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CIVL 3121 Influence Lines - Part 1/5 Live Loads for Bridges Live Loads for Bridges  In our previous discussions we mentioned that the primary live loads on bridge spans are due to traffic  The heaviest loads are those produced by large transport trucks  The American Association of State and Highway Transportation Officials (AASHTO) has a series of specifications for truck loadings  For two-axial trucks AASHTO designates these vehicles as H series trucks  For example, a H15-44 is a 15-ton truck as reported in the 1944 specifications  Trucks that pull trailers are designated as HS, for example HS 20-44 (a 20-ton semi-trailer truck)  In general, a truck loading depends on the type of bridge, its location, and the type of traffic anticipated Live Loads for Bridges Live Loads for Bridges  The size of the “standard truck” and the distribution of its weight is reported in the AASHTO code  The “H” loading consists of two-axial truck  The number following the H designation is the gross weight in tons of the standard truck  The “HS” loading consists of tractor truck with semi-trailer  The number following the HS designation is the gross weight in tons of the standard truck 14 feet H 20-44 kips H 15-44 kips 32 kips 24 kips 0.1 W 0.4 W 0.1 W 0.4 W HS20-44 kips HS15-44 kips 32 kips 24 kips 32 kips 32 kips W = Total weight of truck and load Live Loads for Bridges The AASHTO standard H20 and HS20 trucks Live Loads for Bridges The AASHTO specifications also allow you to represent the truck as a single concentrated load and an uniform load For H20-44 and HS20-44:  Concentrated load 18 kips for moment 26 kips for shear  Uniform loading 640 lb/ft of load lane CIVL 3121 Influence Lines - Part Live Loads for Bridges 2/5 Live Loads for Bridges The AASHTO specifications also allow you to represent the truck as a single concentrated load and an uniform load  You can probably see that once the loading has been selected, you have to determine the critical position of the truck on the structure (bridge) For H15-44 and HS15-44:  This is an excellent application for influence lines  Concentrated load 13.5 kips for moment 19.5 kips for shear  Uniform loading 480 lb/ft of load lane Live Loads for Bridges  In many cases, vehicles may bounce or sway as they move over a bridge  This motion produces an impact load on the bridge  AASHTO has develop an impact factor to increase the live load to account for the bounce and sway of vehicles I Live Loads for Bridges Impact loading is intended to transfer loads from the superstructure to the substructure  Superstructures including legs of rigid frames  Piers excluding footings and those portions below ground line  Portions above ground line of concrete and steel piles that support the super structure 50  0.3 L  125 where L is the length of the span in feet Live Loads for Bridges Impact shall not be included in loads transferred to footings or to those parts of piles or columns that are below ground Live Loads for Bridges Example: Consider our standard AASHTO HS20-44 truck traveling over the span of some structure 8k  Abutments, retaining walls, piles excepts as specified before  Foundation pressures and footings  Timber structures  Sidewalk loads  Culverts and structures having feet or more of cover A x 32 k 14 ft 32 k 30 ft B CIVL 3121 Influence Lines - Part Live Loads for Bridges 3/5 Live Loads for Bridges  Shear - To examine how a series of concentrated loads effect the shear lets consider our “standard truck” and its effect on the shear at point C on the beam shown above  First we need the influence line for the shear at point C Using the Muller-Breslau principle construct the influence line for the shear at point C V 50 ft 50 ft A V B VC 50 ft A 50 ft C The change in shear is equal to B 0.5 x -0.5 Live Loads for Bridges Live Loads for Bridges  Let’s try to find the maximum positive shear at point C  There are three cases to examine, one for each of the three wheel forces as they pass over the point C 8k Case #1 32 k 14 ft A VC 32 k B 0.36 x VC 32 k 30 ft B 0.5 50 ft -0.06 -0.2 50 ft -0.5 VC Case  8k ( 0.06)  32k ( 0.2)  32k (0.5) 50 ft -0.36 x -0.5  19.52k Live Loads for Bridges  Let’s try to find the maximum positive shear at point C  There are three cases to examine, one for each of the three wheel forces as they pass over the point C 14 ft B 0.5 VC Case  8k (0.36)  32k (0.5)  32k (0.2)  17.44k Live Loads for Bridges A 30 ft 50 ft -0.5 32 k 32 k 0.2 0.06 50 ft VC Case  8k (0.5)  32k (0.36)  32k (0.06) 32 k 14 ft A VC 0.5 8k 8k Case #2 30 ft 50 ft Case #3  Let’s try to find the maximum positive shear at point C  There are three cases to examine, one for each of the three wheel forces as they pass over the point C x  9.12k  The maximum positive shear at point C is 19.52k  Let’s rework the previous problem to find the maximum negative shear at point C  There are three cases to examine, one for each of the three wheel forces as they pass over the point C  In this case, use the largest negative value from the influence line CIVL 3121 Influence Lines - Part Live Loads for Bridges Live Loads for Bridges  Let’s try to find the maximum negative shear at point C  There are three cases to examine, one for each of the three wheel forces as they pass over the point C 8k Case #1 32 k 14 ft A VC 32 k  Let’s try to find the maximum negative shear at point C  There are three cases to examine, one for each of the three wheel forces as they pass over the point C 8k Case #2 30 ft 0.5 0.36 50 ft x VC Case  8k (0.36)  32k ( 0.5)  32k (0.2)  9.44k VC  The maximum negative shear at C is -22.88k  In this case, the largest shear at C is the largest negative value, or Vmax = -22.88k 32 k 30 ft B 8k 32 k 32 k 0.5 50 ft -0.06 -0.2 -0.5 2k Live Loads for Bridges Example: Determine the maximum shear created at point C in the beam below due to the wheel loads of a moving truck The truck travels from right to left kN kN 5k C 12 ft 100 ft C B  22.88k Example: Determine the maximum moment created at point B in the beam below due to the wheel loads of a moving truck The truck travels from right to left B 30 ft x Live Loads for Bridges 100 ft 14 ft A 50 ft VC Case  8k (0.06)  32k (0.2)  32k ( 0.5) A  12.48k Live Loads for Bridges  Let’s try to find the maximum negative shear at point C  There are three cases to examine, one for each of the three wheel forces as they pass over the point C 14 ft x -0.5 -0.36 Live Loads for Bridges A B 0.2 50 ft 32 k 30 ft 50 ft -0.5 8k 32 k 0.5 0.06 VC Case  8k (0.5)  32k (0.36)  32k (0.06) 32 k 14 ft A B VC 50 ft Case #3 4/5 A 2m 1m 6m B kN 3m CIVL 3121 Influence Lines - Part End of Influence Lines - Part Any questions? 5/5 VSL Australia Post-Tensioning Systems OCT 2019 INTRODUCTION VSL CAPABILITIES MULTISTRAND POST-TENSIONING STRAND PROPERTIES – TO AS 4672 10 TENDON PROPERTIES 10 SELECTED DESIGN CONSIDERATIONS 11 VSL STRESSING ANCHORAGE TYPE SC LIVE END 12 VSL COUPLING ANCHORAGE TYPE KAS - FOR USE WITH SC ANCHORAGE 13 INTERMEDIATE ANCHORAGE TYPE Z 14 VSL DEAD END ANCHORAGE 15 SHEATHING & CORROSION PROTECTION 16 DIMENSIONS OF PT-PLUS® DUCTS 16 ECCENTRICITY OF TENDONS 16 STRESSING SEQUENCE 17 STRESSING 17 GROUTING 17 JACK CLEARANCE REQUIREMENTS 18 STRESSING JACK DETAILS 18 SLAB POST-TENSIONING 21 STRAND PROPERTIES – TO AS 4672 22 TENDON PROPERTIES 22 SELECTED DESIGN CONSIDERATIONS 23 VSL STRESSING ANCHORAGE TYPE S5 – S6 LIVE END 24 VSL DEAD END ANCHORAGES TYPE H – TYPE P 25 VSL SLAB COUPLING ANCHORAGE TYPE S 26 JACK CLEARANCE REQUIREMENTS 27 STRESSING JACK DETAILS 27 INTERNAL STRESSING POCKET 27 ANCHORAGE REINFORCEMENT – S5-3, S5-4, S5-5, S6-3, S6-4 ANCHORS 28 ANCHORAGE REINFORCEMENT – S6-5 ANCHORS 28 ANCHORAGE REINFORCEMENT - TIES 29 STRESSING JACK DETAILS 29 GROUND ANCHORS 32 VSL PERMANENT ANCHOR FULLY ENCAPSULATED 33 VSL TEMPORARY ANCHOR 33 VSL PERMANENT GROUND ANCHORS - 15.2mm STRAND 34 VSL CT STRESSBAR GROUND ANCHORS 34 VSL TEMPORARY GROUND ANCHORS 34 VSL PERMANENT GROUND ANCHORS BEARING PLATE AND ANCHORHEAD 35 STRESSING 36 FLAT JACKS 39 CONTACT US 40 Post-tensioning is, even so being a mature technology, still a fantastic tool for the design engineer to actively define the internal load path in concrete structures by superposing a favorable internal stress state This permits to minimize deformations, helps to increase slenderness of members, reduces reinforcement congestion, enables segmental construction without need for wet joints and allows the use of high strength steel This brochure gives an overview of the available post-tensioning systems and their fields of application It provides guidance to practising engineers in the design of post-tensioned structures using VSL post-tensioning systems VSL is a recognised leader in the field of special construction systems Well proven technical systems and sound in-house engineering are the basis of the group’s acknowledged reputation for innovative conceptual structural solutions VSL has developed, manufactured and installed durable, state-of-the-art post-tensioning systems for over 60 years The VSL post-tensioning systems comply with international standards and approval guidelines for use on both new and existing structures VSL does not only select and offer the best suited post-tensioning hardware and layout for a given project but proposes also innovative detailing of the permanent work and construction techniques with the aim to improve durability, increase site safety and reduce construction time and costs VSL likes to work in partnership with owners and clients right from the conceptual stage VSL’s engineers can work closely with the design engineer during the design development stage and with the contractor's estimating team during the tender stage What differentiates VSL from other players in the market, is its holistic approach, which is fundamental in arriving at well balanced technical solutions respecting equally permanent work and construction aspects VSL’s biggest asset however is the quality of its highly experienced, multicultural staff /// 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 66/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 67/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 68/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 69/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 70/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 71/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 72/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 73/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 74/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 75/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 76/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 77/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 78/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 79/80 14/3/2020 https://www.slideshare.net/slideshow/embed_code/key/igSQwD5Zb2TFD3 pci girder 80/80