Bridging Your Innovations to Realities

Transcription

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2 Contents 1. Objective 2. General Overview - midas Civil Software 3. Introduction Balanced Cantilever Bridge 4. Live Modelling Balanced Cantilever Bridge 2

3 1. Objective Objective 1.0 To model and analysis of Balanced Cantilever Bridge in midas Civil. 2.0 To introduce the fast way of modelling through Wizard which consist of not only modelling but boundary condition, static loading, construction stages etc By the end of the series attendees will be conversant with FCM bridge wizard for modelling of Box Girder Bride. 3

4 1. Objective General Overview Modelling Loading Construction Stage Perform Analysis & Results Midas Civil Overview Balanced Cantilever Bridge Introduction Project Introduction Webinar Model Introduction Modelling Fixed Support Point Spring Support Elastic Links & Bearings Point, Beam Load Temperature Load Moving Load Prestressed Tendon Construction Schedule Structure, Boundary, Load Group Reaction, Deformation, Force, Stress Moving Load Tracer Tendon Loss Graph Day One Day Two Day Three 4

5 Contents 1. Objective 2. General Overview - midas Civil Software 3. Introduction Balanced Cantilever Bridge 4. Live Modelling Balanced Cantilever Bridge 5

6 1. General Overview Midas Civil is FEA software for analysis & design of Bridges Distributed worldwide & Leader in high profile projects A partial list of Users T Y Lin URS Corp. Michael Baker Jr. Parsons Corp. Hyder Burgess & Niple Figg Bridge Engineers Arup OTAK Akins Maunsell AECOM Group HNTB Corp. Halcrow Parsons & Brinckerhoff Roughan & O'Donovan McCormick Rankin Corp. WSP COWI Scott Wilson Strasky, Husty Delcan Ministry of Transportation of Ontario Royal Haskoning PennDOT California DOT Florida DOT Oregon DOT 6

7 1. General Overview Application Areas Cable stayed bridge & Extra-dosed bridge Staged segmental post-tensioned bridge Curved steel plate and composite girder bridge Conventional bridge (Skewed slab, Frame & Culvert) Suspension bridge Integral bridge Subway structure Tunnel structures Sewage treatment plant Heat of hydration for mass concrete Advanced Technology 7

8 Why midas Civil FEM FBM BEM 2-D 3-D General Purpose Special Purpose Structural Engineer Geotechnical Engineer Bridge Underground Structure Building Plant Tunnel Dam Analysis and Design Analysis only 8

9 1. General Overview Conventional Bridge Staged Segmental Bridge Cable-stayed Bridge & Suspension Bridge 9

10 1. General Overview Railway bridge Underground structure Soil-structure interaction Offshore structure Rail track-structure interaction Subway station Purification plant Nonlinear static Nonlinear time history analysis Wave load Response spectrum analysis Pushover analysis Seismic analysis Inelastic time history analysis Nonlinear time history analysis with damper or Isolator Multiple support excitation Linear local buckling analysis of steel member Detailed analysis Plastic analysis of connection (Mohr-Coulomb, von-mises) Heat of hydration analysis 10

11 Contents 1. Objective 2. General Overview - midas Civil Software 3. Introduction Balanced Cantilever Bridge 4. Live Modelling Balanced Cantilever Bridge 11

12 1. Introduction Balanced Cantilever Bridge 1. Balanced cantilever construction implies construction of cantilever segments from a pier in a balanced fashion on each side until the mid span is reached and a closure known as stitch/key segment is made with other half span cantilever constructed from the preceding pier. 2. The procedure is as follows: The form work is suspended from the end of the last segment. The new segment is cast and once the concrete has developed a predetermined strength, the section is post tensioned to the rest of the bridge. The same erection process is repeated till the structure is completed. 12

13 1. Introduction Balanced Cantilever Bridge PSC Segments Stitch Segment End Span 13

14 1. Introduction Balanced Cantilever Bridge 14

15 1. Introduction Balanced Cantilever Bridge FCM (Free cantilever Method) 1. It is generally used in a terrain where obstacles such as rivers, creeks and roads lie under the bridge, which present difficulties in installing conventional shoring. 2. FCM is generally used for long span bridges, which are typically accompanied with high piers. 3. Since it involves constructing balanced cantilevers from a pier, it is often referred to as a balanced cantilever bridge. 15

16 1. Introduction Balanced Cantilever Bridge 1. Less Space Required Construction in urban area where temporary shoring would disrupt traffic services below. 2. Less Formwork Required 3. Larger Spans Useful where span length is more but launching of girder is not possible. 1. More efficient, safe and economical Easy adoptability to curvature and super elevation. Useful for odd sizes, single span etc. 16

17 Construction over a working flyover 17

18 Construction over Railway lines 18

19 Suitable for Longer Spans 19

20 Considerations for a Bridge Engineer 1. Camber Due to cantilever action there will be some deformations, due to which, some construction defects may arise, specially when installing the stitch segment 2. Prestress Losses 3. Creep and Shrinkage Effect 4. Proper Construction Sequences 20

21 Contents 1. Objective 2. General Overview - midas Civil Software 3. Introduction Balanced Cantilever Bridge 4. Live Modelling Balanced Cantilever Bridge 21

22 4. Live Modelling Project Introduction Introduction 22

23 4. Live Modelling Project Introduction Introduction Euro and British code have been used for the model Material : CEB-FIP Moving Load User defined load have been defined 23

24 4. Live Modelling Model Introduction Specification of Structure Bridge Type: Balanced Cantilever Bridge Span Length: 48m + 77m m Width: m Moving Loads: IRC Time Dependent Material: IRC112:2011 Structural plan layout Internal Piers are monolithic and have a diameter of 5m. Bridge has a uniform radius of curvature of 182m. 24

25 4. Live Modelling Model Introduction Box Section Near mid span Near Int. Pier Loading Details 1. Self Weight of the Structure 2. Wet Concrete Load 3. Form work Load 4. Prestress Day 2 1. Moving Load 2. Response Spectrum 3. Temperature load 25

26 Prestress 4. Live Modelling Model Introduction Type of Tendon used : 1) 19T15 2) 17T15 72 No. of total tendon used 1395 N/mm 2 26

27 02 Load > Moving Load > Traffic Line Lanes Deciding Lane Placement First we need to decide where to place lanes over the deck. Crash Barrier of 1m each on both ends Carriageway Width : = 8.13 m According to IRC 6 Table 2: Live Load Combination For Carriage way Width 5.3< CW <9.6 We have 2 Combinations Lane of Class 70R running with minimum Eccentricity from the kerbs Lanes of Class A running with minimum Eccentricity from the kerbs. So, we need to define 3 lanes. 27

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