Project 1

Aim:-

1) Mention the need for a metro rail in a developing economy.

Answer:-

• 'Metro Rail' is a commuter-friendly transport providing the traveling public with c a fast, safer, reliable, comfortable, pollution-free, affordable, convenient, and eco-friendly service. The high-capacity Metro Rail System would reduce the ever-increasing traffic congestion on the city roads.
• The most efficient transportation system is space occupancy, energy consumption, and numbers transported.
• They are very high-capacity carriers, transporting many people during peak hours.
• Unlike buses and other modes of public transportation, metro rails are eco-friendly, cause much less sound pollution, and have no air pollution.
• They possess greater traffic capacity. It carries as much traffic as seven lanes of bus traffic and 24 lanes of car traffic.
• It reduces the journey time from 50% to 75%.
• The usage of metros should be promoted more and more as it helps in reducing the levels of greenhouse gases.
• The number of road accidents has also gone down drastically as people have chosen the Metro. Speeding usually happens when people are late for their work.
• Metro provides air-conditioned traveling with the best comfort at relatively cheap rates

2) Perform longitudinal analysis of 3 x 25m prestressed I-girder for metro viaduct in STAAD by creating the nodes, beams, and supports being assigned to those nodes for a slab and girder that has been presented in the videos.

Procedure:-

Step (1) - Creating Grid Modeling in STAAD.Pro

Creating node (0,0,0) -> Selecting Node using node cursor -> Copy it in X direction using Translation repeat option

Connect both the node -> Geometry -> Add beam

• According to the suitable size create a Girl model

Step (2):- Assigning Support

Specification -> Support -> Create -> Fix but -> Release ( MX, MY, MZ ) -> Add -> Select support 2 -> Select node -> Assign to selected nodes -> Assign

Specification -> Support -> Create -> Fix but -> Release ( FX, MX, MY, MZ ) -> Add -> Select support 3 -> Select node -> Assign to selected nodes -> Assign

Specification -> Support -> Create -> Fix but -> Release ( FZ, MX, MY, MZ ) -> Add -> Select support 4 -> Select node -> Assign to selected nodes -> Assign

Specification -> Support -> Create -> Fix but -> Release ( FX, FZ, MX, MY, MZ ) -> Add -> Select support 5 -> Select node -> Assign to selected nodes -> Assign

• Select a node according to suitable support and assign to it

Step (3):- Assign Property to Model

Specification -> Property -> Define -> General -> Insert the value Cross-section dimension of beam -> Add -> Select the property -> Select the beam -> Assign to selected beam -> Assign

• Repeat the same step according to the suitable dimension of different types of beam

Step (4):- Applying Loading on Model

I. Vehicle Definition

Loading -> Load & Definition -> Definitions -> Vehicle Definition -> Add

II. Dead Load.

Loading -> Load & Defination -> Load Case Detail -> Tital ( Dead Load ) -> Add -> Select Dead Load -> Add -> Self Weight Factor -1 -> Add -> Select Selfweight - 1 -> Assign to view -> Assign.

III. SIDL

Loading -> Load & Definition -> Load Case Detail -> Title ( SIDL ) -> Add -> Select SIDL -> Add -> Member Load -> Uniform Force -> W1 -8.34 Direction GY-> Add -> Select Load -> Select Suitable beam Beam -> Assign to selected beam -> Assign

• Repeat the same procedure for different beams according to suitable force.

IV. Load Generation

Loading -> Load & Definition -> Load Case Detail -> Add -> Load Genaration -> No of load to be generated -> Add -> Generted Load -> Position of coordinate -> Add

Step (5):- Analysis And Result

Analysis And Design -> Analysis Commands -> Run Analysis -> Go to post prossing mode -> Done

3) Prepare a transverse STAAD model of a U-girder with the following specifications:

Given Data:-

• Finite element model of U-girder with a span length of 30m.
• Having supports at 0.7m from both ends.
• Having the following geometrical properties:
  • Thickness of bottom slab – 300mm
  • Thickness of top web (both sides) – 240mm
  • Thickness of slant web - varying from 300mm to 240mm
  • Concrete grade M55.
  • Reference inputs can be taken from the relevant video sessions if needed.

Procedure:-

Step (1) - Creating Grid Modeling in STAAD.Pro

• Arranging the node in the shape of U Grider

• Connecting node by using add beam option

• Copy the node in X direction using the translation repeat option and assign the plate using add plate option

• Making Full U Girder model using translation repeat option.

Step (2):- Assigning Support

Specification -> Pinned suport -> Add -> select support 2 then select node -> Assign

Step (3):- Assign Property to Model

For Plate

Specification -> Property -> Thickness -> (Insert Plate thickness size) -> Add -> Select Plate -> assign

• Repeat the same procedure for different plates & also assess thickness in variable conditions.

For Beam

Specification -> Property -> Define -> Rectangular -> Size 0.01 x 0.01 material as DUMMY -> Select beam -> Assign to selected beam -> Assign

Step (4):- Applying Loading on Model

I. Dead Load.

Loading -> Load & Defination -> Load Case Detail -> Tital ( Dead Load ) -> Add -> Select Dead Load -> Add -> Self Weight Factor -1 -> Add -> Select Selfweight - 1 -> Assign to view -> Assign.

II. SIDL

Loading -> Load & Definition -> Load Case Detail -> Title ( SIDL ) -> Add -> Select SIDL -> Add -> Plate Load -> Partial Plate Pressure -> W1=-10 , X1= -0.8 , X2=0.8 , Y1=-0.5 , Y2=0.5 , Direction GY-> Add -> Select Load -> Select all bottom plate -> Assign to selected plate -> Assign

III. Live Load

Loading -> Load & Definition -> Load Case Detail -> Title ( Live Load ) -> Add -> Select Live -> Add -> Plate Load -> Concentrated Load -> W1=-78 , X= 0.2 , Y=0.245 , Direction GY-> Add -> Select Load -> Select Suitable plate -> Assign to selected plate -> Assign

• For Other Plate repeat the same procedure and change the value of X, Y

IV. Combination Of SLS & ULS

Loading -> Load & Definition -> Load Case Detail -> Add -> Define Combination -> Select load and inser the factor according to given in IRS CBC -> Add -> Close

Step (5):- Analysis And Result

Analysis And Design -> Analysis Commands -> Run Analysis -> Go to post prossing mode -> Done

• Maximum MY in SLS combination

Plate no 197 has a maximum bending moment

• Maximum MY in ULS combination

4) For a prestressed U girder, calculate the following with the given data

Given Data:-

• Area = 2.1735m2
• I = 0.74035m4
  • Calculate Prestressing force considering 76.5% jacking stress with 72 no. of strands.
  • Calculate the Section Modulus of U-girder considering y_bot = 0.594m
  • Calculate eccentricity of Prestress tendons from CG of section considering y_bot = 0.594m and cg of PT cables = 0.140m from soffit level.
  • Calculate Stress at bottom of U-girder considering M=10628.58kN-m and details mentioned previously.

Assumption data of characteristics of prestressing steel:-

• Nominal area of strand: As = 140 mm2.
• Nominal ultimate stress : fpu = 1860 Mpa
• Maximum jacking stress : 0.765 fpu = 1422.9 Mpa
• Modulus of elasticity: Ep = 195000 Mpa.

Que (1). Calculate Prestressing force

Answer:-

• No of Strand used (n) = 72
• Prestressing force applied (P)

= (0.765 fpu X As X n X (1- Loss)) / 1000 kN

= (1422.9 X 140 X 72 X 76.5 ) / 1000 kN

= 10972.2 kN

Que (2). Calculating section Modulus ( Z ) = I/Y

Answer:-

• For Checking stress st bottom, y_bot = 0.594m

Z = `(0.74035)/0.594`

= 1.2464 m3

Que (3). Calculate eccentricity of Prestress tendons from CG of section

Answer:-

• CG of the section to Cg of tendons (e)

= 0.594 - 0.140 M

= 0.454 M

Que (4) Calculate Stress at bottom of the U-girder

Answer:-

• Stress @ Bottom

= `P/A +(P xx e)/Z - M/Z`

= `10972.2/2.1735 + (10972.2 xx 0.454 )/1.2464 - 10628.58/1.2464`

= 0.517 N/mm2