Modern timber bridges are readily available, relatively easy to design and fabricate, practical, and cost effective alternatives for small roadway bridge construction as well as in certain types of highway bridge situations. Stresslaminating is the newest development in timber bridge construction and offers many advantages over conventional naillaminated lumber systems. Conform to astm d2559 bond is stronger than wood efficient use of resource concepts of modern timber bridges use of gluedlaminated timbers. Timber as a bridge building material is not durable unless it is. Contrary to popular belief, large wood members provide good fire resistance qualities that meet or exceed those of other materials in severe fire. A level 2 or 3 inspections has determined a timber girder to be in condition state 4, with a major. Modern timber bridges laminations are dried before gluing, reducing seasoning effects.
Modern timber bridges concepts of modern timber bridges use of gluedlaminated timbers. Timber as a bridge material minnesota department of. Design, construction, inspection, and maintenance, u. Development and integration of advanced timber bridge inspection. Preservation and protection of timber bridges pdf chapter 5. Many timber bridges built in the 1950s and 1960s are approaching the end of their projected service life. May 10, 2020 theory and design of bridges theory of bridge aerodynamics timber bridges design, construction, inspection, and maintenance truss bridge analysis truck weights urban flyovers structure, architecture, sustainability use of fiber reinforced polymers in bridge comstruction wind effects on cablesupported bridges wind resistant design of bridges. Wood is one of the most durable bridge materials, but over extended. Design, construction, inspection, and maintenance michael ritter in this comprehensive classic manual, the author describes the use of timber as bridge material, types of timber bridges, the properties of wood and wood products, preservation and protection of timber bridges. State highway departments in many states have programs to specify modern timber bridges in appropriate highway situations. Decay is the most serious timber defect and is the reason for most timber bridge maintenance needs. The new generation of timber bridges fachhochschule erfurt. Combining the advances in wood design, the use of gluedlaminated timber, stresslaminated deck, and preservative treatment, permits wooden bridges that are economical, easy to construct, and which have a long service life. Modern timber bridges design codes and specifications vehicular bridges modern timber bridges.
A brief description of each longitudinal deck bridge type is provided in timber bridges. When timber properties are not provided on the original plans and cannot be determined from any other source i. Samhallsbyggnad byggteknik durable timber bridges final. It presents recent developments and evolving concepts in timber bridge technology, including aspects concerning wood material, bridge design, construction, inspection, rat ing, and maintenance. Timber bridge maintenance manual department of transport. Post tensioning rod standard timber superstructure header. Timber bridges forest products laboratory forest service. Bridge inspection standards nbis, implemented in 1971, prescribe minimum requirements for the inspection of highway bridges in the united states. Section 2 covers the design, construction and maintenance of all timber bridge substructure systems and specified components as outlined in subsection 2. Montana local technical assistance program publications list. Timber bridges design, construction, inspection, and maintenance case history 15.
Properties of wood and structural wood products pdf chapter 4. Timber bridges design, construction, inspection, and maintenance michael a. One such prehistoric bridge, used by the gauls in the hills of savor in italy, was viewed by julius caesar, who described it as follows. Timber bridges design, construction, inspection and maintenance. Design and construction of bridges consisting of the natural building. Requirements for the design of wood decks and deck systems are described in the lrfd specifications, article 9. In doing this it works towards the goals of 1 educating all engineers and educators of. Timber s strength, light weight, and energyabsorbing properties furnish features desirable for bridge construction. Timber bridges are well suited for short and mediumspan applications to carry vehicle or pedestrian traffic fig. Timber bridges, design, construction, inspection and maintanance. Timber bridges forest products laboratory usda forest service. When construction is complete we will schedule a final walkthrough of your vehicular timber bridges.
Rehabilitation design section of bridge engineering branch for clarification. Lower construction cost may be achieved with timber constructions. This chapter describes general guidance in the design of a wood superstructure. Bridge engineering books codes, manuals, specification for.
This section is to be read in conjunction with section 1 general and other. Design, construction, inspection, and maintenanceengineering staff 1997 this document provides engineers and educators with stateof the art information on timber bridges. The chapter on timber connections provides a comprehensive discussion of covered bridge joinery and represents an important contribution to covered bridge engineering. A useful reference book, timber bridges, design, construction, inspection and maintenance, is listed at the end of sections 8 and 9. See asce manuals and reports on engineering practice no. Design, construction, inspection, and maintenance, 1990. Pdf introduction to timber as an engineering material. Pdf wood protection by design concepts for durable timber. Some of these bridges can be left as they are for the present time, some should be upgraded, and some will need to be replaced. Typical dimensions for timber connectors continued. Sweden has obtained from inspections of timber bridges for bridge owners. Design, construction, inspection, and maintenance 9. Jul 01, 20 timber s strength, light weight, and energyabsorbing properties furnish features desirable for bridge construction. Timber bridge manual edition 1 r 0 section 4 page 1 of 50 4.
Such features are desirable in bridge construction. In this comprehensive classic manual, the author describes the use of timber as bridge material, types of timber bridges, the properties of wood and wood products, preservation and protection of timber bridges, timber design concepts for bridges, loads and forces on timber bridges, design of beam superstructures, design of longitudinal deck superstructures, design of longitudinal stress. The bridge deck is not designed to carry the vehicular loads. Background information about timber technology and design, alternative materialssystems, timber preservation practices and inspection requirements for timber bridges. This report presents a comprehensive analysis of the design, construction, inspection, and maintenance of timber bridges. Timber a new zealandwide survey of bridges found that timber components consistently showed the highest percentage of defects. Timber by itself is quite strong and at the same time lightweight material. Timber bridges must be periodically maintained or rehabilitated in order to keep them in a condition that will give optimum. Post tensioning timber bridges amazon web services. Railing systems for longitudinal timber deck bridges. Timber bridges design, construction, inspection and maintenanceaugust 1992 manual published by the united states department of agriculture, forest service is an excellent reference to supplement timber information in this manual.
In addition, weather does not affect the construction process so much, there is no dan. Design, construction, inspection, and maintenance s chapter 16. Basic timber design concepts for bridges pdf chapter 6. Em 77008 by forest service free pdf d0wnl0ad, audio books, books to read, good books to read, cheap books, good books, online books, books. In each system, the lumber laminations are placed edgewise and oriented with the lumber length parallel to the direction of traffic. Durable, lowmaintenance and competitive bridges could. An overview of timber bridges transportation research board. The federal highway administration fhwa asked the south dakota local transportation assistance program sd ltap to put together a new gravel road manual that can be used. The design of wood structures shall be in accordance with aashto and usda united states department of agriculture forest service timber bridges, design, construction, inspection, and maintenance. Timber bridge maintenance manual transport and main roads. Wood protection by design concepts for durable timber bridges.
Timber bridge maintenance manual department of transport and. Ritter, structural engineer united states department of agriculture. Swedish timber bridges because of different construction techniques and materials. Compared to other materials, wood can be more economical. The first 15 chapters cover the following topics, respectively. Timber bridges design, construction, inspection, and maintenance. Timber bridges design, construction, inspection and. As an example of our commitment to the highest standards, bridge builders schedule a mutual inspection of your site within one year after completion. Laminated timber bridge has many timber a new zealandwide survey of bridges found that timber components consistently showed the highest percentage of defects. You will walk through all of the completed bridges to ensure your complete satisfaction. Key words covered, bridge, manual, design, construction, rehabilitation, historic, preservation 18.
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