This paper presents an evaluation of the cable loading
support capacity of red alder, Alnus rubra Bong., Sitka
spruce, Picea sitchensis (Bong.) Carr, and western hemlock,
Tsuga heterophylla (Raf.) Sarg., tail trees. Capacity is
measured in terms of combined stress resulting from
compression and bending, rather than the traditional methods...
This paper documents the development of a model which determines multiple stump anchor system displacement as a response to skyline load for four anchor rigging configurations: 1. Series multiple, 2. Tieback, 3. Elevated tieback, and 4. Equalizer block. It also documents the field testing of four two stump anchors rigged...
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...
A study was conducted to investigate the influence of root reinforcements on soil strength and the initiation of static liquefaction in forest soils. The design and operation was developed of an apparatus capable of modeling rainfall-induced shallow hill-slope failures that also permitted observation of the soil volume change tendencies at...
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...
High intensity sampling was undertaken to characterize the temporal and spatial
variability of oxidized nitrogen (NO3-N + NO2-N), ammonia-nitrogen (NH3-N), total
dissolved phosphorus, total unfiltered phosphorus and orthophosphorus (PO4-P) from two
adjacent small streams in Western Oregon's Coast Range, Deer Creek (303 ha) and Flynn
Creek (203 ha). Deer Creek...
The Lookout Creek Earthflow is located in the Cascade Mountain
Range in western Oregon. The Cascade Mountains are mainly volcanic
in origin, and deposits in and around the slide have a complex geomorphic
history,, affected by glacial, mass movement, and fluvial
processes. The currently moving land mass is about 1600...
The use of the triaxial test to characterize the strength of soils for civil engineering applications is widespread. These tests are typically conducted with confining stresses in excess of 5 psi. To characterize the
strength of a soil located in the upper layers of the subgrade of an aggregate
surfaced...
Peakflow frequency analysis is used in forest hydrology for designing stream crossing structures such as culverts and bridges. The traditional approach to frequency analysis is based on the assumption that the observed sample of peakflows represents a homogeneous population. It is not clear if using the "homogeneous" population of the...
Consider the bole of a tree to consist of a linear elastic material that is orthotropic with respect to the cylindrical coordinates. When the bole of a tree is subjected to resultant loads in the directions of the Cartesian base vectors, the S₁₁, S₂₂, S₃₃, and S₁₂ stresses in Cartesian...
Mass wasting events are a principal form of erosion that occurs on steep forest land throughout the Pacific Northwest. Numerous studies have reported that tree roots help stabilize steep forest land. A complete
understanding of the mechanism by which roots strengthen soil would enable modeling to more closely approximate field...
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...
An 18-year record of nitrate (NO₃), orthophosphate, total nitrogen and total phosphorus in four streams of the Bull Run
watershed, Oregon, was examined to determine its precision and time resolution. Of these four species, only NO₃ was found to be known to a sufficient level of detail for modeling and...
The forest products industry often uses intermediate-support cable logging systems to transport logs from the harvest site to a staging area. A method is presented to assist in the analysis and design of these cable systems. The method determines tensions in individual cables, forces on and stresses in the support...
Forest roads produce fine sediment with traffic during wet weather. If the forest road is connected to a stream it can be a source of turbidity and fine sediment that may be detrimental to aquatic organisms especially salmonids.
The goal of this work was to investigate turbid runoff during wet-weather...
The objective of this study was to provide first order observations of bed level changes occurring in streambed simulated culverts throughout an annual period. To accomplish this, 30 culvert sites were selected in Oregon and Washington, and monitored over, at least, a 2 year period. Streambed scour and redeposition data...
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Marvin Pyles
The objective of this study was to provide first order observations of bed
Many miles of roads are built in the Pacific Northwest Forests to provide access for logging and fire protection. Logging roads often cross steep mountainous terrain. Logging roads and the associated cut and fill slopes represent a discontinuity in the natural stress state in the soil mantle. These conditions result...
Research was conducted to study the behavior and
load carrying capacity of stump anchors. A field testing
program was undertaken to determine the response and
strength characteristics of second growth Douglas-fir
(Pseudotsuga menziesii) stumps ranging in diameter from
6 to 17 inches. Horizontal and vertical stump movements
due to an...
Twenty eight countersunk culverts in Oregon were evaluated to assess current conditions and hydraulic performance. The culverts were also assessed with respect to their stability, particularly when subjected to high flows. In general, the culverts were
found to be resistant to erosion and effective at conveying large discharges. Based on...
This thesis describes the results of a project conducted to determine the economics of forest road maintenance alternatives
between periods of timber harvesting. An open road and a closed road alternative will be compared to the economics of clearcutting an
entire area and obliterating the road system until reentry at...