공학박사학위 논문 지점의 상승하강 공법을 이용한 개구제형 강합성 거더교의 설계와 거동 Behavior and Design of Open Steel Box Girder Bridges by Up-down Construction Method 2009 년 8 월 인하대학교 대학원 토목공학과 도다이탕 (Do Dai Thang) 공학박사학위 논문 지점의 상승하강 공법을 이용한 개구제형 강합성 거더교의 설계와 거동 Behavior and Design of Open Steel Box Girder Bridges by Up-down Construction Method 2009 년 8 월 지도교수 : 구 민세 이 논문을 박사학위 논문으로 제출함 인하대학교 대학원 토목공학과 도다이탕 (Do Dai Thang) FF@FsPet'-" BsR600Z G&lb Eo++ b&{vinbA &["te= €*t [o Behavior and Design of Open Steel Box Girder Bridges by Up-down Construction Method By Do Dai Thang A DISSERTATION Submitted to the faculty of INHA UNIVERSITY In partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPY Department of Civil Engineering August, 2009 ABSTRACT This research investigates the behavior of open steel box girder bridge by up-down construction method. The steel box girder with open-trapezoidal cross section, partial-length prefabricated concrete slab and double composite section by cast-in-place concrete on bottom flange is considered. The three-dimensional finite element models, considering construction sequence in modeling, have been used to carry out the analysis. A parametric study is used to investigate the effects of some structural characteristics on the behavior of steel box girder.
These parameters include the variation of lifting upward and lowering downward height, the length and depth of bottom concrete slab, the length of partial prefabricated concrete slab and the steel strength. A modification of the time-dependent behavior for double composite section with difference in ages and modulus of elasticity of top and bottom concrete slab are presented. An overview of the effect of lifting upward and lowering downward to the stability design such as web buckling and top lateral bracing are given. Optimization of the plate thickness of cross section by considering construction sequences is also presented as additional consideration.
Finally the recommendations are made for the engineers to the design and construct steel box girder bridges by up-down construction method. -i- TABLE OF CONTENTS Title Page No. i Table of Contents. ii List of Figures.
v List of Tables. xi CHAPTER 1 INTRODUCTION 1.2 Objectives and Scope. 4 CHAPTER 2 LITERATURE REVIEW 2.1 Fundamental of Up-Down Construction Method .2 Up-Down Construction Method Applied for Steel Box Girder .4 Partial Length Prefabricated Deck Concrete Slab .5 Proposed Up-Down Method for Open Steel Box Girder. 26 CHAPTER 3 ANALYTICAL STUDIES 3.1 Finite Element Model Description .2 Nonlinear Finite Element Analysis Modeling .4 Comparisons the Results.
50 CHAPTER 4 PARAMETRIC STUDIES 4.2 The Effect of Lifting-up and Lowering-down Height .3 The Effect of Bottom Concrete Slab.4 The Effect of Length of Partial Pre-fabricated Deck Concrete Slab .5 The Effect of Steel Strength .5 The Effect of the Top Flange .6 The Effect of Sequence Construction on Three, Four-Span Bridge. 71 CHAPTER 5 TIME DEPENDENT ANALYSIS OF DOUBLE COMPOSITE SECTION 5.1 Prediction Models of Creep and Shrinkage .2 Modified Gilbert’ Method, an Accurate Time-Dependent Analysis with Consideration of Interval Time during Up-Down Method.3 Calculation of Short-term and Long-term Composite Section according to AASHTO LRFD Specification.4 Comparisons of the Result. 96 - iii - CHAPTER 6 ADDITIONAL DESIGN CONSIDERATION 6.2 Suggested Construction Details .3 Optimum Cost of Steel Box-Girder by Varying Plate Thickness.4 Example Design and Evaluation. 135 CHAPTER 7 SUMMARY AND CONCLUSIONS 7.3 Recommendations for Further Research.
148 APPENDIX A TIME DEPENDENT DESIGN OF COMPOSTIE STEEL BOX GIRDER BRIDGE A.1 Properties of Cross Section .2 Determination of Bending Moment during Construction Sequence.3 Time Dependent Analysis by Modification of Gilbert's Method.4 Time Dependent Analysis by AASHTO LRFD Provision. 173 APPENDIX B DESIGN EXAMPLE B.1 Calculation Bending Stress for Model 1 .2 Calculation Bending Stress for Model 2. 188 - iv - LIST OF FIGURES Figure Page No.2 Two continuous spans .3 Steel box girder in two continuous spans .4 Detail install bottom slab in steel box girder applied up-down construction method .5 Double composite bridge Neuötting, (Hanswille, 2001) .6 Partial-length prefabricated steel box girder component .7 Construction sequence in two-spans continuous bridge.8 The normal stress at negative moment region .9 The normal stress at positive moment region .1 Example of Model 1 of two-span continuous bridge in ANSYS .2 Model 1: a) Girder Side view b) Cross section .3 Model 2: a) Girder Side view b) Cross section .4 Idealized stress-strain relationships for steel (Bureau et.5 Uniaxial compressive and tensile stress-strain curve for concrete a) Real curve relationships (Bangash 1989) b) Idealized curve relationships (Hognestad, 1951) .36 -v- Figure Page No.6 Residual stress distribution for 800mm flange .7 Residual stress distribution for 1,800mm height web .8 Idealized residual stress distribution in top and bottom flange and web plates due to flame cutting and welding (AWS 2001) .10 Longitudinal stress of top flange at stage 3 (half bridge) .11 Longitudinal stress of top concrete slab at stage 5 (half bridge) .12 Longitudinal stress of bottom concrete slab at stage 3 .13 Equivalent stress at midpoint of top flange .14 Equivalent stress at midpoint of bottom flange .15 Longitudinal stress of top flange at midpoint .16 Longitudinal stress of bottom flange at midpoint .17 Longitudinal stress of top concrete slab at midpoint .18 Longitudinal stress of top concrete slab at midpoint .19 Transverse stress of top slab across the width .20 Transverse stress of bottom slab across width at the support.50 - vi - Figure Page No.1 Stress of top slab (in the case L=50m) .2 Initial compression stress of top slab.3 Upward lifting height for different span length.4 Relationship of the stress of top slab at service stage with lift- up height in unequal two span bridge of 65-90m length .5 Compression stress of bottom slab in stage 4.6 Tensile stress of top flange in stage 3.7 Compression stress of bottom flange in stage 3 .8 Bending moment diaphragm and location of cast-in-place the top and bottom slab concrete .9 An example of slope for surface of bottom concrete slab .10 Parameter study result of prefabricated slab length.11 Layout of hybrid girder a) Grade 36/50 b) Grade 50/70 .12 Variation of stress of top flange with respect the changing of thickness or width of top flange at stage 3 (in case of L=50m).13 Typical changing of thickness and width of top flange near the support region.14 Bending moment in case 1 of three-span continuous bridge.15 Bending moment in case 2 of three-span continuous bridge.68 - vii - Figure Page No.16 Bending moment in case 3 of three-span continuous bridge.17 Bending moment in case 1 of four-span continuous bridge .18 Bending moment in case 2 of four-span continuous bridge .19 Bending moment in case 3 of four-span continuous bridge .1 Prediction of creep coefficient using different models .2 Prediction of shrinkage strain using different models .3 Notification of cross section a) Elevation; b) Composite section 0; c) Composite section 1; d) Composite section 2; d) Short-term strain .4 Effect of different creep and shrinkage prediction models on double composite section.1 Bending moment and shear force diaphragm due to lifting-up the interior support.2 Finite element model M4.3 Tension field action in web at end panel of exterior supports.4 Tension field action in web at panel adjacent to interior support .5 Tripping of top flange.103 6,6 Lateral torsional buckling .7 Cross section of a three-pan continuous bridge. 106 - viii - Figure Page No.8 Steel box girder with longitudinal web stiffener .9 Arrangement of longitudinal stiffener in web plate .10 Transverse stiffener spacing in web plate at interior support .11 Top-lateral single-diagonal truss system .12 Torsional moment cause by shear force Rup of one-tenth step .13 Top lateral bracing of Model 1 .14 Ratio of top flange stress due to lift-up and girder self-weight 113 6.15 Construction details for Double composite section .16 Detail at support for the case of two load-bearing each side .17 Detail at support for the case of one load-bearing each side .18 Detail at support for case of one load-bearing each side .19 Stress in plate diaphragm at bearing.20 Structural geometry of steel box girder .21 A half of four-span continuous beam divided into 16 segments (case L=50m, seg=8) .22 Variations of equivalent weight for the case kf/km=0 .23 Variations of equivalent weight for different kf/km .24 Variations of Δf1 for different segment to L (w=200kN/m) .127 - ix - Figure Page No.25 Variations of (a) equivalent weight; (b) height; (c) b/h ratio with respect to L for different loading.27 Variation of thickness with respect to different segments along the length (case: L=50m, w=200kN/m, seg=8) .28 Variation of thickness of web with respect to L or different segment (w=200kN/m) .29 Variation of the ℓ/L ratio with respect to different segments along the length (w=200kN/m, seg=8, all cases of L).30 Bending moment diagram and resisting moment diagram .31 Result of longitudinal stress SZ in ANSYS (1) nodal solution; (2) stress along middle top flange; (3) stress along middle bottom flange.32 Design of two-span continuous bridge a) Conventional design T1; b) Design T2; c) Proposed bridge design T3 .33 Design of closed-rectangular brdige by up-down method R4 a) Side view; b) Positive moment area; c) Negative moment area.34 Plate sizes design of steel box girder for Model 2 a) Conventional bridge T1; b) Proposed bridge T3.1 Notation of double composite cross section .2 a) Intermediate beam; b) Primary beam subject to external loading, c) Primary loaded with redundant RB .163 -x- LIST OF TABLES Table Page No.1 Comparison of characteristic in single span .2 Types of up-down construction methods.3 Comparison of cross section height and amount of material .4 Summarized the loading and composite section during the up-down construction stage .1 Summarized cross section of Model 1 for parameter study .2 Material properties of steel .3 Material properties of concrete.4 Bending stress and total reaction comparisons.1 Unit cost of steel plate (Lwin, 2002) .2 Height of steel box girder in difference type of steel grade .3 Cost of steel material in difference type of steel grade .4 Cost ratio comparisons for the homogenous grade 50 .5 Construction sequence on three-span continuous bridge .6 Construction sequence on four-span continuous bridge.1 Input variables for time-dependent creep and shrinkage models.74 - xi - Table Page No.2 Section properties of composite sections.3 Construction sequence schedule and bending moment .4 Short term stress and long term stress in sagging moment at stage 5 .5 Short term stress and long term stress in hogging moment at stage 5 .6 Stress in hogging moment at service stage .7 Stress in sagging moment at service stage.1 List of ten first eigenvalues of buckling .2 Stress in the top lateral bracing strut system .3 Coefficient of moment for uniformly loaded continuous beam over equal spans .4 Maximum values of height and thickness of web and flanges .5 Summary of variables and constraints.6 Results of optimization .7 Comparison of closed section, open section bridge designs .8 Comparison of open section bridge designs .9 Comparison of the bending stress.10 Comparison of designs of Model 2.140 - xii - CHAPTER 1 INTRODUCTION 1.1 Introduction Steel box girders have a proven high structural efficiency because of their large bending, torsional stiffness as well as rapid erection and therefore are used in a wide variety of structural applications.
However, they have comparatively big section, noise and vibration. These demerits can be reduced by using up-down construction method. Up and down construction method is a new method for bridge construction in which interior supports are lifted up and lowered down during the construction stage to improve some of the structural characteristics of the bridge system. It has been used for prestressed concrete bridges, preflex bridges and steel box-girder bridges (MANSECOREA website, 2007).
In this construction method, the separate beams are connected at interior joints with a continuity connection to get a continuous beam which reduces the beam deflection.