculated using the current New Zealand masonry and concrete codes. The location and size of the openings influenced the load capacities significantly. Yield line theory gives a safe, conservative prediction of the out-of-plane capacity of partially grouted, reinforced masonry walls. Lateral deflection criteria are more important than force criteria in the out-of-plane design of walls.