This thesis presents a procedure to identify and evaluate forest
arterial and collector networks. The procedure identifies those
decision criteria important in evaluating both the arterial and
collector networks and the specific facilities identified on these
networks. The procedure incorporates the decision criteria and results
from network and facility analysis...
Shallow landslides are destructive natural hazards that result in widespread losses, both of infrastructure and lives, throughout the world. To help mitigate the impact of landslide hazards, they are commonly characterized across a regional scale by (1) their location and likelihood using susceptibility maps, (2) their magnitude and frequency using...
This thesis presents an analytical, experimental and numerical study of the initiation of flows in a siphon for rapid and gradual openings of a downstream valve. Three initial water levels in the upstream tank and four final positions for the downstream valve were investigated. Two opening times of the downstream...
State Departments of Transportation (DOTs) are the primary owners of roadway infrastructure in the United States. Many of the employees of state DOTs work on roadway work sites, putting them at disproportionately higher risks of injury or fatality. A review of the literature determined that a combination of policies, standards,...
Resistance of reinforced concrete beams to diagonal tension
was studied in a series of papers which included beams without
web reinforcement and beams with various types of web reinforcement.
The magnitude of the loading causing the formation of initial
diagonal tension cracks depended primarily on the dimensions of
the cross...
The Manual on Uniform Traffic Control Devices prohibits positioning a bike lane right-adjacent to a vehicle turn-only lane to mitigate the potential for right-hook crashes. However, it provides no specific guidance on positioning with respect to bus-only lanes. This thesis describes a before/after safety evaluation of bike lanes positioned left...
Characterizing stakeholder behavior when making decisions in watershed management is a great challenge for planners, not only because plans are associated with physical uncertainties but also because stakeholders’ behaviors are influenced by numerous factors. Since stakeholders’ decision-making is linked to multiple types of uncertainty, communication of uncertainty to stakeholders by...
Improving safety education could contribute to the preparation of better professional engineers. Safety topics are not holistically embedded in transportation course curricula. This thesis explores the current state in which safety is being incorporated in transportation course curricula in terms of design and compares the uses of safety data in...
Mathematical models of the precipitation process are needed to
effectively use historical precipitation data in the design and
planning of engineering projects and for analysis of watershed
runoff behavior. Existing simple models based on the assumptions of
independent, identically-distributed random variables are
insufficient to describe several features of the historical...
The coagulation of effluent from the kraft pulping and
papermaking process was investigated. The amount of material
coagulated from saline mixtures of the effluent is determined
as a function of time, salinity, kraft effluent
concentration, and mixture pH. Individual sources of salinity
include sea water and several different solutions of...
A study was conducted to determine the quantity and distribution
of bark debris resulting from log rafting. Three distinct problems were
studied: (I) the quantity of bark dislodged from the logs while being
placed in the rivers and during transport in log rafts; (2) the percentage
of the bark that...
Waters of various salinities were secured from the Umpqua
estuary, the Umpqua River, and the open ocean near the mouth of the
estuary. The rate of oxidation of sulfides in these various waters
was investigated to assess the potential longevity of free sulfides in
estuarine waters.
The rate of disappearance...
A rapid expansion of population and industrialization in recent
years has created new and difficult problems in water resources
management. Prudent management of water quality will require that
more efficient methods be developed for evaluating large volumes of
data on complex river systems, and tabulating the results in a form...
This paper investigates a particular bridge construction technique
which could result in a significant torsional moment. The
structural member under consideration is a prestressed concrete
girder for which no torsional consideration is made.
Torsional shear stresses can be adequately approximated for
an I-shaped girder. Laboratory model tests were performed to...
There are several factors which affect the cost and efficiency
of a structure. The most important and basic factors are: the predominant
stress, the way the structure carries the loads and the
shape of the structure.
The structures in which the predominant stress is not bending
have been chosen to...
Driving simulation is widely accepted as a safe, effective, and economical alternative for investigating driver behavior in a variety of contexts. However, in order to apply simulator-based research results to real-world settings, the performance measures acquired through simulated driving experiments must first be validated. This research was aimed at validating...
At Site-300, Lawrence Livermore National Laboratory (LLNL), CA,
trichloroethene (TCE) is present along with tetraalkoxysilanes such as tetrabutoxysilane
(TBOS) and tetrakis(2-ethylbutoxy) silane (TKEBS), as subsurface contaminants.
Intrinsic transformation of TCE to cis-dichloroethene (c-DCE) was observed in the
groundwater at locations co-contaminated with TBOS or TKEBS. Attenuation of TBOS
and TKEBS...