Woodpile Research Articles

Classroom Exercises in IP Modeling: Su Doku and the Log Pile

Two puzzles are presented and discussed with a view to using them as classroom drill exercises in Integer Program Modeling. Mathematical formulations are presented for each puzzle and working models are offered as a resource for instructors.

Modeling and Validating the Grabbing Forces of Hydraulic Log Grapples Used in Forest Operations

The grabbing forces of log grapples were modeled and analyzed mathematically under operating conditions when grabbing logs from compact log piles and from bunch-like log piles. The grabbing forces are closely related to the structural parameters of the grapple, the weight of the grapple, and the weight of the log grabbed. An operational model grapple was designed and tested to validate grabbing forces of the mathematical models while grabbing logs from five alternative diameter classes under two different working conditions. The working conditions and log sizes affected the grabbing forces significantly. Validation results suggest that the mathematical models developed can be used to estimate the grabbing forces required in the design process of log grapples. The results can be used by equipment manufacturers and researchers involved in the engineering design of grapples used in harvesting operations.

New Method for Evaluating Soundness of Wooden Pile Piers

The Impact Vibration Test is now a recognized method for evaluating the soundness of bridge substructures. This method focuses on the natural frequency of the pier under test, since it clearly shows the condition of the bearing capacity of the foundation and the soundness of the pier. The measured and standard values of the pier's natural frequency are compared for evaluation, and it is judged to be "sound" when the former is sufficiently higher than the latter, and as unsound otherwise. The standard value of the natural frequency is calculated by statistical analysis using several parameters, such as the pier height, pier width and the weight of the superstructure, although these parameters are highly correlated with the natural frequency. But the conventional standard value calculation formula does not have physical significance at all. Entirely based on a design concept for foundations, this paper introduces a new and progressive method for the standard value of the natural frequency of wooden pile foundations.

Fiber Reinforced Polymer Composite–Wood Pile Interface Characterization by Push-Out Tests

Structural restoration of spliced or damaged wood piles with fiber reinforced polymer (FRP) composite shells requires that shear forces be transferred between the wood core and the encasing composite shells. When a repaired wood pile is loaded, shear stresses develop between the wood pile and the FRP composite shell through the grouting material. Alternatively, shear force transfer can be developed through mechanical connectors. The objective of this study was to characterize the interfaces in wood piles repaired with FRP composite shells and grout materials. Two interfaces were studied: wood pile/grout material and a grout material/innermost FRP composite shell. A set of design parameters that control the response of both interfaces was identified: (1) extent of reduction of cross section of wood pile due to deterioration (necking); (2) type of grout material (cement-based or polyurethane); (3) use of mechanical connectors; and (4) addition of frictional coating on the innermost shell. Push-out tests by compression loading were performed to characterize the interfaces and discriminate the effect of the design parameters. The outcome of the push-out tests was evaluation of the shear stress and force versus slip response and characterization of the failure mechanism. A set of repair systems that represent different combinations of the design parameters was fabricated and the interfaces evaluated. It was found that the combination of cement-based grout and polymer concrete overlay on the innermost shell provided the most efficient shear force-slip response. A simplified piecewise linear model of shear stress versus slip at the wood/grout and grout/FRP composite interfaces with and without mechanical connectors is proposed to synthesize the experimental response.

Freeze‐Thaw Resistance of Fiber-Reinforced Polymer Composites Adhesive Bonds with Underwater Curing Epoxy

A prefabricated fiber-reinforced polymer (FRP) composite shield or jacket was developed to repair wood piles in the field. Cylindrical E-glass/vinyl ester composite shells were bonded underwater to encase damaged wood piles. The resistance to freeze–thaw cycles of an underwater curing epoxy adhesive was evaluated. The standard test procedure for single-lap shear adhesion for FRP composite bonding, ASTM D5868, was selected. A standard procedure for freeze–thaw cycling exposure was adopted. The effect of freeze–thaw cycling exposure on the performance of the adhesive bond was discriminated by comparing the lap shear strength and the mode of failure of control and exposed samples. It was found that the lap shear strength is substantially reduced by exposure to freezing and thawing cycles. A change in the mode of failure from predominantly adhesive type to combined adhesive/cohesive type was noticed after exposure.

Assessment of Wood Pile Deterioration due to Marine Organisms

In this paper a description of the major groups of marine organisms causing significant wood pile damage is presented. These organisms are divided into two groups: (1) fungi and (2) marine borers. The basic physical and biological characteristics of these organisms are presented, as well as the type of damage that they cause in marine wood piles. The objective of the study presented in this paper is to characterize deterioration of wood piles due to marine organisms and to assess damage in the wood pile zones of a typical waterfront installation. Marine borer activity in Maine coastal waters is assessed through a survey directed to harbor masters; the results of the survey are correlated with historic data. In order to illustrate the type and extent of wood pile deterioration, two case studies in Maine harbors are presented.

静岡県の茶産業に見られた簡易住居の復元(建築歴史・意匠)

In Makinohara in Shizuoka Prefecture, the farmers built primitive temporary dwellings in the tea plantations for use during cultivation and harvesting. These houses were built from the late 19th century until the 1960s, but none survive today. We reconstructed this example with the assistance of the farmers. The construction methods used in this house include a number of noteworthy features. The foundation consists of wooden piles and the posts are bamboo-poles tied to the piles. The roof structure is made without rafters or purlins. The piles are convenient for building a structure on weak ground or sandy soil. The binding poles make it possible to achieve a horizontal floor despite the difficulty of creating a stable foundation. We do not know how long these techniques have been in use, but we are convinced they were important in the construction of ancient houses.

Inspection of the Bed and Foundations beneath the South Facade of the Mikhailovskii Castle in Saint Petersburg

Monies for restoration of the Mikhailovskii Castle, which were set aside, among other things, for reestablishment of the Voskresensk Canal that had previously existed near the south facade of the castle, have been earmarked for the 300th anniversary of the city of Saint Petersburg. Trenching of the deep (up to 4.4 m) canal alongside the foundation of the castle required that the condition of the latter's structures be ascertained. An inspection was conducted by the publicly owned joint-stock company GeyaBVN in the summer of 2202. Check analyses of existing wooden piles, and also the bearing capacity and deformations of the bed indicated that restoration of the canal would not result in loss of stability and unacceptable deformations of the bed when certain requirements regarding work production are observed.

Effect of oak wood heating on cognac spirit matured in new barrel: a pilot study

<p style="text-align: justify;">This study investigates the influence of different levels of wood heat treatment on the quality of a Cognac spirit using a pilot barrel model. The pilot barrels were composed of a stainless steel cylinder closed at both ends by a piece of stave. The aim of the study was to analyze the impact of wood heat treatment on Cognac in both analytical and sensory terms and to confirm the validity of the pilot barrel model. The findings give a relatively wide view of the influence on the composition of Cognac of new wood heated at different temperatures. Heating gave notes of «vanilla» and «toasted» to the spirit while excessive heating led to lower quality with the appearance of «fungus» and «dusty». The good quality of the spirits obtained validates the pilot barrel as a model for the extraction of wood compounds by spirit.</p>

Experimental characterization of FRP composite-wood pile structural response by bending tests

A special prefabricated fiber reinforced polymer (FRP) composite shield or jacket was developed to repair wood piles in the field. Two types of load-transfer mechanisms between the wood pile and the FRP composite shield were developed and tested: (1) cement-based structural grout; and (2) steel shear connectors with an expanding polyurethane chemical grout. The objective of this paper is to characterize the structural response of full-size pre-damaged wood piles repaired with the FRP composite shield system. A three-point bending test procedure was used to simulate the response of a pile subjected to lateral loads. The load-deformation response, deflected shape profile, relative longitudinal displacements (slip), strain distribution, ultimate bending moment capacity and mode of failure were evaluated. Wood piles were pre-damaged by reducing approximately 60% of the cross-section over a portion of the pile. It was found that a pre-damaged wood pile repaired using the FRP composite shield with cement-based grout exceeded the bending capacity of a reference wood pile. The repair system using the FRP composite shield with steel shear connectors and polyurethane grout did not fully restore the bending capacity of a reference wood pile; however it can be used for marine borer protection when wood damage is not critical.

The Appearance of a Strange Kind of ‘Sea-Worm’ at the Dutch Coast, 1731–1735

Between 1731 and 1735 a large variety of texts were published in the Dutch Republic concerning the appearance of an unknown species of worms at the seashore. Because soon after this discovery it became clear that these worms were ravaging the wooden piles that formed an essential part of the defence-system against the sea, their appearance caused great concern. Although around 1680 the presence of ‘sea-or pile worms’ had already been reported by dyke inspectors of the province of North Holland, not before 1731 the concern for the worm-plague resulted in a public ‘anxiety’ which became crystallised within the printing press. By examining the different perceptions and explanations of the appearance of the worms, and to place these findings within the early eighteenth-century Dutch context, this paper will try to provide an answer to the question why the discovery of the sea-worm became such an important issue in the Dutch public debate of the 1730s.

Effects of Tong Shapes on Hydraulic Log Grapple’s Performance in Loading and Unloading Operations

Three log grapple tong shapes used in logging operations; horizontal ellipse, circle, and vertical ellipse, were analyzed mathematically and mechanically. The three same tongs as defined were designed and tested to evaluate their performance in terms of grabbing unrestrained log piles. Three operational variables; grabbing force, grabbed log weight, and unit grabbing force were examined using five diameter classes of logs for each set of tongs. Results indicated that the grabbing performance of log grapples with horizontal ellipse tongs is better than the grapples with circular tongs or vertical ellipse tongs.

Discovery, distribution, and abundance of the newly introduced mosquito Ochlerotatus japonicus (Diptera: Culicidae) in Connecticut, USA.

The earliest documented specimen of an exotic east Asian mosquito Ochlerotatus (Finlaya) japonicis japonicus (Theobald) in the Western Hemisphere is reported along with the results of a state wide survey to determine the distribution and abundance of this mosquito in Connecticut. Ochlerotatus japonicus was collected from 87 locations in eight counties. It is established throughout the state and occurs in a variety of natural and artificial container habitats including discarded tire casings, bird baths, wooden barrels, porcelain bath tubs (used for watering animals), plastic milk cartons, toys, vinyl tarpaulins (covering wood piles and swimming pools), exposed rock holes in stream beds, tree holes, subterranean catch basins, surface water rain pools, and spring-fed depressions. Larvae were particularly common in containers with water, decaying leaves, and algae, in shaded and sunlit areas and, in rock-pool habitats along streambeds, in association with Ochlerotatus atropalpus (Coquillett). Adult females were collected in sod grass-infused gravid and CO2- baited light traps, from early June through October, with peak collections in September. Biting females were collected by human bait method augmented with CO2, verifying its capacity to feed on humans. The ovitraps used in this study were not effective for recovering this species. Our results suggest that Oc. japonicus was introduced into Connecticut between 1992 and 1998. Because of the ability of Oc. japonicus to transmit West Nile virus, and because of the recent detection of this virus in field-collected specimens, the introduction of Oc. japonicus is considered a significant public health development.

Non-Host Volatiles Disrupt the Response of the Stenographer Bark Beetle, Ips sexdentatus (Coleoptera: Scolytidae), to Pheromone-Baited traps and Maritime Pine Logs

Non-host volatiles (NHV) were tested on antennae of Ips sexdentatus with coupled gas chromatographic-electroantennographic detection (GC-EAD). Significant antennal responses were found to aggregation pheromone components, ipsdienol and amitinol, an attraction inhibitor, verbenone, and non-host bark volatiles extracted from Betula pendula, including trans-conophthorin (tC) and alcohols. The tC, a blend of three green leaf alcohols (C6-alcohols), and a blend of two bark alcohols (C8-alcohols) were tested in combination for their ability to disrupt the attraction of the stenographer bark beetle to pheromone-baited traps, unbaited and pheromone-baited maritime pine logs. The strongest disruptive effect resulted from the addition of the tC combined with the blends of NHV alcohols at high release rate, achieving an 83% reduction in trap catches, 89% reduction of attacks on unbaited pine logs, and 60% on baited logs. It is proposed that the two types of NHV have an additive effect, tC playing a major role in pheromone disruption while the alcohols would interrupt host specific signals. The results suggest that I. sexdentatus uses both bark and green leaf volatiles from non-host tree species in the host selection process. These NHV are promising disruptants, which could be used to prevent stenographer bark beetle attacks on log piles or standing trees in forest. A mixture of conifers and broad-leaved species would also disturb olfactory guided host selection supporting the assumption that more diverse forests are less prone to pest insect outbreaks.

Un pont (?) antique (?) à Tours / An ancient (?) bridge (?) at Tours

The exceptionally low level of the water in the Loire river at Tours in September 2000 allowed the discovery of groups of wooden piles which may be parts of an ancient bridge. That structure apparently older than the medieval bridge built in the first half of 11th century could be from Roman times.

DISPERSAL OF TOMICUS PINIPERDA (COLEOPTERA: SCOLYTIDAE) FROM OPERATIONAL AND SIMULATED MILL YARDS

AbstractThe pine shoot beetle, Tomicus piniperda (L.), is an exotic pest that is regulated by federal quarantines in the United States and Canada. Mark–release–recapture experiments were performed with infested logs coated with fluorescent powder to determine if overwintering beetles in logs would leave a mill yard if infested logs were transported to sawmills in uninfested areas. Overwintering T. piniperda adults were marked with powder as they emerged in spring. Dispersal studies were conducted in four simulated mill yards and five operational sawmills to determine whether T. piniperda would colonize only the log pile in which they overwintered, fly to nearby log piles, or disperse beyond the mill yard. Each simulated mill yard was composed of 36 uninfested red pine logs, Pinus resinosa Ait. (Pinaceae), and 12 α-pinene-baited funnel traps set up to 100 m from a central release pile of six uninfested red pine and nine infested logs of Scotch pine, Pinus sylvestris L. At the five operational sawmills, baited funnel traps were set up to 400 m outside of each mill yard. Overall, 482 T. piniperda galleries were found on the experimental logs recovered from the four simulated mill yards combined. Tomicus piniperda adults dispersed and attacked the most distant logs at 100 m from the release point in the simulated mill yards. Likewise, adults were captured in baited funnel traps at distances up to 230 m in simulated mill yards and 250 m around operational sawmills. Although numbers of recaptured T. piniperda were generally low, in all cases some adults dispersed outside the mill yards despite the presence of abundant suitable breeding material. Therefore, logs containing overwintering adults pose a risk of spreading T. piniperda if not processed prior to initiation of spring flight.

A Road Closed: Rural Insurgency in Post-Independence Pennsylvania

Something remarkable happened in the Pennsylvania countryside in the years following the federal Constitutional Convention of 1787: large numbers of farmers closed the main roads that led into and out of their communities. During an eightyear period, fall 1787 through fall 1795, rural Pennsylvanians obstructed roads at least sixty-two times. 1 The road closings were not confined to any particular county or region: farmers blocked highways in new backcountry settlements and in the established communities surrounding Philadelphia. And while road closings were more frequent in the central and frontier parts of the state, barriers appeared in roadways only twenty-five miles beyond the Quaker city. (See map.) The obstructions were usually formidable, often making roads impassable for many months at a time. Throughout Pennsylvania, farmers constructed six-foot-high fences that stretched fifty feet across the highway. Some farmers felled trees across roads or hauled timber into log piles that sometimes measured thirty feet wide and forty feet long. Others blocked roads with heavy stones, brush, and decaying logs. Still others scarred roadways with eight-foot-wide, five-foot-deep ditches large enough to halt any wagon or coach. One group in the southeastern county of Chester shoveled enough dirt out of the main highway to Philadelphia that they created an impassable crater measuring fifty feet in circumference and seven feet deep. Farmers in two other eastern counties flooded roads by carving out canals to nearby waterways. On the

The Early Development of Structural Pile Foundations in Japan During the Meiji Era 1868–1912

Modern technology including pile foundation engineering in Japan developed after the opening of the country brought about by the Meiji Restoration of 1868 under the influence of Western technology. In this paper the development of the early pile foundation engineering has been clarified and examined, covering from conventional wood piles to iron piles through major construction projects in the Meiji era. The development of pile foundation technology was driven by the construction of railways, bridges and port facilities such as jetties and piers that played an important role in the modernization of infrastructures in the Meiji era.

Pheromone Components in the Larch Bark Beetle, Ips cembrae, from China: Quantitative Variation among Attack Phases and Individuals

Ips cembrae adults were collected from larch log piles in northeast China, separated into six attack phases, and immediately frozen in liquid nitrogen. Three previously described aggregation pheromone components [ipsenol, ipsdienol, and 3-methyl-3-buten-1-ol (331-MB)] and six other volatiles of beetle origin (2-phenylethanol, geraniol, ipsenone, ipsdienone, myrtenol and verbenone) were identified and quantified by GC-MS from excised male hindguts. No amitinol, a recently reported aggregation pheromone component, was detected in our samples. The amounts of these volatiles (except the last two) showed a similar pattern of variation between attack phases in males. The largest amounts of most male volatiles were present in phases 1–2, when the nuptial chamber was being constructed or only one female was accepted. The amounts of the volatiles declined sharply in the following phases. The hindgut volatiles, mainly the pheromone components, from 46 individual males in phase 1 were also quantified. Ipsenol, ipsdienol, and 331-MB showed a large variation in both amounts and proportions. The chirality of these two dominant aggregation pheromone components was determined as 100% (−)-enantiomer of ipsenol and 96% (+) enantiomer of ipsdienol. No male aggregation pheromone components were detected from mated females, except three extracts that were probably contaminated by male tissues.

Wave speed: The key to insitu wooden pile length assessment

A ruggedized field measurement system for determining wood pile lengths of existing bridges is presented. The development of the measuring system was the goal of a two year funded research project sponsored by the Tennessee Department of Transportation. The measurement technique is based on longitudinal vibration theory. Determination of the wave speed in the wood and the resonant frequencies of a pile will yield the length estimation. The equipment package uses piezoelectric actuators, random excitation, and force and accelerometer transducer responses to generate the required data for length assessment. The data acquisition and processing occur in the field and are controlled by a LabWindows/CVI custom program. An electronic pulse and special signal conditioning are used for determining accurate delay time between accelerometer locations for the wave speed calculation. Random excitation is used to generate the power spectral densities and frequency response functions of the transducers attached to the pile. Typical field data will be discussed along with the results from preliminary field tests.