BRIDGE OF I-35 DESIGN USING PG SUPER - IAEME · 2018-06-30 · 2.3. PG Super Analysis and Design...

http://www.iaeme.com/IJCIET/index.asp 355 [email protected]

International Journal of Civil Engineering and Technology (IJCIET) Volume 9, Issue 6, June 2018, pp. 355–362, Article ID: IJCIET_09_06_041

Available online at http://www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VType=9&IType=6

ISSN Print: 0976-6308 and ISSN Online: 0976-6316

© IAEME Publication Scopus Indexed

BRIDGE OF I-35 DESIGN USING PG SUPER

Lokesh Kumar Anaimallur Mani

BIM Co-ordinator/Project Manager, Superior concrete products, Raider Drive,

Euless, Texas – 75062, United States

Arunraj E, Vincent Sam Jebadurai S, Daniel C, Joel Shelton J and Hemalatha G

Department of Civil Engineering,

Karunya Institute of Technology and Sciences, Coimbatore, India

ABSTRACT

The main objective of this study is to design all the simply supported pre-tensioned

prestressed concrete TxDOT I-girders for the seven-span Bridge 205 of I-35W

extension project in the most economical way. The minimum number of strands,

minimum number of girders, or minimum weight, or a combination of these items is to

be found and also to replace the steel plate girders at the second span by prestressed

TxDOT I-girders. The general arrangement plan, perform analysis in PGSuper and

design all 7 spans using AASHTO, LRFD and TxDOT specifications for presressed

concrete bridges are studied. The analysis was performed by using PGSuper

(Prestressed Girder Superstructure Design and Analysis), V. 2.9 (AASHTO LRFD

2014) for bridge design. Industry response to a recent survey1 suggests that

prestressed concrete bridge girders are the predominant element in establishing

overall quality guidelines for the advancement of precast concrete operations.

Keywords: Bridge, Girder Design, PG Super

Cite this Article: Lokesh Kumar Anaimallur Mani, Arunraj E, Vincent Sam Jebadurai

S, Daniel C, Joel Shelton J and Hemalatha G, Bridge of I-35 Design Using PG Super,

International Journal of Civil Engineering and Technology, 9(6), 2018, pp. 355–362.

http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=9&IType=6

1. INTRODUCTION

Industry response to a recent survey1 suggests that prestressed concrete bridge girders are the

predominant element in establishing overall quality guidelines for the advancement of precast

concrete operations. The quality control and specification control imposed by state and federal

departments of transportation establish the performance characteristics of these members and

often set the bounds for production strength. For years this upper bound was assumed to be

6000 psi (41 MPa). In the 1970s and early 1980s, considerable attention was given to the

advancement of cast-in-place, high strength concrete for the columns of multistory buildings.

2 During this time, production concrete strengths of 14,000 psi (97 MPa) were developed and

used. Until recently, there has been little corresponding development of high strength concrete

Bridge of I-35 Design Using PG Super


for the prestressed concrete industry. Research at Construction Technology Laboratories

(CTL) and Tulane University is examining the performance of decked bulb-tee beams using

10,000 psi (69 MPa) concrete.3 High strength concrete girder research is also being conducted

at the University of Minnesota and the University of Texas. These projects are examining the

strength and mechanical properties of high strength concrete for bridge bulb-tee girders. To

gain an insight into the probable performance of these girders, a historical assessment was

made of prestressed concrete girders and their mix designs. In this study, the optimized design

of this bridge to use only prestressed concrete girders and to be the most economical design

possibilities are studied. In doing this, we used 5-Tx54 girders in all spans except for Spans 2

and 4, which used 15 and 5 Tx70 girders, respectively.

2. PROJECT METHODOLOGY

2.1. Study of Plan and General Arrangement

Bridge 205 is a southbound bridge on North Tarrant Expressway Segment 3A North that is

900.35' long with 7 spans. It is on a horizontal curve with a radius of 5,800' and a vertical

curve with an entrance grade of +3% and an exit grade of – 2.46%. The second span utilizes

steel girders to cross the 230.56' between bents 2 and 3. Every other span on the bridge uses

Tx54 girders. Six of the seven bents are placed at a skew angle. The bridge has SSTR rails on

either side of the deck and an 8 ft CLF-RO fence on either side of spans 2 and 3. The overall

width of the bridge varies in span 1 and span 7 from 52'-8'' to 53'-5''. In spans 2-6, the overall

width of the bridge is a constant 53'-5''.

2.2. Design Parameters

The design was based on TxDOT 2013 Bridge Design manual. As per the project statement,

the design was based on an overall bridge length of 900.35', overall width of bridge of 53'.

and a roadway width of 51'. TxDOT T551 railing was used which has a weight of 382 plf. A

typical composite cast-in-place deck that is 8'' thick was used with a strength of f'c=4 ksi,

Ec=3605 ksi. The various type of TxDOT girder was used for each span as per need for the

most economical design.

The girders were designed with f'c = 8.5 ksi, f'ci= 6 ksi, Ec= 5255 ksi initially but it was

changed as per the requirement. The limitation of the practical length of a precast prestressed

concrete girder is 230'. The location of the piers was not allowed to change so we had to use

the same seven span as in the original design drawings. The width of the bridge was also not

allowed to be changed.

2.3. PG Super Analysis and Design Procedure

The PG Super software has a built in material library and modeling template. All 7 spans are

modeled according to the alignment given in the Bridge 205 plans. The overall plan and a

cross section view of span 1 is shown in figures 1 and 2. An initial trial is performed by

modeling the similar cross-sections and number of girders for all spans as given in input

drawings of Bridge 205. Multiple iterations of specification checks are performed with

numerous checks to optimize the design and meet project objectives. Girder size, number of

strands, amount of mild steel reinforcement and debonding patterns are tried in various

combinations to come up with our final design. The following are the checks PG Super does

when analyzing the bridge. Span 2 proved to be the most difficult span to design due to its

length of 230'. The original plans for Bridge 205 show this span using steel plate girders to

make transportation and construction feasible at site. Initial design started with 6-Tx70 girders

Lokesh Kumar Anaimallur Mani, Arunraj E, Vincent Sam Jebadurai S, Daniel C, Joel

Shelton J and Hemalatha G


and continued until the maximum number of girders could fit within the width of the bridge

while keeping in mind the minimum spacing requirement of 3.5’.

A similar approach is used to design the remaining spans and designs for every span are

grouped to streamline the designs and achieve feasibility in construction planning. 5-Tx54

girders were safe in every span except for Span 4. For Span 4 the maximum number of girders

for Tx54 with the minimum spacing was unsafe, hence increased the girder size to 8-Tx62.

An optional design with 5-Tx70 was checked for span 4 and was finalized since the material

weight was significantly lower than 8-Tx62 (Figure 5).

Figure 1 Overall Plan

Figure 2 Cross-Sectional View for Spans 1,3,5,6 and 7

Figure 3 Cross-Sectional View for Span 2

Figure 4 Cross-Sectional View for Span 4

Figure 5 Cross section and Debonding Pattern for Span 2 Girder A



Figure 6 Longitudinal View of Span 1- Girder

3. ANALYSIS AND RESULTS

The analysis was carried out in PG Super Software. Below are graphs depicting the shear and

moment diagrams as well as the displacement diagram for Span 1 Girder A.

Figure 7 Moment Results at Midspan‐Exterior Girder (Span 1)

Figure 8 Shear Results at Midspan‐Exterior Girder (Span 1)

Figure 9 Displacement Results at Midspan‐Exterior Girder (Span 1)




4. DESIGN SUMMARY

All girders used normal weight concrete and 270 ksi low-lax strands. A summary of design

specifications for all 7 spans is shown in Table 1. Table 2 shows a sample calculation of Mild

Steel Reinforcement for a Span 1 Girder A. Table 3 shows a comparison of Live Load

Distribution Factors calculated by PG Super for two sample interior beams with manual

calculations. Table 4 show the sample girder schedule for span 1 which is extracted from the

PG Super software. Sample Shear Reinforcement Detail is shown in table 6 and figure 7

shows the Camber and Deflection for Span 1 Girder A. Table 8 shows the Prestress Force and

Strand Stresses for Span 1- Girder A.

Table 1 Girder Design Summary (All Spans)

Span 1 Span 2 Span 3 Span 4 Span 5

Span 6

Span 7

Length of Span

102.5 ft 230.58 ft 111.17 ft 130 ft 98.09 ft 114 ft 114 ft

Girder Type

TX 54 TX 70 TX 54 TX 70 TX 54 TX 54

TX 54

Number of Girders

5 15 5 5 5 5 5

Spacing 12 ft 3.52 ft 12 ft 7 ft 12 ft 12 ft 12 ft

Number of Strands

48 70 48 56 48 54 54

Dia. of Strands

0.6” 0.7” 0.6” 0.7” 0.6” 0.6” 0.6”

Straight Strands

40 70 40 40 40 46 46

Harped Strands

8 54 8 8 8 8 8

Debonded Strands

0 22 0 12 0 0 0

Table 2 Mild Steel Reinforcement Design for Span 1- Girder A

Row# Measured

From

Distance from

End (ft)

Bar Length

(ft)

Girder Face

Cover (in)

Bar Size

# of Bars

Spacing (in)

1 Full Length Top 1.5 #4 4 10.7

2 Left End 0.125 3 Bottom 3.25 #5 2 26

3 Left End 0.125 3 Bottom 5.25 #5 2 26

4 Right End 0.125 3 Bottom 3.25 #5 2 26

5 Right End 0.125 3 Bottom 5.25 #5 2 26

Table 3 Distribution Factor for an Interior Beam

Distribution Factors Span/Girder Calculated PGSuper

Live Load Distribution Factor for Moment (Strength and Service Limit States)

1D 0.8542

0.8042* 0.845

Live Load Distribution Factor for Moment (Strength and Service Limit States)

5D 0.8612 0.908



Table 4 Sample Girder Schedule

Span 1 1 1 1 1

Girder A B C D E

Girder Type Tx54 Tx54 Tx54 Tx54 Tx54

Prestressing Strands

NO (Nh+Ns) 48 48 48 48 48

Size 0.600 in

Dia 0.600 in

Dia 0.600 in

Dia 0.600 in

Dia 0.600 in

Dia

Strength Grade 270

Low Relaxation

Grade 270 Low

Relaxation

Grade 270 Low

Relaxation

Grade 270 Low

Relaxation

Grade 270 Low

Relaxation

Eccentricity at CL

18.508 in 18.508 in 18.508 in 18.508 in 18.508 in

Eccentricity at End

12.508 in 12.508 in 12.508 in 12.508 in 12.508 in

Prestressing Strands

Depressed Depressed Depressed Depressed Depressed

No. (# of Harped Strands)

8 8 8 8 8

Yb of Top Most Depressed

Strands at End 44.500 in 44.500 in 44.500 in 44.500 in 44.500 in

Concrete

Release strength fci

6.500 KSI 6.500 KSI 6.500 KSI 6.500 KSI 6.500 KSI

Minimum 28-day

Compressive strength fc

7.300 KSI 7.300 KSI 7.300 KSI 7.300 KSI 7.300 KSI

Table 5 Optimal Design

Span 1 1 1 1 1

Girder A B C D E

Girder Type Tx54 Tx54 Tx54 Tx54 Tx54

Design load compressive stress

(Top CL) 3.483 KSI 3.832 KSI 3.832 KSI 3.833 KSI 3.463 KSI

Design load tensile stress (Bottom CL)

-3.595 KSI

-4.025 KSI

-4.025 KSI

-4.026 KSI

-3.560 KSI

Required minimum ultimate moment

capacity

7551.83 kip-ft

8285.01 kip-ft

8285.01 kip-ft

8285.01 kip-ft

7488.70 kip-ft

Live load distribution factor for moment

0.84503 0.84503 0.84503 0.84503 0.84503

Live load distribution factor for shear

1.19982 1.19982 1.08232 1.19982 1.19982

Design load compressive stress

(Top CL) 3.483 KSI 3.832 KSI 3.832 KSI 3.833 KSI 3.463 KSI

Design load tensile stress (Bottom CL)

-3.595 KSI

-4.025 KSI

-4.025 KSI

-4.026 KSI

-3.560 KSI

Required minimum ultimate moment

capacity

7551.83 kip-ft

8285.01 kip-ft

8285.01 kip-ft

8285.01 kip-ft

7488.70 kip-ft

Live load distribution factor for moment

0.84503 0.84503 0.84503 0.84503 0.84503




Table 6 Sample shear reinforcement detail

Zone Zone

Length ft

Bar Size, #

Spacing No of

Vertical Legs

No of Legs extended Into

Deck

Confinement Bar Size

1 3.208 4 3 2 2 None

2 10 4 6 2 2 None

3 10 4 8 2 2 None

4 15 4 12 2 2 None

5 to mid span

4 18 2 2 None

Table 7 Camber and Deflections

Camber and Deflection for Span 1 Girder A

Design Camber 4.004 in 0.334 ft

Deflection (Prestresssing) 4.206 in 0.350 ft

Deflection (Girder) -1.427 in -0.119 ft

Deflection (slab and diaphragms) -1.373 in -0.114 ft

Deflection (Traffic Barrier) -0.097 in -0.008 ft

Deflection (Overlay) 0.000 in 0.000 ft

Deflection (User Defined DC) 0.000 in 0.000 ft

Deflection (User Defined DW) 0.000 in 0.000 ft

Screed Camber, C 1.470 in 0.122 ft

Excess Camber (Based on Design Camber) 2.535 in 0.211 ft

Live Load Deflection (HL93 0 – Per Lane) -1.330 in -0.111 ft

Table 8 Prestress Force and Strand Stresses for Span 1- Girder A

Effective Prestress at Midspan

Loss Stage Permanent Strand

Force (Kip) Effective Loss (KSI) Fpe (KSI)

At Jacking 2109.24 0.000 202.500

Before Prestress Transfer 2109.24 0.000 202.500

After Prestress Transfer 1867.44 23.214 179.286

At Lifting 1867.44 23.214 179.286

At shipping 1687.81 40.460 162.040

After Deck Placement 1508.19 57.706 144.794

After Superimposed Dead Loads

1508.18 57.706 144.794

Final 1508.18 57.706 144.794

Final with Live Load 1508.18 57.706 144.794

5. CONCLUSION

The optimized design of this bridge to use only prestressed concrete girders and to be the

most economical design possibilities are studied. In doing this, we used 5-Tx54 girders in all

spans except for Spans 2 and 4, which used 15 and 5 Tx70 girders, respectively. This design

allowed our bridge to be as lightweight as possible, while remaining safe for traffic.



REFERENCE

[1] Dolan, C. W., and LaFraugh, R. W., "High Strength Concrete in the Precast Concrete

Industry," PCI JOURNAL, V. 38, No. 3, May-June 1993, pp. 16-19.

[2] Russell, H. G. (Editor), High-Strength Concrete, Special Publication SP-87, American

Concrete Institute, Detroit, Ml, 1985,290 pp.

[3] Bruce, R. N., Martin, B. T., Russell, H. G., and Roller, J. J., "Feasibility of Utilizing High-

Strength Concrete in Design and Construction of Highway Bridge Structures," Louisiana

Department of Transportation and Development, Interim Report, Tulane University, New

Orleans, LA, December 1992.

[4] AASHTO, Standard Specifications for Highway Bridges, Fifteenth Edition, American

Association of State Highway and Transportation Officials, Washington, D.C., 1992.

[5] Ontario Highway Bridge Design Code, Ontario Ministry of Transportation and

Communication, Toronto, Ontario, Canada, 1979.

[6] Neville, A. M., Properties of Concrete, Third Edition, Pitman Publishing, Marshfield,

MA, 1981.

[7] ACI Committee 318, "Building Code Requirements for Reinforced Concrete (ACI 318-

89)," American Concrete Institute, Detroit, Ml, 1989.

[8] Pfeiffer, D. W., Marusin, S., and Landgren, J. R., "Energy Efficient Accelerated Curing of

Concrete," Technical Report No. 1, Precast/Prestressed Concrete Institute, Chicago, IL,

1981.

[9] "Strength Design Age of Concrete for Prestressed Highway Girders," Report Number

FHW A/RD-86-036, Federal Highway Administration, Washington, D.C., 1986.

[10] "25 Year Old Prestressed Concrete Bridge Girders Tested," PCI JOURNAL, V. 29, No. 1,

January-February 1984, pp. 177-179.

[11] Riessauw, F. G., and Taerwe, L., "Tests on Two 30 Year Old Prestressed Concrete

Beams," PCI JOURNAL, V. 25, No. 6, November-December 1980, pp. 70-73.

[12] Dolan, C. W., and Hu, C., "Prestressed Concrete Bridge Durability in Delaware,"

Concrete International, V. 13, No.9, September 1991, p. 47.

BRIDGE OF I-35 DESIGN USING PG SUPER - IAEME · 2018-06-30 · 2.3. PG Super Analysis and Design...

Documents

Transcript of BRIDGE OF I-35 DESIGN USING PG SUPER - IAEME · 2018-06-30 · 2.3. PG Super Analysis and Design...