The failure of several pony truss bridges at the end of the nineteenth century prompted the. In a deck truss bridge the road is above the trusses and the deck system is on the top chords. The second was a survey of other transportation agencies to document current trends in truss bridge. Great american bridges and dams new york, et al john whiley and sons, 1988, p. Evaluation of one hundred and one instrumented bridges. Due to modern construction practices, and increased costs, new truss connections will be bolted or welded gusset plates rather than antiquated pinned connections. Pinconnected warren truss bridges like this bridge are very rare both in michigan and nationwide. The superstructure of this bridge is a warren pony truss span. Figure 2 shows the schematic of the suspended span, which is from member lu to l21u21. Simple span steel through truss bridge virginia department of. Stored truss inventory vermont agency of transportation. A pony truss bridge is the same as a through truss, but it does not have lateral bracing between the top chords.
Cablestayed bridge suspension bridge truss bridge bridge type posters arch bridges beam bridges cablestayed bridges suspension bridges truss bridges curriculum page number the bridge basics program kithas been produced in partnership with the construction industry round table cirt. Pdf extending the lifetime of steel truss bridges by costefficient. Truss type the battle creek king post truss bridge is a single span, riveted pony truss that measures 38 feet in length and 16 feet in width. Sand creek camelback pony truss nash vicinity oklahoma. The superstructure of a truss bridge usually consists of two parallel. Ha1251 bridge sha h94, iron truss bridge, cherry hill. These include the pratt, warren, camelback, and parker trusses, as well as plate girders and their varients.
The bridge contains few alterations and remains a good example of a steel truss bridge. A thesis submitted to the faculty of the of the graduate. The chords and members of a truss bridge experience strain in the form of tension stretching apart and compression squeezing together. A study by the historic american engineering record pdf. The width measurement from centerline of the east upstream truss to centerline of the west downstream truss is 27 feet, one inch. Rehabilitation of a steel pony truss using maintenance free. Built circa 1890the queen anne bridge is the only surviving example in prince georges county of a pratt pony truss bridge constructed of phoenix sections. It crosses the musconetcong river between lebanon township, hunterdon county and washington township, warren county. The new hampton pony pratt truss bridge is a historic pony pratt truss bridge on shoddy mill road in new hampton, lebanon township, hunterdon county, new jersey.
The first involved a literature search and cataloging of relevant information. Investigation of prefabricated steeltruss bridge deck system. The bridge is located in rural southwestern crow wing county. The bridge is a noteworthy example of the states then newlyformulated pinrigid connection technology. Historic bridge inventory form highways through history. Option 2 new 1lane steel pony truss a new prefabricated steel pony truss superstructure with integral walkway will replace the existing truss bridge.
Minnesota departmen t of transportatio n mndot local. It replaced earlier bridges the first built in 1757 that had been built to connect the busy port of queen anne town to anne arundel county. Truss girder form refers to the type of truss used for the bridge. Eden bridge press release pdf eden bridge information packet pdf for more information contact. Floor beam, vertical members and diagonal members of a pony truss bridge halfthrough. It is minnesotas most notable example of a pre1925, standardplan, warren pony truss bridge designed by the minnesota highway department. The pratt truss the pratt truss was first developed in 1844 under.
Built in 1918, bridge 2110 is eligible for the national register of historic places. One of the major hindrance in efficient transportation are deep valleys and rivers. To complete the first task of the project three steps were taken, which are described in this paper. Learning objectives as a result of this learning activity, you will be able to do the following.
Zafar anwar april,2016 motivation the very basic pillar of modern civilization is efficient transport system. Types of truss bridges are also identified by the terms deck, pony and through which describe the placement of the travel surface in relation to the superstructure see drawings. Dry creek pratt half hip pony truss bridge spanning. To a lesser extent, it was also found that truss members in properly designed and constructed bridges can also be.
Bridge l3942 is a steel, threepanel, halfhip, pratt pony truss resting on concrete abutments with flared wingwalls. It is no longer in service, but it previously carried a minimummaintenance road over the nokasippi river. Whiteoak bridge boone county highways through history. Overview of the activity in this learning activity, we will design, build, and test a model truss bridge.
A pony truss is a truss bridge which has no bracing over the top of the roadway. Bridge types were defined as pony, thru, and deck trusses and were further broken down into designs. Truss bridges can have any of the 3 span types including simple, continuous, or cantilever. This single span pratt pony truss bridge is a good example of early 20th metal bridge construction. Maryland examples discovered through research may include a group of bridges built in the 1920s and early 1930s under the aegis of the state roads commission. Show pictures to the class of different bridge types and discuss the strengths and weaknesses of each. Also note whether each bridge is a through truss, deck truss, or pony truss. D all structures for which there are fewer than 18 known extant examples of. The sand creek camelback pony truss bridge, built in 1936, is a rare example of a sixpanel, camelback pony truss bridge in north central oklahoma. Key terms to successfully complete this learning activity, you must understand the following key terms and concepts from previous learning activities. The 80foot trusses are minnesotas longest surviving examples of this particular truss type. It is the longest bridge in the baltimore metropolitan area and is 1,200 meters long. If the truss system is located entirely beneath the deck, the bridge is called a deck truss.
Pdf stress analysis of trusses bridges zafar anwar and. Originally known as the outer harbor crossing, the francis scott key bridge was first opened in 1977. Counter diagonal braces camelback truss parker bridge. Multispan pony truss bridges are uncommon, and this fourspan structure is the longest remaining pony truss in michigan. Cheat bridge is eligible for the national register under criterion a for association with the development of us route 250, a major eastwest transportation route. The dry creek bridge is an unusual example of a small bridge constructed by the missouri valley bridge and iron company, known for its work on large railroad and highway bridges across the southwest.
Each individually meets criteria for listing in the national register of historic places. Certain metal truss and plate girder bridges can be determined as significant without much ado. Description of example truss bridge t5 truss enhancements suspended truss bridge. Coltman bridge, spanning fever river, on horseshoe bend. An example of a lenticular pony truss bridge that uses regular spans of iron is the turnofriver bridge designed and manufactured by the berlin iron bridge co the pauli truss is a variant of the lenticular truss, with the top chord carefully shaped so that it has a constant force along the entire length of the truss. Rollins farm bridge is an overhead timber boxed pony truss bridge spanning 358. Maadi group aluminum pedestrian bridge catalog maadi.
Girder bridges for arrc pony truss replacement response required this form must be completed and returned to ensure receipt of future addenda or additional information. The majority of marylands surviving metal truss bridges are pratt through and pony trusses, including both pinconnected and riveted examples. I had heard the term before, but never understood what it meant. No overhead bracing structural stability 28 pony truss bridge buckling by ansys. Most truss bridges are designed for a safety factor greater than 1. Additionally, the kilgore bridge is one of the few remaining multiplespan pinned pony trusses in nebraska. All addenda will be forwarded to the contract name and number listed below. The bridge consists of a 110foot simple span rivet connected pony truss camelback warren supported on concrete abutments.
Starting in 1920 the state highway department adopted the steel riveted parker truss as its standard pony truss design, with plans provided for trusses of 100,110, and 120 feet. It is believed that the hemlock road bridge is an example of a michigan standard pony truss bridge. Once constructed of wooden timbers, and later including iron tension members, most truss bridges are built of metal. Dry creek pratt half hip pony truss bridge spanning dry creek. Active project based learning in structural analysis. Fracture critical analysis procedures and design and retrofit. The bowstring pony truss is the only identified example of a wrought iron bridge company pony truss to exist in this state. It was listed as grace bridge on the 1990 final list of historic bridges for west virginia.
Cited in local newspapers as nearly a hundred years old this bridge, with a presumed ca. The main street parker pony truss bridge was built in 1904 by huston and cleveland of columbus, ohio. Pony truss idealized as a continuous beam on spring support figure 14. A pony truss looks just like a through truss, except it is not as high and has no lateral bracing between the top chords. Truss bridges may be built as simple spans, with abutments or piers at either end, or as continuous spans, with intermediate piers, bents or columns supporting the superstructure. Although the firm only operated from 19021907, it built quite a few bridges in the mahoning county area, of which this is a good example. Preservation alternatives for historic metal truss bridges. A truss bridge is a bridge whose loadbearing superstructure is composed of a truss, a structure. Pdf steel truss bridges are an efficient and aesthetic option for. The cloud creek bridge is a singlespan warren with polygonal top chord pony truss that is 80 feet long and 14. Stresses in the bridge deck with two trucks are on the bridge.
Edwards sheet metal works of frederickton, ohio despite potential for less costly rehabilitation, demolition and replacement was selected for this bridge. Bridge l4005 is significant as the earliest and longest surviving halfhip pratt pony truss built by the joliet bridge and iron company in minnesota. The county hopes the old bridge can be reused in a park, trail system, or similar setting. All vertical truss members shall be perpendicular to the ground horizon after the bridge is erected and dead loads applied. The main objection to pony truss bridges is that no. It was built by the indiana bridge company and highly rated in a survey of indianas metal bridges. Ifportal bracing connects the trusses, the span is a through truss. We will develop a truss configuration, analyze the struc.
Distance from the left edge of deck to superstructure definition reference line. Example of detail category c for longitudinally loaded bottom. Government invest a large part of its budget over the development of these infrastructures. The combination bowstringcamelback bridge is a riveted steel high through truss and is one of only five camelbacks known to exist in the state. The timber truss bridges were part of the original truss survey, including both metal and timber structures, and the concrete truss.
Wooden and metal truss bridges 263 survey report for historic highway bridges increased, and it greatly impacted metal truss bridge design. In the specific case of steel truss bridges, a reasonable method to extend the. Stress analysis of trusses bridges abhishek arunachalam apoorva pradhan md. The 1879 construction date makes this one of the oldest truss bridges in michigan.
Large truss are constructed by attaching several triangles together a new triangle can be added truss by adding two members and a joint. The truss span is 90 feet long, measured from center to center of the truss end bearing pins. There were some longer howe truss bridges that were built during the 1850s and 60s. Steel bridge design had not been standardized each bridge was an original design that requires time and money, whereas concrete bridges are standardized designs the sssba developed standard simplespan and modular designs espan140 short span steel bridge design.
Cheat bridge carries us route 250 over shavers fork in. Rehabilitation of a steel pony truss using maintenance. Main street parker pony truss bridge, main street route 170. Teacher information truss bridge 2 a measure of the load a structure can withstand beyond the load for which it was designed. Historic, standard, boxform concrete abutments support the end floor beams of the truss, which rest directly on the abutment seat. Structural research section of the ontario ministry of transportation and communications on a pony truss bridge in 1969. Fracture critical analysis procedures and design and. Its loadbearing elements consist of three parallel modifiedhowe trusses, each of. A halfthrough truss, or pony truss, has a deck at the level of the bottom chord, but does not include bracing along the top of the structure. A pony truss is a truss bridge which allows traffic through the truss, but the top of the bridge is not joined together with cross braces. Evaluation and rehabilitation of historic metal truss bridges. Since there are several hundred pony truss bridges in ontario alone, it is economically important to determine the extent to which these bridges can usefully serve their purpose. Methodology for 2017 metal truss bridge reevaluation. The pratt truss and its derivations became the most popular metal truss in the united states by the early twentieth century.
A truss bridge is one form that a bridge can take and there are at least 30 different kinds of truss bridges, including the warren, pratt, and howe designs among others. Figure 1 shows the schematic of the example truss bridge. Bridge l4005 is a rivetedbolted steel pratt pony truss with timber deck. That makes it the thirdlargest truss bridge in the world. We will analyze the owners needs, then formulate specific design requirements. When the roadbed is atop the truss it is called a deck truss an example of this was the i35w mississippi river bridge. For a standard bridge span length of 165 feet, he determined the howe trusses needs 54% more iron in the web and the pratt needs 31% more iron than the isometrical truss. Overview of the activity in this learning activity, we will use a specially developed software package called the west point bridge designer to design a truss bridge. For example, in the 2001 inventory those bridges with minor alterations were determined. College street bridge is a fourspan, steel, tr uss structure which crosses the barren river in bowling green, kentucky see figures 1 and 2. It is a notable example of a pratt with half hip pony truss bridge, a modified form of a. The bridge is also a works progress administration wpa bridge that. Spans 1 through 3 are through trusses, and span 4 is a pony truss.
Engineers often picked different types of materials and designs for the different parts of a bridge based on these forces. Macdonald concluded the only cost savings in a truss bridge are in the web members, as the top and bottom chord requirements were the same for most bridges. Guidelines for assessing the cultural significance of. Pony trusses have the same failure modes as a through or deck truss, but also require additional design.
Most bridges of this design type have five panels per span. The bridge has lost integrity of a number of its character defining elements with the introduction of the 1991 loadcarrying steel pony truss. It crosses guilford transportations portland division main line, on a northwestsoutheast axis, with a clearance of 2112 and a slight skew. The historic bridge was built in 1915 and presently serves as a pedestrian bridge. It was built by fort pitt bridge works, founded in 1896 and was. The spans are between 15m to 30m 50ft to iooft, with the deck generally made of concrete.
It was built in 1868 by william cowin of lambertville, new jersey. Virginia transportation and research council, may, 1975, p. One is the bridge and the other two are the tunnels. The typical new truss is assumed to be a warrentype or pratttype pony truss with vertical truss web members at each panel point.
These are bridges in truss made of steel with parallel cord or superior curved cord. Pdf investigation of prefabricated steel truss bridge and deck. Key periods of significance for metal truss bridges in maryland, as indicated. The eden bridge is significant as the states longest surviving example of a warren pony truss that used the widely adopted 19171925 minnesota highway departments standard plan. One of only two mid20th century riveted pony truss bridges documented in morrow county. The bridgehas been significantly altered presumably due to deterioration concerns regarding the steel truss members. The top chord truss members and the vertical truss. Erected by the state in the late 1920s, the bridge replaced a ferry. The study of eigenfrequencies is important with respect to the excitation and. Population loss numbers were examined to understand rarity across the state and. Bowstring truss bridge bridge widening retrofit multiple single spans up to 30. It is minnesotas most important surviving example of a pre1925, standardplan, warren pony truss bridge designed by the minnesota highway department.
If the deck is located at the level of the top chord, the bridge is called a deck truss. It was found that when they are properly detailed and constructed, deck systems in pony truss bridge can be inherently redundant. A truss constructed in this fashion is known as a simple truss. Aug 17, 2017 today i found out what exactly a pony truss is. Truss bridge status report vermont agency of transportation. Does the bridge retain integrity of important elements described in context addendum. Wooden truss bridges provided a means to span large crossings efficiently. In a deck truss bridge the road is above the trusses and the deck system is. Historic bridge needs new home minnesota department of. A cantilevered truss bridge consists of anchor arms supported by piers, and a. This bridge is a somewhat compromised example of a pratt through truss. We will use the software to create a structural model, then run a simulated load test to evaluate the design. Out of 443 wisconsin trusses of this design, this bridge is one of three of the best examples. Collectively, they illustrate the range of dates of construction, methods of construction, and uses to which truss bridges have been put in more than a century of california history.
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