Model testing has proven to be an effective tool in the study of
soil-structure systems. While primarily used in research work, this
method of evaluation is also applicable to the solution of many types
of complex design problems. Because of its workability and relatively
simple characteristics, sand is the most...
Nonlinear large deflection finite element analyses of a fabric
reinforced embankment on muskeg were performed to predict fabric
tension and the effect of fabric stiffness on embankment deflections.
The predicted fabric tensions were compared with the results of a
sliding block analysis, and show this simple analysis requires further
correlation...
Mass soil movements of four types; debris avalanche, debris torrent, debris slide and bank slough, were field inventoried in the Oregon Coast Range. A total of 104 mass movements were located in 21 undisturbed watersheds and 13 clearcuts harvested in the last six years. Failures associated with roads and landings...
Landslides are frequent in the steep forested regions of the Oregon
and Washington coastal mountain ranges. The need for forest products
has resulted in increasing logging activity in these marginally stable
areas. The occurrence of landslides has increased, which in turn has
focused greater interest in slope stability management.
Of...
During construction of the embankment at Blue River Dam
placement difficulties were occasionally experienced with the filter
zone sands. In the extreme condition construction equipment became
mired and part of the fill had to be removed and wasted. A
laboratory investigation was conducted on materials from the above
project to...
This paper examines the response of submerged model sand
slopes to vibration and the beneficial effects of placing rock revetments
on the face of the slope to prevent flaw slides.
Pore water pressure response and deflection were used as a
criteria for stability in an attempt to relate stability with...
This study was conducted to examine certain soil and hydrologic
properties of two major cohesionless soils Occupying 55% of the central
portion of the Oregon Coast Range. Knowledge of these properties was
desired to determine the role each played in the stability of slopes in
this region. Bohannon and Klickitat...
Published August 1980. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Oregon's forestry industry has and will continue to be a vital component of Oregon's economy, with twenty-two percent of Oregon's 1986 gross state product and thirty-nine percent of Oregon's 1986 gross manufacturing product related the forestry goods. An integral component to proper management of Oregon's forestry lands is Sustaining the...
The logarithmic-spiral (log-spiral) limit equilibrium procedure for slope stability analysis rigorously satisfies both force and moment equilibrium with a failure surface geometry formulated as a function of the soil’s angle of internal friction. Within the framework of limit equilibrium, this procedure has, in the past, been primarily limited to homogeneous...
Straw wattles are common erosion control devices used to trap sediment. This
thesis studies the relationship of straw wattles on slope stability through a case study
demonstrating their use on steep slopes (1.5H:1V) for the US20 highway realignment
project. Several surficial slope failures have occurred on these fill slopes, often...
Combinations of cohesive and cohesionless soils are often encountered
when evaluating the engineering properties of soils. The
stress-volume characteristics of the mixed soil are found to vary according
to the proportion of each component. If the cohesive soil
composes more than a certain fraction of the material, the magnitude
of...
The work upon which this publication is based was supported by funds provided by the United States Department of the Interior, Office of Water Research and Technology, as authorized under the Water Resources Research Act of 1964 and by the United States Department of Agriculture, Forest Service, Pacific Northwest Forest...
Nearly all soils are comprised of mixtures of coarse and fine particles. Behavior under mechanical and thermal loading of soil is strongly influenced (and in some cases, governed) by the ratio of coarse to fine particles. A better understanding of the fundamental behavior of soil mixtures will provide insight to...
The cyclic resistance of predominantly fine-grained soils has received considerable attention following ground and foundation failures at sites underlain by silt-rich soils during recent earthquakes. In several cases substantial ground deformation and reduced bearing capacity of silt soils has been attributed to excess pore pressure generation during cyclic loading. These...
Tsunami loading can cause sediment instability, which can compromise the structural integrity of coastal buildings and infrastructure. To understand the process by which a tsunami can cause sediment instability, it is necessary to understand how the pore water pressure in the soil changes during tsunami loading. Tsunami run-up causes the...
One of many important physical properties that must be known
to understand transport phenomena in soils is pore size distribution.
Presently the pore size distributions of soils are most commonly
obtained from soil water characteristic curves. The soil water characteristic
curves are usually obtained by the pressure plate technique.
It...
A literature review and a computer study are conducted to identify
the requirements of finite element programs for the specific use of discrete
analyses of reinforced soil structures. The utility of six commercially
available programs are appraised with respect to the identified
requirements. The results of the study are directed...
Deep foundations, including driven piles, are used to support vertical loads of structures and applied lateral forces. Many pile supported structures, including bridges, are subjected to large lateral loads in the form of wind, wave, seismic, and traffic impact loads. In many practical situations, structures subjected to lateral loading are...
Pile supported bridges are typically constructed near or in a natural or man-made
slope and are subjected to lateral loading. The current design method for laterally loaded
piles involves the use of Winkler's spring concept with the standard nonlinear p-y curves.
The available p-y curves were developed based on results...
A landslide inventory, statistical analyses and a Geographic Information System (GIS) are used to analyze landslide sites and potentially unstable terrain in the Oregon Coast Range. The objectives are to evaluate the efficacy of locating landslide sites with topographic variables and discriminate the difference between sites where landslides have and...
Six headwalls in the central Oregon coast range were selected for study of soil engineering properties and vegetativecharacteristics important for analysis of slope stability. The headwalls were considered representative of those which would be candidates for timber leave areas due to geomorphic and topographic features, including steepness of slope and...
This study presents the theoretical background necessary to model the bearing capacity of shallow and deep foundations in partially saturated soils. The conventional bearing capacity equations for shallow and deep foundations and the 𝛽-method for deep foundation side resistance have been modified to include the effects of matric suction and...
In many geotechnical design situations involving tight right-of-way constraints, Mechanically Stabilized Earth (MSE) walls are often the most cost-effective and reliable earth retention technology among available alternatives. However, few well-documented case histories with detailed material testing, instrumentation programs and construction observation of performance are available in the literature. Despite the...
A hypothesis used to explain the relationship between timber harvesting
and landslides is that tree roots add mechanical support to soil, thus increasing
soil strength. Upon harvest, the tree roots decay which reduces soil strength and
increases the risk of management -induced landslides. The technical literature
does not adequately support...
The John Day Reservoir, a large reservoir between the John Day and the McNary Dams on the Columbia River, must be lowered several feet below design level during salmon migration season in order to preserve anadromous fish habitat. This research assessed the north shore of the John Day Reservoir for...
As part of a long term study to evaluate the dynamic properties of naturally frozen soils, resonant frequency and cyclic triaxial
tests were conducted on Fairbanks silt samples from the U.S. Army Cold Regions Research and Engineering Laboratory Permafrost Tunnel, Fox, Alaska. The test methods subject right cylindrical test
specimens...
Two hilislope sites in the central Oregon Coast Range were instrumented and monitored for winter precipitation and saturated and unsaturated subsurface conditions. The study sites were near-ridge depressions typically known as headwalls. Based on results of the monitoring, two existing mathematical models
were adapted to predict piezometric levels in headwalls...
In unstable landscapes, modern pedological research explores the role of soils as products and indicators of geomorphologic change. Understanding the dynamics of hill slope pedogenesis is especially important in regions with limited, poor, or threatened soil resources. The island of Cyprus, situated in the eastern Mediterranean, is claimed by many...
This dissertation re-examines the now standard perceptual model of hillslope
hydrological response to rainfall, which includes the growth of a saturated wedge at the soil-bedrock interface or impeding layer. It also challenges the notion of bedrock impermeability and the assumption that the pattern of subsurface stormflow is determined by the...
The development of bioenergy from biomass has dominated the minds of forest engineering researchers over the last decade. One of the main themes that has been generated from that research is that bioenergy from biomass has major operational hurdles to overcome before becoming economically feasible. More directly, the impact of...
A simple debris-slide model, employing a digital elevation model (DEM) and geological data, was used in a geographic information system (GIS) to map slope stability in the Andrews Experimental Forest, located in the western Cascade Range in Oregon, USA. To evaluate the contribution of error in elevation to the uncertainty...