bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resilient Modulus Test — Triaxial Cell Interaction
Authors: Boudreau RL , Wang J 
Published: April 2008

During developmental work by the Strategic Highway Research Program (SHRP, 1987–1992) and the Federal Highway Administration (FHWA, 1993-present), it was recommended that knowledge and assessment of triaxial equipment and sample interaction be correctly applied to both test command and data reduction routines for the accurate measurement of resilient modulus properties of unbound materials using external instrumentation configuration. This concern is briefly addressed in the American Association of State Highway and Transportation Officials (AASHTO) test method T307-99, under paragraph 8.3.2.1. The paragraph refers only to calculations necessary to correct for the proper magnitudes of seating load based on known properties of the triaxial cell. The method does not contain information describing the methods and calculations needed to consider these parameters in the data reduction portion of the test. Further, the test method does not address other influences unique to a triaxial testing cell, namely frictional forces resulting from poorly manufactured or improperly designed seals, alignment issues and compliance.
This paper addresses the sensitivities of the results due to appropriate and inappropriate interpretation of the correction factors necessary, as well as influences of seal drag forces. The sensitivities have been calculated for two specific triaxial cells. Note that each triaxial cell and instrumentation configuration possesses unique values needed for the correction. Generally, the larger the triaxial cell (larger rod diameter, larger mass of rod), the greater the influences of the uplift and static weight components of load.
Users must be knowledgeable about their test equipment and the ability of the software to correctly apply proper loads and properly assess these loads for the correct calculation of resilient modulus. Further, physical tolerances must be developed for triaxial cells with respect to seal drag, alignment and compliance. These issues are extremely important when comparing results between laboratories, as the errors associated with miscalculation, misinterpretation or incorrect measurement of loads can result in variations outside the precision of the test itself.
Resilient Modulus — Pavement Subgrade Design Value
Authors: Boudreau RL 
Published: April 2008

Much resilient modulus research work has been completed recently, mostly as part of the Long Term Pavement Performance (LTPP) study. This work has led towards the adoption of the resilient modulus test procedure, T307-99, in the current release of the American Association of State Highway and Transportation Officials (AASHTO) Tests. Neither the test procedure nor the current design guideline addresses how to approach selecting a design resilient modulus value from the fifteen stress-dependent numbers generated by the laboratory test.
Cohesive and non-cohesive subgrade soils are generally nonlinear inelastic materials, thus their stiffness is dependent on the stress condition subjected to. Recognizing this, the project-specific case study discussed in this paper examines the stress-dependency of soils encountered through laboratory determination of resilient modulus.
This paper uses a recognized constitutive model and layered elastic methodology approach (iterative solution) to objectively interpret results from a laboratory test program and apply the results for input into the 1993 AASHTO Design Guide for Pavement Structures (or DarWIN).
Through the use of the stress-dependent constitutive model: Mr = K1(Sc)K2 (S3)K5 and simple 85th percentile statistics, the process created uses the predicted subgrade modulus values at an assumed stress state. The 85th percentile value is selected as input into the 1993 AASHTO structural number (SN) requirement. A conventional pavement system (layer type and thickness) is then developed using typical mechanistic properties of asphalt concrete and aggregate base, which satisfy the SN. The layered elastic model ELSYM5 is then used to approximate vertical and horizontal stresses at the top of the subgrade layer. These stresses are compared to those assumed values used in the initial iteration. Adjustments are made and iterations continue until the values used to predict subgrade modulus reasonably match the calculated stresses in the pavement system.
The final iterated value for resilient modulus is the design resilient modulus. It is recommended that this design value be used to calculate pavement thickness requirements for all pavement types under consideration for the project.
Quality Control Guidelines for Factory Applied Structural Silicone Glazing
Authors: Carbary LD , Gustafson J 
Published: April 2008

Factory applied structural silicone application has become the preferred method of structural silicone glazing and panel attachment within the curtainwall industry. This preference is due to the fact that the factory environment can be environmentally controlled, quality control practices are easier implemented, and supervision is readily available compared to the field environment. This paper describes the proper methods for quality control learned by the authors over the past 15 years and a description of the benefits.
Suggested architectural submittals regarding quality control guidelines for the surface preparation, structural silicone application, adhesion verification, and unit deglazing are discussed. Reporting this data in a logical fashion is essential so that a review by consultants, inspectors and / or building officials can be done. Guidelines for submitting this data are included. Interpretation of the data is a key part of this paper because the responsible parties must have a clear set of data to review to ensure the building owner of a successful project.
Included in this paper is a unique test method utilizing a portable tensile testing device to quantify accurately the structural silicone strength to verify that the installed sealant meets the minimum requirements set forth by ASTM Standard Specification for Structural Silicone Sealants (C1184-00). This quick method of testing deglazed panels can provide accurate tensile strength of the installed silicone in 24–48 hours after deglazing without destroying the curtainwall panel assembly. Immediately after testing the installed structural silicone, the curtainwall panel can be reglazed. This unique method is beneficial because the alternative pressure testing of curtainwall units to the point where the structural silicone would reach the requirements set forth in ASTM C1184 would substantially overload and destroy the curtainwall panel assembly. Suggested specification requirements regarding the type and frequency of quality control tests are given. When these requirements are followed, a reduction in the risk of failure with structural silicone glazed projects is obtained. Guidelines that are presented are state of the art, in concert with ASTM Standard Guide for Structural Sealant Glazing (C1401-02) and will ensure long-term performance of structural silicone glazed curtainwalls.
Minimum Retention Settings: Examining Prediction Methods
Authors: Scher IS , Mote CD 
Published: April 2008

By comparing the forces at the bindings required to ski normally to the forces recommended by the current setting standards, we evaluated the currently used method for selecting the ski-binding release forces for an individual. For 32 subjects (including beginning skiers through members of professional racing teams; 48 to 103 kg; 16 to 60 years of age), the lateral force at the toe binding and the vertical force at the heel binding were measured during skiing experiments. For each subject, the maximum lateral toe force and vertical heel force were measured in runs without falls and without binding releases.
For 20 of the 32 subjects, the current setting standards allow forces at the bindings that far exceed the forces required to ski in at least one release mode. Fifteen of the subjects generated maximum lateral toe forces during normal skiing that were less than 65% of the magnitude recommended in the current standards. For another 15 subjects, the maximum vertical heel force needed for normal skiing was less than 50% of the force recommended by the setting standards.
In order to improve the accuracy of the setting standards for the individual, we examined the relationships between the required settings and the variables used in the current standards (weight, height, age, and skier type) to select the settings. Multiple linear models that used skier weight, height, age, and skill level could not predict accurately the optimal settings for an individual (multiple R correlation coefficients were 0.57 and 0.73 for toe and heel settings). Furthermore, weight was found to be a poor predictor of the required settings, with all linear and quadratic correlation coefficients less than 0.46.
Nonanthropometric variables were considered for use in a predictive model for the best settings. Slope steepness and grooming were examined for a relationship with the forces generated during skiing, but no statistically significant relationships were found. Skier attitude, confidence, and skiing style appear to be related to the required settings. Measurements of the forces during low-velocity maneuvers before a day of skiing, which were found to generate high forces more often than downhill skiing and which incorporate skier confidence and style, could provide a better method of determining the settings for the individual skier.
Injuries in Alpine Skiing, Telemarking, and Snowboarding
Authors: Ekeland A , Rødven A 
Published: April 2008

A central ski patrol-based registration of skiing and snowboarding injuries was performed by the Norwegian Ski Lift Association during the winter seasons 1996/1997 and 1997/1998.
At total of 3915 injuries and 32.894 million lift transports were recorded during the two seasons, giving an injury rate of 1.2 injuries per 1000 skier days or per 10 000 lift transports. Most of the injuries occurred during alpine skiing (57%) and snowboarding (34%), whereas telemark skiing accounted for 9% of the injuries. Many injured snowboarders suffered wrist injuries (29%), compared to only 4% for alpine and 3% for telemark skiers. Knee injuries were more common among injured alpine skiers (26%) than among telemarkers (13%) and snowboarders (6%), but the percentage of knee injuries was double as high for females as for males in all three disciplines. The injured telemark skiers suffered three times as many ankle injuries (13%) as alpine skiers (4%) and snowboarders (4%).
Injured snowboarders suffered more fractures (33%) than alpine (22%) and telemark (20%) skiers. Lower leg fractures were recorded for only 3.6% of the injured alpine skiers 20 years and older, whereas this injury accounted for 20% of the injuries among alpine skiers 12 years and younger. Injured alpine beginners suffered more knee injuries than experts. Almost half of the injured snowboarder beginners (44%) suffered wrist injuries compared to only 14% of the experts, but injured experts suffered more head, shoulder, and ankle injuries than beginners.
In conclusion, injured alpine skiers are most prone to knee injuries. Lower leg fractures have become uncommon among adult skiers but are still a common injury in children. Injured snowboarders are prone to wrist injuries and injured telemark skiers to ankle injuries. The percentage of knee injuries among females is twice that of males in all three disciplines.
Arthroscopically Assisted Operative Treatment of the Tibia Plateau Fractures from Downhill Skiing
Authors: Yamagishi T , Fujii K , Tsuji M , Kurosaka D 
Published: April 2008

Twenty-two skiers suffered fractures of the tibial plateau and eminence of the tibia from downhill skiing between 1993 and 1998. Sixteen cases of the 22 tibial plateau fractures were treated with an arthroscopic reduction and internal fixation of the articular surface without a formal arthrotomy or detachment of the anterior horn of the lateral meniscus. The average age of the patients at the time of surgery was 40 years (ranging from 24 to 55 years). Fourteen patients were male and eight patients were female. Twelve of these plateau fractures were classified according to Schayzker [15]. The distribution was as follows: one case Type I; three cases Type II; four cases Type III; two cases Type IV; zero case Type V; and two cases Type VI; ten cases of intercondylar eminence of the tibia were classified according to Meyers [13]; six cases of Type I; one case of Type II; three cases of Type III.
The Type II and III, according to Schayzker's fractures [15], required elevation of the depressed fragments from below through a bony window, bone grafting the resultant metaphyseal defect, and rigid internal fixation using an L-buttress plate. The principles for arthroscopic reduction and internal fixation of tibial plateau fractures are essentially the same as those of conventional open reduction and internal fixation. The split depression and joint depression fracture types were suited for arthroscopic reduction and internal fixation. The treatment goals are restoration of joint congruity, restoration of normal alignment, joint stabilization, and, ultimately, prevention of degenerative arthritis. There were no valgus malunions and no non-unions: radiographic findings of early degenerative changes were not seen in 14 of 22 patients at an average of twelve months follow-up (range from 6 months to 60 months).
Monitoring Deformations on the Church of the Transfiguration
Authors: Vahrameeva TI , Lubimov V , Tsvetkov VJ 
Published: April 2008

The Church of the Transfiguration or Tserkva Preobrazhenskaya, located on Kizhi Island, Karelia, Russia, is a unique monument of the 18th century that has no analogs in world architecture. It is included on the UNESCO list of the most significant monuments constituting the World Cultural Heritage. The Kizhi Pogost includes three structures: the Tserkva Preobrazhenskaya (the summer church), the Tserkva Pokrovskaya (the winter church), and the Bell Tower. The Church of the Transfiguation is the focal point of the ensemble and is constructed of a system of log octagons that rise to a height of 34 meters (111.5 ft).
Typically, wooden buildings in Northern Russia last no longer than 250–300 years. The Church of the Transfiguration reached this critical age in the last quarter of the 20th century. This fact highlights the importance of restoration work and the monitoring of the general condition of the building.
A precise description of the wood log structure of which the church is composed is given. The monitoring of seasonal movement of the building is given starting from the erection of a steel frame inside the building in 1981 to 1983. Monitoring of building deformations have been monitored to analyze the interaction of the log structure and the steel frame.
Measurements conducted and discussed in the paper reveal interesting data regarding the seasonal movement of the structure as a whole and the behavior of the elements of which the structure is composed. Based on the systematic monitoring of the building it can be concluded that, apart from the seasonal movement, the building is stable. The observations did not reveal interaction between the steel framework and the wood structure.
Inspection and Evaluation of Decay in Log Structures
Authors: Mattsson J 
Published: April 2008

The decay of wood materials in buildings due to fungal attack and the activity of wood boring insects is not uncommon. Such decay normally causes restricted areas of damage, but in some cases, the damage can be extensive and pose a serious problem. for this reason maintenance and repair are a natural part of a building's life cycle. The best way to restrict damage is to discover problem areas as soon as possible. However, all preventive work against damage and rehabilitation of damaged areas must be based on a fundamental knowledge and understanding of biological mechanisms. Otherwise there is a great risk of taking incorrect measures. Such mistaken efforts not only cause needless expense, but in cases of listed or protected buildings incorrect treatment can also cause damages that are not repairable — damages that may be more ruinous than the original decay that the repairs were designed to address.
Wood decaying fungi and wood boring insects occur everywhere where wood is used as a building material and can cause damage in most parts of those structures. The activity of these biological organisms vary due to microclimatic factors such as moisture content in the wood and temperature. The result is that damage that appears identical from building to building may actually develop very differently due to climatic factors. For this reason it is of primary importance to carry out a careful and thorough examination of all damage.
The Treatment of Fungal Growth in Heritage Structures in Denmark
Authors: Munck O , Fode J 
Published: April 2008

Wood has always been a constituent and natural part of buildings. In ancient Danish buildings, wood was utilized for timber frames, floor beams, roof rafters, partitions, windows, and doors. Thoughtfully applied, wood is practically imperishable. However, even structural timber that is protected within the building envelope can become worn due to hundreds of years of use, or rotten due to the lack or improper maintenance of the roof and the facades.
This article deals with some of the construction principles that apply to heritage buildings in Denmark and with the problems connected with restoration of listed buildings after a wood-decay fungi attack. In relation to this we will describe some new remedial treatments, which are applicable especially when preservation of original structural timber is an absolute necessity.
Increases in Fatigue Crack Growth Rate and Reductions in Fatigue Strength due to Periodic Overstrains in Biaxial Fatigue Loading
Authors: Varvani-Farahani A , Topper TH 
Published: April 2008

Fatigue crack growth under biaxial constant amplitude straining (CAS) and a strain history having periodic compressive overstrains (PCO) were investigated.
A comparison of the growth of fatigue cracks under constant amplitude straining and under strain histories having periodic compressive overstrains revealed that the morphology of the fracture surface near the crack tip and the crack growth rate changed dramatically with the application of the compressive overstrains. When the magnitude of the compressive overstrains was increased, the height of the fracture surface irregularities was reduced as the increasing overstrain progressively flattened fracture surface asperities near the crack tip. The reduced asperity height was accompanied by drastic increases in crack growth rate and decreases in fatigue strength.
Crack opening stress measurements for biaxial fatigue cracks made using confocal scanning laser microscopy (CSLM) image processing of the crack profile, showed that the biaxial cracks were fully open at zero internal pressure for block strain histories containing in-phase periodic compressive overstrains of yield point magnitude. Therefore, for the shear strained samples there was no crack face interference and the strain intensity range was fully effective. For PCO tests with biaxial strain ratios of -0.625, and +1, effective strain intensity data were obtained from tests with positive stress ratios for which cracks did not close. The strain intensity factor ranges derived from popular fatigue life parameters were used to correlate fatigue crack growth rates for the various strain ratios investigated. These parameters all involved the shear strain range, and the normal strain range acting on the maximum shear strain plane. For various biaxiality ratios, the ratios of the effective strain intensity factor range to the constant amplitude strain intensity factor range at the threshold were found to be close to the ratios of the closure free fatigue limit obtained from effective strain-life to the constant amplitude fatigue limit.
Modern, Low Fire Hazard, Thin Wall Insulated Wire—A Complex Balance of Properties
Authors: Gardner D , Whiteley RH 
Published: April 2008

The complexity of electrical systems required for modern mass transport systems have been increasing over recent years. The size and weight of wire and cable installations are now important issues. The technical solution to these issues has been to move from thick and medium wall insulations to thin wall insulations. In addition, increased safety levels with respect to fire hazard properties are now demanded by the industry. Ignition resistance and reaction to fire are now considered to be of critical importance, especially for underground transit systems. The production of smoke, acid/corrosive gases and toxic fire products must all be minimized.
The functional properties of the wire, however, must not be compromised by these additional requirements of thin wall insulation and low fire hazard properties. A typical specification for such a wire therefore reflects a complex balance of properties.
This paper describes the elements of such specifications and reviews some of the test methods used to define the properties of the wire.
Qualification of Epi Layers and Interface Properties by an Improved μ-PCD Technique
Authors: Pavelka T 
Published: April 2008

The microwave photoconductive decay (μ-PCD) and the surface photo voltage (SPV) techniques are proved to be powerful methods in the qualification of semiconductor bulk materials. They are applied best for standard wafers with homogeneous material quality. However, both methods have their limitations when measuring epitaxial layer (epi) wafers or silicon on insulator (SOI) structures. In its conventional realization the SPV measurement is limited by the active layer thickness. On the other hand an epi layer grown on highly doped substrate typically does not generate high enough signal in a μ-PCD measurement.
The aim of the present work is the introduction of a new, improved microwave photoconductive decay technique with sensitivity exceeding that of the conventional techniques by orders of magnitude. It is shown that such a method is not only able to provide material quality in case of epi and SOI structures but can help also in the qualification of interface properties.
Data are presented to show the above statement including maps of contamination distributions in epi structures.