Civil engineering spreadsheet software downloads cesdb. Girder concrete strength can be used if intermediate diaphragm is confined. Fixed problem applying end diaphragm load to cantilevered girders fixed problem modeling cantilevered girders fixed problem with sidewalk display in bridge section view when the entire bridge is located on one side of the bridge line fixed problem computing bearing seat elevations for multibearing supports with rotated girders. West point bridge designer provides you with the tools to model, test, and optimize a steel highway bridge. Bridge seat size should accommodate the new bearing size, side retainers if required, side clearances for the bearing and anchor bolts, and the minimum seismic support length. The intent is to provide guidance as well as an interpretation of aashto lrfd bridge design specifications specific to new mexico bridge design. The designer should therefore consult widely at an early stage in the initial design. The crossframe forces for the final fit detailing method at the steel dead load. A single pair of brbs is installed at each end of a span, at an angle that does not coincide with the bridge longitudinal and skew directions fig. In fact, it doubles their number because, in addition.
Department of transportation federal high way administration bracing system design. Seismic retrofitting of bridge abutments methods and details. A horizontal diaphragm element parallel and in line with the applied force that collects and transfers diaphragm shear forces to the vertical elements of the lateralforceresisting system andor distributes forces within the diaphragm. Siteblauvelt engineers cranberry township, pa pittsburgh, pa b s d i design.
The software are nice and easy on all win tablet pad. On the other hand, diaphragms also help to improve the loadsharing characteristics of bridges. This manual is intended to provide general guidance, and not solutions that are specific to any project. Therefore, diaphragms may not be necessary in case bridge bearings are placed directly under the webs because loads in bridge decks can be directly transferred to the bearings. Note, however, that this design does not eliminate the need for movable joints. Prestressed, precast girder information has been added. The diaphragm of a structure often does double duty as the floor system or roof system in a building, or the deck of a bridge, which simultaneously supports gravity loads. With integral bridges, the end diaphragm acts as a cross girder or trimmer. Figure 42 effect of partial end panel bracing on girder buckling stress. This was changed because of the obvious confusion it caused the design live load load case is the envelope of the individual design live loads.
Diaphragms and crossframes may be placed at the following locations along the bridge. External intermediate diaphragms or crossframes can help in some instances to obtain a. The diaphragm is the supporting portion of the bridge that goes between the girders and at the ends of the girders. New bridge design information is continually developing. The bridge models were analyzed for a lateralimpact load that was applied to the bottom flange of the exterior girders at the diaphragm location and away from the diaphragm location. It is not intended to replace the aashto lrfd bridge design specifications or any other design guide or regulatory code. Building structure behavior in response to earthquake or wind is heavily dependent upon the nature, extent and stiffness of floor and roof diaphragms.
Bridge and structures detailing policy manual page i revision summary. Each spreadsheet contains formulas, reference code sections, and graphic drawings. Lrfd steel girder superstructure design example lrfd. When diaphragms are defined for individual girder bays ie. Structural design software collection structural design. Seismic behavior of concrete end diaphragms in straight. Structure magazine steel deck diaphragm design 101. The end diaphragms are rigid so that no displacements are permitted in their.
Threespan continuous straight composite i girder load and resistance factor design third edition customary u. Due to tolerance issues, the program may not place diaphragms that are too close the bearing line or would intersect the. The entire guideline has been converted to reflect the aashto lrfd bridge design specifications lrfd. For continuous composite bridges, shear connectors are normally provided throughout the length of the bridge. Factors that determine the size of the hydraulic jack in addition to the weight of the structure includes the clearance difference between the pier cap or abutment and the bottom of girder or diaphragm. Note that the global yield strength in either the longitudinal or. Bridge diaphragm faq technical knowledge base computers. Wisconsin department of transportation bridge manual standard. Designing precast, prestressed concrete bridge girders for lateral stability. There are various issues that bridge abutments may exhibit during earthquakes for example inadequate seat length in the case of seat type abutment, large gap between end diaphragm of bridge superstructure and backwall, inadequate transverse andor longitudinal shear strength, and vulnerable end diaphragm in the case of monolithic abutment. Added a new input item to the project control menu. Bridge diaphragm technical knowledge base computers. However, when braces are normal to the girder lines, the two ends of the.
Modeling, analysis and design of bridge structures have been integrated into csibridge to create the ultimate in computerized engineering tools. The design of the eds2 bridge starts from the global yield strengths in the longitudinal and transverse direction, p l and p t, which are the same as for eds1 nonskew equivalent bridge. The ease with which all of these tasks can be accomplished makes csibridge the most versatile and productive software program available on the market today. A cofferdam is a structure that retains water and soil that allows the enclosed area to be pumped out and excavated dry. It looks like there are some good answers from a structural perspective. Analytical investigation of buckling restrained bracesa. Diaphragms are usually constructed of plywood or oriented strand board in timber construction. Bridge design guide the texas department of transportation ftp. Download structural bridge design free trial autodesk. Additional weld connection requirements are presented in s6.
Steel plate girder diaphragm and crossbracing loads fdot. The design live load load case is the envelope of the individual design live loads. After pouring the entire deck slab, except for the portions of the deck immediately adjacent to the integral abutment approximately the end 4 ft. Cofferdam, cofferdam design, cellular cofferdams deep. Bridge end details have been refined due to experience gained over the years. Comprehensive design example for prestressed concrete psc. Design of continuous highway bridges with precast, prestressed concrete girders nchrp report 322 design of precast prestressed bridge girders made continuous software programs rmcalc from washington dot. Structural design software collection structural design spreadsheets. Structural design software provides software created using microsoft windows excel 201020 or 2016 office 365. Singlefamily residential wood lightframe construction. Modeling and analysis of diaphragms ram staad opentower. Diaphragm is a member that resists lateral forces and transfers loads to support.
It is needed for lateral stability during erection and for resisting and transferring earthquake loads. For the bridge without diaphragms, the program consists of one. Bidirectionalresistant ductile end diaphragms with buckling. Slight curvature can be allowed, but must be considered on a casebycase basis. Using the steel deck institute sdi diaphragm design manual, third edition, we can determine the required deck fastening. Design of continuous highway bridges with precast, prestressed concrete girders nchrp report 322 design of precast prestressed bridge girders made continuous software. The program calculates the required length of the structure in soil, the internal forces on the structure and verifies crosssections rc, steel, vinyl, timber. This would change deflections somewhat, since the end diaphragm is going to change load distributions from your slab to your beams. Aashto lrfd bridge design specifications specific to new mexico bridge design practice so that uniformity in bridge design procedures will be attained. In eds1, the bottom connection of the pair of brbs oriented in the skew direction can be connected. The geo5 sheeting design program is used to perform a quick design of cantilevered diaphragm walls or a basic design of anchored diaphragm walls tieback.
Diaphragm design troubles and woes structural engineering. Divided the project information bradd input menu in to two submenus. Crossframe and diaphragm behavior for steel bridges with. Some of the diaphragms are posttensioned and some contain normal reinforcement. Since the steel girder has been designed as a composite section, shear connectors must be provided at the interface between the concrete deck slab and the steel section to resist the interface shear. Here, the eds at each end of the bridge has one long and one short brb. Diaphragm design troubles and woes bhiggins structural 31 mar 17 19. Bridge diaphragm technical knowledge base computers and. The project control menu was created to contain information related to all components of the bradd job.
The design of steel bridge girders is often controlled by lateraltorsional buckling. Crossframe diaphragm bracing of steel bridge girders rosa p. A new loads chapter has been added to aid in modeling an integral abutment bridge for analysis. Pdf seismic behavior of concrete end diaphragms in straight. Two end diaphragms are provided without any intermediate diaphragm. For certain bridges designed with bradd, the total factored reaction in the geometry output file, sole plate design output table was too large to print resulting in a series of asterisk characters displaying in the file. Added support for aashto lrfd bridge design specifications, 7th edition. Cofferdams are commonly used for construction of bridge piers and other support structures built within water. With concentrated moments of 1 kft applied to each end the. Designing precast, prestressed concrete bridge girders for. An owners perspective the washington state department of transportation wsdot investigates initial lifting, hauling, and erection conditions during the design of precast, prestressed concrete bridge girders. The end portion of the deck is poured simultaneously with the end diaphragm. Bridge automated design and drafting software cxi 26. This will be most relevant if your bridge has a small distance between diaphragms less than twice the distance between primary beams, according to classic slab methods such as rusch.
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