Abstract: In this brief, the investigational results for a robust adaptive vibration control of a translating tensioned beam with a varying traveling speed are presented. The dynamics of beam and actuator is modeled via the extended Hamilton's principle, in which the tension applied to the beam is given as a nonlinear spatiotemporally varying function. The moving beam is divided into two parts, a controlled span and an uncontrolled span, by a hydraulic touch-roll actuator that is located in the middle section of the beam. The transverse vibration of the controlled span is suppressed by the touch-roll actuator, whereas the vibration of the uncontrolled span is treated as a disturbance, and the magnitude of unknown disturbance is estimated. In a proper mathematical manner, the Lyapunov method is employed to design robust adaptive boundary control laws for ensuring the vibration reduction of the nonlinear time-varying system, and also to ensure the stability of the closed-loop system. The effectiveness of the proposed controller is demonstrated via numerical simulations.

Abstract: Recently, there has been a rapid increase in using noncorrosive fiber-reinforced polymers (FRP) reinforcing bars as alternative reinforcement for bridge deck slabs, especially those in harsh environments. A new two-span girder type bridge, Cookshire-Eaton Bridge (located in the municipality of Cookshire, Quebec, Canada), was constructed with a total length of 52.08 m over two equal spans. The deck was a 200-mm-thick concrete slab continuous over four spans of 2.70 m between girders with an overhang of 1.40 m on each side. One full span of the bridge was totally reinforced using glass fiber-reinforced polymer (GFRP) bars, while the other span was reinforced with galvanized steel bars. The bridge deck was well instrumented at critical locations for internal temperature and strain data collection using fiber optic sensors. The bridge was tested for service performance using calibrated truckloads as specified by the Canadian Highway Bridge Design Code. The construction procedure and field test results under actual service conditions revealed that GFRP rebar provides very competitive performance in comparison to steel.

Abstract: The problem of finding the length of a shortest feedback shift register that generates a given finite-length sequence is considered. An efficient algorithm for the determination of the span is proposed, that takes advantage of the special block structure of the associated system of linear equations. The span distribution of finite-length binary sequences is also studied.

Abstract: A system and method for pressure measurement may include the ability to readily produce a pressure measurement system. In one general aspect, pressure measurement 100 may include a signal-converting circuit 500 that includes a coupler 510, a signal biaser 550, and a signal span adjuster 560. The coupler is operable to receive a pressure-representative signal, and the signal biaser includes a thermally-insensitive voltage divider that facilitates biasing the pressure-representative signal. The signal span adjuster is coupled to the coupler and the signal biaser and includes a thermally-insensitive voltage divider that facilitates adjusting the span of the pressure-representative signal.

Abstract: The way in which a new road bridge made from Super Cor steel plates was tested is described and the test results for three static load schemes in which one ballasting vehicle (a Scania truck) was used as the load are presented. The tested bridge has a box structure and it is located on the Giman River in Giman, Sweden on the Bracke-Holm road. The bridge has an effective span of 12.315 m and a clear height of 3.555 m . The span’s steel shell is founded on two reinforced concrete continuous footings. The average measured displacements and strains (normal stresses) in selected points and elements of the steel shell structure were found to be much smaller than the ones calculated for the same load. The conclusions drawn from this research can be useful for assessing the performance of such steel shells and their interaction with the surrounding backfill. Since such steel–soil designs are used more and more often for small and medium-sized bridges on road and railway lines in Poland and in the world, the concl...

Abstract: For estimating the vortex excited vibrations of overhead transmission lines, the Energy Balance Principle (EBP) is well established for spans damped near the ends. Although it involves radical simplifications, the method is known to give useful estimates of the maximum vibration levels. For very long spans, there often is the need for a large number of in-span fittings, such as in-span Stockbridge dampers, aircraft warning spheres etc. This adds complexity to the problem and makes the energy balance principle in its original form unsuitable. In this paper, a modified version of EBP is described taking into account in-span damping and in particular also aircraft warning spheres. In the first step the complex transcendental eigenvalue problem is solved for the conductor with in-span fittings. With the thus determined complex eigenvalues and eigenfunctions a modified energy balance principle is then used for scaling the amplitudes of vibrations at each resonance frequency. Bending strains are then estimated at the critical points of the conductor. The approach has been used by the authors for studying the influence of in-span Stockbridge dampers and aircraft warning spheres; and for optimizing their positions in the span. The modeling of the aircraft warning sphere is also described in some detail.

Abstract: The design and construction is described of a vehicle bridge made of glass-reinforced polyester pultruded box beams. The bridge has a simply supported span 11·6 m long and 4 m wide. It has been designed as a Class 30 (300 kN load capacity) according to DIN 1072 and represents a single traffic lane. The composite bridge consists of a 3-D truss structure made of thick-wall fibre-reinforced plastic longitudinal box elements of hollow square cross-section. The bridge design proposed allows for fast construction as it consists of pre-fabricated, ready to assemble elements. The total of the composite bridge does not exceed 135 kN.

Abstract: A system for setting a span load distribution of a wing of an aircraft with a base flap system comprises at least one inboard flap element and one outboard flap element, which elements in the direction of the span are arranged on the trailing edge of the wing, and can be positioned relative to the span direction of the wing. The flap elements are not mechanically coupled with each other and are controlled independently of each other for the purpose of setting the span load distribution.

Abstract: A series of horizontally curved bridges were analyzed using simple finite-element models. The analyses included using a typical truckload and also the dead load as the primary forces on bridges. In each analysis, the behavior of bridges was investigated, and the major internal forces developed in members were determined. Specifically, an increase in bending moment and the existence of a torsional moment in cases where the horizontal angle of curvature is large (about 20–30°) was observed. The significance of these moments, compared with the maximum bending moment of a comparable straight bridge, was noted. Bridges used in the analysis were assumed to be composed of single spans with about 30.5-m (100-ft) span lengths (the chord length was set at 30.5-m for all bridges), steel girders, and an 203-mm (8-in.) reinforced concrete slab. The finite-element analyses consisted of a three-dimensional idealization using simple beam elements to model top and bottom flanges of the girders and plate bending elements m...

Abstract: A new highway system is being constructed in Chile including many bridges. Due to the high seismic risk in the country, high damping rubber bearings, friction bearings, and passive energy dissipation devices have been considered in the design of the majority of the new moderate and large span bridges. Their design follows American Association of State Highway guidelines and technical specifications from the Chilean Ministry of Public Works. Experimental and analytical studies have been performed in three of these structures: (1) a 383 m long continuous beam bridge supported on high damping rubber bearings; (2) a 268 m long continuous beam bridge supported on friction bearing with additional viscous dampers; and (3) a five-span simply supported beam bridge resting on neoprene bearings. Predominant periods and damping characteristics for small amplitude vibrations have been determined from output-only nonparametric analyses. Comparison with standard analytical structural models indicates that the models normally used for analysis yield comparable predominant periods and mode shapes but the damping values typically recommended are larger than the ones observed from ambient vibrations, even when additional energy dissipation elements are present.

Abstract: This paper presents a de-icing device, called DAC (De- icer Actuated by Cartridge), which aims at de-icing overhead ground wires, span by span. This is a mechanical method which consists of using a portable cylinder-piston system that creates shock waves to de-ice the cable. Since linemen cannot climb ice- covered towers, the de-icing operation is carried out entirely from the ground. First, a commercially available line-thrower is used to throw a projectile which tows a line that passes over the cable to be de-iced. Next, the DAC is pulled up to the cable and held in place by a taut rope. The DAC is equipped with a revolver barrel that stocks 6 blank cartridges that can be remotely fired from the ground. Numerous tests have been carried out to assess the efficiency of the method and to optimize the physical parameters of the device.

Abstract: Span programs provide a linear algebraic model of computation. Monotone span programs (MSP) correspond to linear secret sharing schemes. This paper studies the properties of monotone span programs related to their size. Using the results of van Dijk (connecting codes and MSPs) and a construction for a dual monotone span program proposed by Cramer and Fehr we prove a non-trivial upper bound for the size of monotone span programs. By combining the concept of critical families with the dual monotone span program construction of Cramer and Fehr we improve the known lower bound with a constant factor, showing that the lower bound for the size of monotone span programs should be approximately twice as large. Finally, we extend the result of van Dijk showing that for any MSP there exists a dual MSP such that the corresponding codes are dual.

Abstract: This paper presents issues in the design concept, analysis, and test results of a harp-shaped single span cable-stayed bridge, Hongshan Bridge, located in Changsha, Hunan Province, China. The bridge has a 206 m span, with a pylon inclined at 58° from the horizontal and 13 pairs of parallel cable stays without a back stay. This paper discusses the design approach for the main components of the bridge. Emphasis will be put on the following three aspects. First, the weight of the pylon and all dead loads of the main girder in addition to part of the live loads must be in a balanced condition. Second, the main girder should be an orthotropic steel-concrete composite box girder because of the superior safety and weight reduction of this type of structure. Third, the cable stays should be anchored at the neutral axis of the pylon to prevent the development of high secondary moments caused by other anchor approaches. Furthermore, based on results from tests carried out on three models, namely, scaled full model ...

Abstract: PROBLEM TO BE SOLVED: To provide a bridge capable of having excellence in wind-resistance efficiency and obtaining a super-huge bridge having a huge center span (3,000 m class) which has not been erected hitherto. SOLUTION: The bridge 1 has a plurality of main towers 2 and 2 installed at an interval and a bridge girder 3 forming parts stretched to both sides through the main towers 2 and 2 in one box girder 31, and, forming the center between both towers in two box girders 32, and is so constituted that the bridge girder 3 in the vicinity of the main towers 2 is supported by a plurality of diagonal tensile cables 4 fixing each one end of them to the main towers and that the center is supported by a plurality of hanger ropes 5a, etc. suspended from two main cables 5 and 5 stretched through the tower tops 2a of the main towers. Each lower end of the hanger ropes 5a, etc. is connected to the outside edge 3a of the bridge girder of the main cable side suspending the hanger ropes 5a. COPYRIGHT: (C)2007,JPO&INPIT

Abstract: The way in which a new road bridge made of steel corrugated plates Super Cor type was tested during the three stages of its construction is described and the test results are presented. Backfill in construction Stage I and two ballasting vehicles in Stages II and III constituted the loads. The box bridge spans the Bystrzyca Dusznicka River in Polanica Zdroj, Poland. The span’s effective length is 12.27 m and its vertical inside diameter is 3.85 m . The steel span is founded on two reinforced concrete strip foundations. The average values of the displacements and strains (normal stresses) measured in selected points and on selected elements of the steel shell structure were much smaller than the ones computed for the same load. The conclusions drawn from this research can be helpful in determining the interaction between the steel shell and the backfill. Since this type of steel–soil structure is increasingly used in Poland and in the world, the conclusions can be generalized to a whole class of similar br...

Abstract: The present invention relates to lower leading-in girder type bridge span erecting machine and its bridge span erecting method, and relates to transporting and erecting equipment and method for bridge in railway, highway and city. The bridge span erecting machine consists of girder raising machine, lower leading-in girder and tyre type girder transporting carriage. The girder raising machine includes main structure, lifting mechanism and the longitudinal moving overhead traveling crane; and the girder transporting carriage includes roller box assembly. During erecting bridge span with the bridge span erecting machine of the present invention, the interaction between the middle outrigger and the back outrigger and the fixed point hoisting mode are adopted.

Abstract: A span wire assembly for supporting a traffic control device. The span wire assembly includes a pair of vertical members or cast arms for attachment to the traffic control device. The cast arms are integrally formed with tubular ends and a centrally positioned wiring passage. A span wire assembly utilizing the inventive cast arms has fewer parts and, consequently, is simpler for the manufacturer to produce and for the customer to use.

Abstract: This paper describes an effort to develop a global dynamic testing technique for evaluating the overall stiffness of timber bridge superstructures. A forced vibration method was used to measure the natural frequency of single-span timber bridges in the laboratory and field. An analytical model based on simple beam theory was proposed to represent the relationship between the first bending mode frequency and bridge stiffness (characterized as EI product). The results indicated that the forced vibration method has potential for quickly assessing the stiffness of the timber bridge superstructure. However, improvements must be made in the measurement system to correctly identify the first bending mode frequency in bridges in the field. The beam theory model was found to fit the physics of the superstructure of single-span timber bridges and could be used to correlate first bending frequency to global stiffness if appropriate system parameters are identified.

Abstract: This invention relates to a side span closure method for a continuous rigid bridge without down-to-the-ground frames including selecting a ratio of side span/middle span in the sphere of 054-056, laying out and designing sections in terms of the river course hydrogeological condition, designing and analyzing it to select suitable sections to arrange ordinary steel bars and prestressed bars and drafting a construction pattern, symmetrically casting in terms of each T, selecting one way to finish side span closure: A the side span site-cast handing basket is extended and moves forward, the other end is supported on a side pier, utilizing the suspending arm and the side pier to bear the basket to site cast the closure section, B removing the basket and matching the truss beam on the beam and side pier an hanging forms

Abstract: Three-dimensional nonlinear aerodynamic stability analysis was applied to study the aerodynamic stability of a cable-stayed-suspension (CSS) hybrid bridge with main span of 1400 meters, and the effects of some design parameters (such as the cable sag, length of suspension portion, cable plane arrangement, subsidiary piers in side spans, the deck form, etc.) on the aerodynamic stability of the bridge are analytically investigated. The key design parameters, which significantly influence the aerodynamic stability of CSS hybrid bridges, are pointed out, and based on the wind stability the favorable structural system of CSS hybrid bridges is discussed.

Abstract: The invention discloses a method for identifying hauling gesture generating on a touching-control device , whose characteristics includes that the time span of a subject appears on for the first time, time span of the finishing time of the first appearance and starting time of the second appearance, when the summation of the two above is shorter than the first reference time value, and if the summation of the time span of the first appearance, the time span between the first and second appearance and the time span of the second appearance is not shorter than the first reference time value, or the accumulated displacement value during the second appearance is not shorter than the first reference displacement value, a ignal of hauling is generated.