Bridge Jacking Design Sample Calculation.pptx

TABLE OF CONTENTS – BRIDGE JACKING AND BLOCKING
CHAPTER 28
FILE NO. TITLE DATE
TABLE OF CONTENTS AND INTRODUCTION
28.TOC-1 Table of Contents - Chapter 28................................................................31Oct2022
28.TOC-2 Table of Contents - Chapter 28................................................................31Oct2022
28.00 Introduction - Chapter 28 ......................................................................... 31Oct2019
GENERAL INFORMATION
28.01-1 General Information and Structural Considerations .................................31Oct2019
28.01-2 Jacking Load Requirements.....................................................................30Oct2020
28.01-3 Jacking Load Requirements.....................................................................30Oct2020
28.01-4 Commercially Available Jacking Cylinders...............................................31Oct2019
28.01-5 Commercially Available Jacking Cylinders...............................................31Oct2019
NEW BRIDGE DESIGN PLANS
28.02-1 Jacking at the Beam Seat and under the Bottom Flange ........................31Oct2019
28.02-2 Jacking at the Beam Seat and under the Bottom Flange and
Jacking between Beams ..........................................................................31Oct2019
28.02-3 Check List – New Bridge Design .............................................................31Oct2019
28.02-4 Sample Jacking and Blocking Plans .......................................................31Oct2019
28.02-5 Check List – Plan Sheet........................................................................... 31Oct2019
28.02-6 Check List – Plan Sheet........................................................................... 31Oct2019
* 28.02-7 Sample Plan Sheet – Steel Girder Bridge................................................31Oct2019
* 28.02-8 Sample Plan Sheet – Steel Girder Bridge................................................31Oct2022
* 28.02-9 Sample Plan Sheet – Concrete Beam Bridge..........................................31Oct2019
MAINTENANCE AND REPAIR PLANS
28.03-1 General Information..................................................................................31Oct2019
28.03-2 General Information..................................................................................31Oct2019
28.03-3 Example Jacking Details .......................................................................... 31Oct2019
28.03-7 Check List – Maintenance and Repair Plans ...........................................31Oct2019
28.03-8 Check List – Maintenance and Repair Plans ...........................................31Oct2019
* Indicates 11 x 17 sheet; all others are 8½ x 11.
BRIDGE JACKING AND BLOCKING
TABLE OF CONTENTS - CHAPTER 28
PART 2
DATE: 31Oct2022
SHEET 1 of 2
FILE NO. 10.TOC-1

TABLE OF CONTENTS – BRIDGE JACKING AND BLOCKING
CHAPTER 28
FILE NO. TITLE DATE
SAMPLE CALCULATIONS
28.04-1 Sample Calculations.................................................................................31Oct2019
TABLE OF CONTENTS - CHAPTER 28
PART 2
DATE: 31Oct2022
SHEET 2 of 2
FILE NO. 10.TOC-2

INTRODUCTION
It is the intent of this chapter to establish the guidelines and specific requirements of the Structure
and Bridge Division for the design and detailing of bridge jacking and blocking systems. Specific
topics include jacking and blocking of existing superstructures, required jacking accommodations
for new structures, loading requirements for jacking operations, commonly used jacks, and other
issues that should be considered during the development of jacking and blocking plans.
References to the AASHTO LRFD Specifications in this chapter refer to the current AASHTO
LRFD Bridge Design Specifications, and VDOT Modifications (current IIM-S&B-80).
The practices and requirements set forth herein are intended to supplement or clarify the
requirements of the AASHTO LRFD Specifications, and to provide additional information to assist
the designer. In the event of conflict(s) between the practices and requirements set forth herein
and those contained in the AASHTO LRFD Specifications, the more stringent requirements shall
govern.
It is expected that the users of this chapter will adhere to the guidelines and requirements stated
herein.
NOTE:
Due to various restrictions on placing files in this manual onto the Internet, portions of the
drawings shown do not necessarily reflect the correct line weights, line types, fonts, arrowheads,
etc. Wherever discrepancies occur, the written text shall take precedence over any of the drawn
views.
INTRODUCTION – CHAPTER 28
PART 2
DATE: 31Oct2019
SHEET 1 of 1
FILE NO. 28.00

GENERAL INFORMATION:
Jacking and blocking methods may be employed to lift and provide temporary structural support
to bridge superstructure components for a wide variety of reasons, including:
 Replacement or modification of existing bearings
 Resetting existing or new bearings that are out of proper alignment
 Anchor bolt replacement
 Steel beam / girder end modification or replacement
 Concrete beam end repair
 Beam seat repair or reconstruction
Jacking and blocking of existing structures shall conform to the requirements of Sections 412 and
426 of the current edition of the VDOT Road and Bridge Specifications and as specified herein.
Jacking and blocking plans are required for new bridges that have
 Design Year ADT ≥ 2,000 and
 Longest span length ≥ 125’ for steel and 100’ for concrete
The District Structure and Bridge Engineers (DBE) may require jacking and blocking plans at their
discretion for other bridges.
The designers are expected to consider the guidelines herein to ensure that new designs will be
suitable to accommodate future jacking operations. The designers shall present loading
information and basic jacking requirements in the plans. They shall fully consider all jacking loads
to be placed on the structure and should analyze members as necessary to ensure that the
strength is adequate by conventional methods. If not, special notes or details should be
developed so that a method is clearly available for bidding.
STRUCTURAL CONSIDERATIONS:
The following items, but not limited to, shall be taken into account in the development of jacking
plans and procedures:
 The number and location of girders to receive jacking and blocking.
 Jacking and blocking sequences.
 All loads to be supported during jacking and blocking operations, including permanent
dead load, construction loads, and live loads.
 Specified jacking height with maximum overall and differential heights permitted.
 The size and number of jacks required to satisfy load requirements.
 The placement of jacks to ensure that the locations are accessible and adequate to
provide structural support.
GENERAL INFORMATION
STRUCTURAL CONSIDERATIONS
PART 2
DATE: 31Oct2019
SHEET 1 of 5
FILE NO. 28.01-1

 Additional temporary supports, bents, or cribbing as necessary.
 Existing conditions of the structural elements.
 Modification or strengthening of bridge members at the jacking locations as necessary.
 Stability of the structure with the jacking and blocking system at every stage.
JACKING LOAD REQUIREMENTS:
In accordance with the AASHTO LRFD Bridge Design Specifications, Section 3.4.3.1:
 The design forces for jacking in service shall not be less than 1.3 times the permanent
load reaction at the bearing, adjacent to the point of jacking.
 Where the bridge will not be closed to traffic during the jacking operation, the jacking load
shall also contain a live load reaction consistent with the maintenance of traffic plan,
multiplied by the load factor for live load.
The permanent DC dead load reaction shall include construction tolerance. The permanent DW
dead load reaction need not include future wearing surface loads.
If construction loads will be allowed on the structure during jacking operations, the magnitude and
limits shall be indicated on the plans. The construction loads including dynamic effects shall be
added with a load factor of 1.5 in accordance with the AASHTO LRFD Bridge Design
Specifications, Section 3.4.2.1.
Due to the uncertainty regarding the magnitude of live loads that may be present at a given bridge
site, full or partial closure of the bridge during jacking and blocking operations is preferred and shall
be investigated. If any portion of the bridge will be open to traffic during jacking and blocking
operations, the effect of live load and dynamic load allowance shall be considered. Since the
Strength I Limit State with HL-93 loading is calibrated for a 75-year design life, application of this
design live load may be overly-conservative. In some cases, a reduced live load based on the
current AASHTO Manual for Bridge Evaluation and VDOT IIM-S&B-86 may be appropriate.
The Hauling Permit Specialist in the VDOT Central Office shall be consulted to avoid overload
traffic during jacking and blocking operations.
The live load and applicable limit state selected to determine the required jacking loads shall be
approved by the District Structure and Bridge Engineer.
A ¼” jacking height limit shall be used. For simple span bridges, a higher jacking height may not
cause issues. However for continuous bridges, significant additional jacking forces may be
needed to jack up the girders/beams to a higher position. An excessive jacking height may also
cause damages to the structures.
Jacking and blocking plans shall include a Jacking and Blocking Data Table that identifies the
loads, load combinations, and other load requirements for the development of the jacking plan.
GENERAL INFORMATION
JACKING LOAD REQUIREMENTS
PART 2
DATE: 30Oct2020
SHEET 2 of 5
FILE NO. 28.01-2

Minimum jack capacity shall be 200% of the calculated lifting load to account for some
uncertainties.
Sample Jacking Data Table 1:
JACKING AND BLOCKING DATA TABLE
LOCATION
Girder Reactions (kips)
No. of Jacks
per Girder
Minimum
Jack Capacity,
(tons) Each
DC
Dead Load
LL+IM
Live Load
1.25(DC)+1.35(LL+IM) FL
Abutment A 69 52 157 4 2 80 +2
Pier 141 112 328 10 2 18 0+
5
Abutment B 83 64 191 4 2 10 0+
2
1. The tabulated live load corresponds with the HL-93 loading with dynamic load allowance.
2. The tabulated reactions correspond with the interior girder which controls at each substructure.
3. The jacking locations have been designed for the Strength II Limit state (Operating Level).
4. FL is the lift force needed to deflect the girder ¼” at this location, assuming all girders are jacked
simultaneously.
Sample Jacking Data Table 2:
JACKING AND BLOCKING DATA TABLE
LOCATION
Girder Reactions (kips)
No. of Jacks
per Girder
Minimum
Jack Capacity,
(tons) Each
DC
Dead Load
LL+IM
Live Load
1.30(DC) FL
Abutment A 69 - 90 4 1 90+ 4
Pier 141 - 184 10 1 190 +1
0
Abutment B 83 - 108 4 1 110 +4
1. Lanes shall be closed as necessary to ensure that jacks are not subject to traffic loading.
2. The tabulated reactions correspond with the interior girder which controls at each substructure.
3. The jacking locations have been designed for 1.3 times the permanent dead load reaction.
4. FL is the lift force needed to deflect the girder ¼” at this location, assuming all girders are jacked
simultaneously.
For new bridge designs where jacking and blocking plans are required, the following note shall be
included in the jacking and blocking plans.
The (girders) (beams) (diaphragms) (cross frames) (jacking stiffeners) (abutments) (piers) have
been evaluated at the specified jacking locations for a maximum factored reaction of ( ) kips at the
( ) Limit State. Live load (is) (is not) permitted during jacking and blocking
operations.
GENERAL INFORMATION
JACKING LOAD REQUIREMENTS
PART 2
DATE: 30Oct2020
SHEET 3 of 5
FILE NO. 28.01-3

COMMERCIALLY AVAILABLE JACKING CYLINDERS:
When developing jacking plans or identifying potential jacking locations for jacking and blocking
operations, it is important to ensure that jacking systems are readily available to accomplish the
work.
Jacking cylinders are commercially available with a wide range of sizes and capabilities.
For jacking scenarios that require tight clearances and do not require the bridge to be lifted a
significant magnitude, low height jacking cylinders (e.g. “pancake jacks”) are a good solution.
These jacks are relatively light weight and are more compact to fit into tight spaces. Since they
are more compact, low height jacking cylinders have limited available stroke and capacity.
The tabulated low height jacking cylinders below were obtained from three manufacturers,
showing each product’s properties through a range of available capacities.
LOW HEIGHT JACKING CYLINDERS (TYP)
Cylinder Retracted Extended Outside Effective
Capacity Stroke Height Height Diameter Area Weight
(tons) (in) (in) (in) (in) (in2) (lbs)
5 0.25 1.28 1.53 1.63 x 2.31 0.99 2.3
5 0.56 1.63 2.19 1.63 x 2.56 0.99 2.2
5 0.62 1.62 2.25 1.62 x 2.56 0.99 2.5
10 0.44 1.69 2.13 2.19 x 3.25 2.24 3.1
10 0.44 1.75 2.19 2.19 x 3.25 2.24 3.3
10 0.44 1.68 2.13 2.19 x 3.25 2.24 3.3
20 0.44 2.03 2.47 3.00 x 4.00 4.43 6.8
20 0.44 2.00 2.44 3.00 x 4.00 4.43 5.6
20 0.44 2.03 2.47 3.00 x 4.00 4.43 6.0
30 0.50 2.31 2.81 3.75 x 4.63 6.49 10.0
30 0.50 2.31 2.81 3.75 x 4.50 6.49 8.6
30 0.50 2.31 2.81 3.75 x 4.50 6.49 8.5
50 0.63 2.63 3.25 4.50 x 5.50 9.62 15.0
50 0.63 2.63 3.25 4.50 x 5.50 9.62 14.0
50 0.62 2.62 3.25 4.50 x 5.50 9.62 14.3
75 0.63 3.13 3.75 5.50 x 6.50 15.90 25.0
75 0.63 3.13 3.75 5.53 x 6.50 15.90 23.3
75 0.62 3.13 3.75 5.50 x 6.50 15.90 24.5
100 0.63 3.38 4.00 6.00 x 7.00 19.63 32.0
100 0.63 3.38 4.00 6.00 x 7.00 19.64 30.0
100 0.62 3.38 4.00 6.00 x 7.00 19.63 31.0
150 0.63 3.94 4.56 7.50 x 8.50 30.68 58.0
150 0.56 4.00 4.56 7.50 x 8.50 30.68 52.0
150 0.56 3.93 4.50 7.50 x 8.50 30.66 50.5
GENERAL INFORMATION
COMMERCIALLY AVAILABLE JACKING CYLINDERS
PART 2
DATE: 31Oct2019
SHEET 4 of 5
FILE NO. 28.01-4

For jacking scenarios that are unconstrained by clearances or require a bridge element to be
jacked a significant magnitude (more than ½”), a general purpose cylinder can be considered.
The tabulated general purpose jacking cylinders below were obtained from two manufacturers,
showing the smallest and largest cylinder at each available capacity. The jack dimensions vary
significantly, and depend upon the capacity and stroke required.
GENERAL PURPOSE JACKING CYLINDERS (MAX/MIN)
Cylinder Retracted Extended Outside Effective
Capacity Stroke Height Height Diameter Area Weight
(tons) (in.) (in.) (in.) (in.) (in2) (lbs.)
10 6.25 11.69 17.94 3.00 2.23 22.0
10 12.00 18.00 30.00 2.88 2.23 31.0
25 6.00 9.38 15.38 4.00 6.49 32.0
25 14.50 21.63 36.13 4.00 6.51 64.0
50 2.00 5.44 7.44 5.00 11.05 30.0
50 20.13 28.88 49.00 5.00 11.06 150.0
75 6.13 13.69 19.81 5.75 15.92 92.0
75 13.13 20.69 33.81 5.75 15.92 150.0
100 6.00 10.56 16.56 6.38 19.63 90.0
100 20.13 30.50 50.63 6.88 20.63 260.0
150 2.00 7.00 9.00 9.00 30.68 117.0
150 32.13 43.94 76.06 8.00 30.71 525.0
200 2.00 8.00 10.00 10.00 41.28 184.0
200 48.00 60.13 108.13 9.75 44.21 1065.0
300 2.00 11.50 13.50 12.00 60.13 277.0
300 48.00 61.13 109.13 12.25 70.93 1720.0
400 2.00 11.50 13.50 14.00 86.59 455.0
400 48.00 63.19 111.19 14.13 95.09 2162.0
500 2.00 12.62 14.62 16.00 103.87 627.0
500 48.00 64.75 112.75 15.63 113.15 2700.0
600 2.00 13.50 15.50 17.50 122.71 655.0
600 12.00 23.50 35.50 17.50 122.71 1273.0
800 2.00 14.44 16.44 18.00 165.13 997.0
800 12.00 24.44 36.44 18.00 165.13 1644.0
1000 2.00 16.13 18.13 21.00 201.06 1523.0
1000 12.00 26.13 38.13 21.00 201.06 2423.0
It is noted that with multiple jacking iterations, low height jacking cylinders can still be used in
cases that require a bridge to be lifted a distance greater than the available stroke for a given
jack.
GENERAL INFORMATION
COMMERCIALLY AVAILABLE JACKING CYLINDERS
PART 2
DATE: 31Oct2019
SHEET 5 of 5
FILE NO. 28.01-5

NEW BRIDGE DESIGN PLANS:
When developing new bridge plans, the designer shall use the guidelines herein to ensure that
new designs will be suitable to accommodate future jacking operations.
JACKING AT THE BEAM SEAT AND UNDER THE BOTTOM FLANGE:
In most circumstances, the preferred jacking method involves jacking from the beam seat, directly
under the bottom flange on the centerline of beam. This portion of a beam often already has
adequate capacity to withstand the full reaction of the beam. Jacking from this location can also
reduce or eliminate the need for additional temporary supports, bents, or cribbing.
The designer shall take into account the following factors for new design:
 Jacking at this location is feasible in cases where the height of the bearing assembly can
accommodate the jacking cylinder in its collapsed state with shims and load distribution
plates as necessary. The designer must consider the grade (vertical profile) of the bridge
when determining the height available for jacking.
 The accessibility of the jacking location should be evaluated to ensure that the intended
operation can be completed with jacking and blocking in place. The designer should
consider whether there is adequate space to manipulate the bearing.
 When designing beam seats at abutments and piers, the designer shall provide adequate
offset from the edge of sole plate to the edge of seat for future jacking operations. The
minimum edge distance from the jacking system is 3 inches.
 The seat should be evaluated in accordance with AASHTO 5.6.5 to determine whether
adequate concrete bearing resistance is provided for the selected jacking loads. If not,
additional seat reinforcing may be required to resist bursting forces in accordance with
AASHTO 5.9.5.6. Multiple jacks or load distribution plates may be used to reduce the
maximum reaction, provided that there is adequate height available under the flange.
 The designer should consider whether the recommended jacking location would apply an
eccentric loading to the substructure that may warrant explicit analysis when designing
the abutment or pier reinforcing and foundation.
 For steel beams or plate girders, the webs should be detailed with jacking stiffeners
located at suggested jacking locations.
o The jacking stiffeners shall be designed in accordance with AASHTO 6.10.11.2
for bearing stiffeners. Depending upon the beam/girder design, the webs may be
adequate for concentrated loads without bearing stiffeners; however, jacking
stiffeners are still recommended as an indication that the location has been
engineered to accommodate jacking operations.
o To provide welding access, jacking stiffeners shall maintain a minimum spacing
of 8” or 1½ times the plate width to adjacent stiffeners or connection plates.
o The Designer shall determine whether the presence of jacking stiffeners would
impede installation of end cross frames or diaphragms. Adequate space must be
provided to allow these one-piece members to swing into place.
BRIDGE JACKING AND BLOCKING PART 2
JACKING AT BEAM SEAT AND UNDER BOTTOM FLANGE
DATE: 31Oct2019
SHEET 1 of 11
FILE NO. 28.02-1

JACKING AT THE BEAM SEAT AND UNDER THE BOTTOM FLANGE (Continued):
 The effect of skew must be considered when applicable to ensure that jacking locations
along the centerline of beam correlate with the intended locations on the seats.
 In cases of beams with varying depths, e.g. haunched beam, the distance from the edge
of the sole plate to the transition shall be a minimum of 12 inches to accommodate
jacking.
JACKING BETWEEN BEAMS:
For some cases, it may not be possible to provide jacking accommodations directly under a beam
at the beam seat. For instance, depending upon the bearing height, there may not be adequate
space available to install even a low-height jacking cylinder of adequate capacity. In such cases,
providing jacking accommodations between beams to a cross frame or diaphragm can be a
solution.
The following factors should be considered for new designs:
 When steel cross frames are present, the designer should evaluate the cross frame
members to determine the most beneficial load path and point of contact. The top chord
in an end diaphragm is typically a channel and may provide a better point of contact.
Steel angles shall not be jacked directly.
 When a jacking location is specified to a cross frame or diaphragm, the designer shall
evaluate all members, including all bolted and welded connections, to determine their
adequacy for the jacking forces.
 It may be beneficial to substitute a W-shape for the top chord of a cross frame or use
diaphragm to provide additional capacity. Alternatively, it may be appropriate to relocate
or replace a cross frame to allow a more suitable member to attach to the bearing
stiffeners.
 As with new steel beams and plate girders, the webs of members to be jacked should be
detailed with jacking stiffeners. Regardless of whether they are required for capacity,
jacking stiffeners are recommended as an indication that the location has been
engineered to accommodate jacking operations.
 Jacking between beams typically needs a jacking column or significant blocking.
 Jacking from the substructure footing may be cost effective for some cases.
 A preliminary design of temporary supports or jacking columns may be warranted to
confirm feasibility.
BRIDGE JACKING AND BLOCKING PART 2
JACKING BETWEEN BEAMS
DATE: 31Oct2019
SHEET 2 of 11
FILE NO. 28.02-2

CHECK LIST – NEW BRIDGE DESIGN:
Regardless whether jacking and blocking plans are required:
1. There is an adequate offset from the edge of sole plate to the edge of beam seat to
accommodate the jacking cylinder and load distribution plates.
2. There is adequate space to manipulate the bearing with jacking and blocking in place.
3. The effect of skew or curvature has been considered when applicable to ensure that
jacking locations along the centerline of beam correlate with the intended locations on the
seats.
4. For beams with varying depths, the distance from the edge of the sole plate to the
transition is a minimum of 12 inches to accommodate jacking.
5. For situations where jacking from the bottom flange is not feasible or economical,
jacking accommodations have been provided at another location, such as below a cross
frame or diaphragm.
6. The height of the bearing assembly can accommodate the jacking cylinder in its
collapsed state with shims and load distribution plates.
When jacking and blocking plans are required:
7. The plans clearly indicate the locations that are designed for future jacking.
8. A note has been included to indicate the anticipated jacking loads, design limit state
and live load requirements for which the jacking locations have been evaluated.
9. The substructure unit including the beam seat has been designed to resist the
anticipated jacking loads.
10. Steel beams or plate girders are detailed with jacking stiffeners located at suggested
jacking locations when jacking and blocking plans are required.
11. Jacking stiffeners are designed to resist the anticipated jacking loads, meet the
minimum spacing requirements and provide adequate space for cross frame or diaphragm
installation.
12. The design will accommodate future jacking operations and all members have been
evaluated, including all bolted and welded connections, to determine their adequacy for the
jacking forces.
13. If required, a preliminary design of temporary supports or jacking columns has been
performed to confirm feasibility.
CHECK LIST
PART 2
DATE: 31Oct2019
SHEET 3 of 11
FILE NO. 28.02-3

SAMPLE JACKING AND BLOCKING PLANS:
This section includes sample jacking and blocking plan sheets with a checklist for completing
them.
Jacking locations should be incorporated in the framing plan for steel girder bridge or erection
diagram for concrete beam bridge.
One sample jacking and blocking for a steel girder bridge and one for a concrete beam bridge are
provided. These sheets are only for information purpose. The designer needs to modify the
details (or develop other details) to fit their project.
The jacking and block plans shall provide, but not limited to, the following information: locations of
jacking points, jacking and blocking data table, jack information, blocking information, jacking and
blocking sequence, materials requirements, pertinent details and notes.
Information placed in blocks on the sample deck plan sheets is for designer’s information only
and is not to be placed on the deck plan sheet.
SAMPLE JACKING AND BLOCKING PLANS
PART 2
DATE: 31Oct2019
SHEET 4 of 11
FILE NO. 28.02-4

CHECK LIST FOR JACKING AND BLOCKING PLAN SHEET:
1 Framing plans shall be drawn to a scale of sufficient size to fit the full size sheet and be
legible when reduced to half-size. Drawings drawn to a scale other than those listed in
File No. 01.04 shall be indicated as not to scale.
2 Show skew angle(s) if applicable. For a 0°skew, show as 90°to C
L / B
L .
3 Label C
L/ B
L of roadway. This designation should match that shown on the title sheet.
4 At abutments, label line thru center of bearings. Provide station.
5 Label C
L pier and line thru center of bearings if applicable. Provide station.
6 Dimension span length(s) and label span(s).
7 Label girders.
8 Dimension girder spacing.
9 Dimension the spacing of cross frames or diaphragm.
10 Dimension the spaces of stiffeners.
11 Label the bearing stiffeners, transverse stiffeners or jacking stiffeners.
12 Label the cross frames, intermediate diaphragm or closure diaphragm.
13 Label the cross frame connector plates.
14 Dimension location(s) of the bolted field splices.
15 Label bolted field splices.
16 Label jacking location.
17 Label FRAMING PLAN.
18 Provide North Arrow.
19 Pertinent details.
20 Jacking and blocking data table.
21 For instructions on completing the title block, see File No. 03.03.
22 Notes.
PART 2
DATE: 31Oct2019
SHEET 5 of 11
FILE NO. 28.02-5

CHECK LIST FOR JACKING AND BLOCKING PLAN SHEET (Continued):
23 For instructions on completing the project block, see File No. 04.01.
24 For instructions on developing the CADD sheet number, see File Nos. 01.01-6 and
01.14-4.
25 For instructions on completing the block for sealing, signing and dating this sheet, see
File Nos. 01.16-1 thru -5
PART 2
DATE: 31Oct2019
SHEET 6 of 11
FILE NO. 28.02-6

MAINTENANCE AND REPAIR PLANS:
There may be many restraints for jacking and blocking for maintenance and repair work. If
possible, it is preferred jacking from the beam seat and directly under the bottom flange on the
centerline of beam. If the beam seat is too narrow or the distance from the beam seat to the
bottom flange of the beam is too small to accommodate a low height jack, the designer should
investigate the options jacking from the substructure footing or using temporary support structure
to jack the beam under the bottom flange. Some concepts will be provided in the subsequent
sections.
If jacking under the bottom flange is not feasible, jacking between the beam and to cross frames
and diaphragms can be a solution.
Jacking directly to the deck slab is prohibited.
The designer should consider the following, but not limited to, factors in design of the jacking and
blocking plans.
 The accessibility of the jacking location should be evaluated to ensure that the intended
operation can be completed with jacking and blocking in place. The designer should
consider whether there is adequate space to manipulate the bearing.
 Temporary blocking or jacking stiffeners are needed for jacking steel beam under the
bottom flange.
 The seat should be evaluated in accordance with AASHTO 5.6.5 to determine whether
adequate concrete bearing resistance is provided for the selected jacking loads. If not,
multiple jacks or load distribution plates may be used to reduce the maximum reaction.
 The designer should investigate the effects of jacking and blocking to the entire
superstructure, especially stability.
 The designer should consider whether the recommended jacking location would apply an
eccentric loading to the substructure that may warrant explicit analysis when designing
the abutment or pier reinforcing and foundation.
 The effect of skew must be considered when applicable to ensure that jacking locations
along the centerline of beam correlate with the intended locations on the seats.
 When jacking to cross frame or diaphragm, the designer should evaluate the cross frame
members to determine the most beneficial load path and point of contact. The top chord
in an end diaphragm is typically a channel and may provide a better point of contact. The
designer shall evaluate all members, including all bolted and welded connections, to
determine their adequacy for the jacking forces.
 Steel angles shall not be jacked directly.
PART 2
DATE: 31Oct2019
SHEET 1 of 8
FILE NO. 28.03-1

 It may be beneficial to substitute a W-shape for the top chord of a cross frame or use
diaphragm to provide additional capacity. Alternatively, it may be appropriate to relocate
or replace a cross frame to allow a more suitable member to attach to the bearing
stiffeners.
 Jacking between beams typically needs a jacking column or significant blocking.
 A preliminary design of temporary supports or jacking columns may be warranted to
confirm feasibility.
PLAN REQUIREMENTS:
Maintenance and repair plans that require jacking and blocking should include a title sheet (Plan
and Elevation), typical section and jacking details sheets sufficient to describe the overall scope
of work along with a summary of estimated quantities and other pertinent data.
Plans should clearly depict all utilities on or adjacent to the bridge. The designer shall coordinate
with the District Utilities Engineer if any utilities will be impacted by the jacking operations.
Bridge elements and appurtenances that might be damaged due to differential movement should
be checked to determine if they must be disconnected prior to jacking operations. These features
may include expansion joint elements, metal railings and utilities.
Plans should include a construction sequence outlining the suggested steps necessary to
complete the work.
Plans shall include all applicable loading requirements and tables as specified in File No. 28.01-2
and 28.01-3.
The designer shall consider maintenance of traffic in the design and ensure adequate
coordination with the construction sequence and proposed lane closures. A maintenance of traffic
plan shall be included in the jacking and blocking plans.
The following notes should be included in the regular maintenance and repair plans that require
jacking and blocking. The wording should be changed or other notes added wherever they are
not adequate.
JACKING AND BLOCKING NOTES:
The Contractor shall develop a plan and supporting calculations for jacking, blocking, and
supporting beams. Unless approved by the Engineer in writing, all jacks and temporary support
systems shall be designed to sustain traffic loadings, dead load, temporary construction loads,
and all other anticipated loading during work requiring the jacking and blocking of beams. The
design shall be in accordance with the current AASHTO LRFD Bridge Design Specifications, and
VDOT Modifications, unless noted otherwise. The plans and calculations shall be signed and
sealed by a Professional Engineer holding a valid license to practice engineering in the
Commonwealth of Virginia. The cost of preparing the plan and calculations shall be included in
the price bid for Jacking and Blocking.
PART 2
DATE: 31Oct2019
SHEET 2 of 8
FILE NO. 28.03-2

Beams to be jacked and blocked shall not be jacked more than ¼ inch or as directed by the
Engineer. The difference in elevation between adjacent beams during jacking and blocking shall
not be greater than ⅛ inch.
The Contractor shall monitor the jacking procedure to ensure that jacking does not cause damage
at any location in the spans. If there is any evidence of damage or unusual situation occurring
during the jacking operations at any location along the span, the Contractor shall take corrective
actions and notify the Engineer immediately.
The Contractor shall be responsible for any damage to the structure caused by jacking. No
structural elements shall be removed from the existing structure without prior approval from the
Engineer.
The jacks and the jacking supports shall be straight, plumb and placed at locations of level and
sound concrete.
SAMPLE JACKING DETAILS:
The jacking and blocking plan for maintenance and repair work may vary greatly from project to
project. The following conceptual details may provide some possible ways that the proposed work
can be accomplished. The designer should modify the details to fit the project.
SAMPLE JACKING DETAILS
PART 2
DATE: 31Oct2019
SHEET 3 of 8
FILE NO. 28.03-3

Jacking Under Beam from the Top of Abutment Footing
Member sizes are for illustration purposes only
Actual sizes and dimensions are to be determined by design.
PART 2
DATE: 31Oct2019
SHEET 4 of 8
FILE NO. 28.03-4

Jacking under Beam from Temporary Support at Pier
PART 2
DATE: 31Oct2019
SHEET 5 of 8
FILE NO. 28.03-5

Jacking between Beams to Cross Frames
Member sizes are for illustration purposes only
Actual sizes and dimensions are to be determined by design.
PART 2
DATE: 31Oct2019
SHEET 6 of 8
FILE NO. 28.03-6

CHECK LIST FOR MAINENANCE AND REPAIR PLANS:
Regardless whether jacking and blocking plans are required:
1. Plans include a title sheet (Plan and Elevation), typical section and jacking details sheets
sufficient to describe the overall scope of work along with a summary of estimated quantities
and other pertinent data.
2. The live load requirements and applicable limit state selected to determine the required
jacking loads has been approved by the District Structure and Bridge Engineer.
3. All loading information required for jacking and blocking operations, including
permanent dead load, construction loads, live loads, design limit state and appropriate load
factors have been included in the Jacking Data Table. If construction loads will be allowed on
the structure during jacking operations, the magnitude and limits are indicated on the plans.
4. Plans include appropriate notes as indicated in File No. 28.03-1.
5. The responsibilities of the Contractor are clearly stated.
6. Plans include a “construction sequence” outlining the suggested steps necessary to
complete the work.
7. Plans clearly show the type of repair work that is required and indicate the jacking
requirements that are necessary to accomplish the work. The intended repair operation can
be completed with jacking and blocking in place.
8. The plans identify the number and location of girders to receive jacking and blocking.
The Jacking Data Table includes the minimum jack capacity and number of jacks required to
satisfy the load requirements.
9. Plans specify jacking height with maximum overall and differential heights permitted.
10. Plans clearly depict all utilities on or adjacent to the bridge and all utilities that will be
impacted by the jacking operations have been identified.
11. _ Bridge elements and appurtenances such as expansion joints, metal railings and
utilities that might be damaged due to differential movement have been checked to determine
if they must be disconnected prior to jacking operations.
12. The effect of skew or curvature has been considered when applicable to ensure that
jacking locations along the centerline of beam correlate with the intended locations on the
seats.
13. The substructure unit including the beam seat has been checked to resist the
anticipated jacking loads.
CHECK LIST
PART 2
DATE: 31Oct2019
SHEET 7 of 8
FILE NO. 28.03-7

CHECK LIST FOR MAINENANCE AND REPAIR PLANS (CONT.):
14. There is adequate space to manipulate the bearing with jacking and blocking in place.
15. If required, details are provided for the modification or strengthening of bridge members
at the jacking locations.
16. _ If required, a preliminary design of temporary supports or jacking columns has been
performed to confirm feasibility.
17. Maintenance of traffic has been considered in the design and has been coordinated with
the construction sequence and proposed lane closures.
18. The existing structure can be safely jacked using conventional methods. If not, a
suggested method based on an analysis of all affected members has been included and the
proposed jacking locations are identified.
CHECK LIST
PART 2
DATE: 31Oct2019
SHEET 8 of 8
FILE NO. 28.03-8

SAMPLE CALCULATIONS:
The sample calculations demonstrate some of the typical items that must be addressed for a
typical jacking and blocking scenario. The designer shall check other structural elements, such as
superstructure, substructure and so forth, to ensure the jacking and blocking plans to be
developed properly.
Design Specifications: AASHTO LRFD Bridge Design Specifications, 8th Edition, 2017.
Problem Statement:
During the course of construction of a continuous steel plate girder bridge, elastomeric expansion
bearings have been found to be misaligned. The deck has been placed, but the bridge is not yet
open to traffic. The plate girders were not fabricated with jacking stiffeners at the pier.
Develop a jacking plan that would allow the contractor to lift the girder from under the bottom
flange at the pier to allow the bearing to be reset, or replaced if necessary.
Elastomeric bearing dimensions = 22”W x 20”L x 4”H
Beveled sole plate dimensions = 36”W x 22”L x 1⅛” at center line of bearing
SAMPLE CALCULATIONS
PART 2
DATE: 31Oct2019
SHEET 1 of 9
FILE NO. 28.04-1

The following unfactored dead load reactions are available from the analysis:
Girder (including secondary members) 42 kips
8½” Concrete Deck 65 kips
Haunch 3 kips
20 psf Construction Tolerance 12 kips
CPSR Railings 10 kips
Total Dead Load (DL) Reaction 132 kips
SAMPLE CALCULATIONS
PART 2
DATE: 31Oct2022
SHEET 2 of 9
FILE NO. 28.04-2

Determine Required Jacking Force and Select Jacking Cylinders:
Since the bridge is not yet open to traffic, no live loads need to be considered. The Contractor
will be required to ensure that no construction loads are present during jacking operations.
Proceed using DC dead loads only.
Per AASHTO 3.4.3.1, the design forces for jacking shall not be less than 1.3 times the permanent
load reaction at the adjacent bearing.
Factored DL reaction = 1.3*132 kips = 172 kips.
The lift force FL to deflect the girder ¼” at the location is calcuated as 10 kips.
Minimum jack capacity shall be 200% of the factored DL reaction plus the left force FL..
Minimum jack capacity = 2*(172 kips +10 kips) = 364 kips = 182 tons
Due to the limited height available under the flange for jacking operations, a low-height jacking
cylinder will be required. For this reason, two 100-ton capacity jacking cylinders will be used.
Minimum jack capacity = 182 tons / 2 = 91 tons per jack , use 100 tons.
The selected low-height jacking cylinder has the following properties:
 Capacity 100 tons OK, adequate for the required load
 Stroke ⅝” Verify that stroke > pad compression + ¼” max
 Retracted Height 3⅜” Verify that jacking assembly will fit
 Extended Height (PadHt) 4”
 Outside Diameter 6” x 7”
 Bore Diameter 5”
 Effective Area 19.63 in2
 Weight 32 lbs
The compressive deflection of the elastomeric bearing pad can be determined in accordance with
AASHTO 14.7.6.3.3. For the purpose of this example, the maximum permissible compressive
strain of 9% is applied to the total bearing height. This is conservative as this limit includes
instantaneous live load (not present for this jacking scenario) and in actuality would only apply to
the thickness of elastomer.
stroke capacity, OK
With 1’-4” of pier seat available for jacking, both jacks can be located at 1’-6” offset from the
centerline of bearing on the uphill side of the 3% vertical profile. This allows more clearance for
the contractor to install the jacks and baseplates, and to remove the pad without conflict.
SAMPLE CALCULATIONS
PART 2
DATE: 31Oct2022
SHEET 3 of 9
FILE NO. 28.04-3

Check Concrete Bearing:
With close proximity of jacks to each other and the edge of pier cap, assume the notional loaded
area A2 equal the loaded area A1 with uniform bearing as an initial assumption for sizing the
jacking baseplate.
[AASHTO 5.6.5]
Where per baseplate
per initial assumption
[AASHTO 5.5.4.2]
Try using a 10” x 10” steel baseplate, , and investigate A2.
The notional loaded area A2 is determined at a level beneath the loaded surface A1 as measured
by projecting the loads at a 2:1 slope as shown below.
The modification factor, m, is calculated two ways depending upon whether the loaded area is
subject to uniformly or non-uniformly distributed bearing stresses. Since two jacking cylinders are
required at a close spacing, let’s evaluated the concrete bearing requirements in two cases:
SAMPLE CALCULATIONS
PART 2
DATE: 31Oct2019
SHEET 4 of 9
FILE NO. 28.04-4

Analysis Case 1 – Determine A2 and m assuming uniformly distributed bearing stress.
per baseplate
[AASHTO 5.6.5-3]
required per jack, OK
Analysis Case 2 – Determine A2 and m assuming non-uniformly distributed bearing stress.
per baseplate
[AASHTO 5.6.5-4]
required per jack, OK
SAMPLE CALCULATIONS
PART 2
DATE: 31Oct2019
SHEET 5 of 9
FILE NO. 28.04-5

Since the concrete bearing is adequate using either analytical approach, let’s proceed using the
assumption of uniform bearing stress to design the baseplate thickness.
Check Steel Baseplate in Flexure and Shear:
In order to provide the uniform bearing on concrete, the 10” x 10” baseplate must transmit this load
through flexure and shear. Try using a 1-inch thick baseplate with Grade 50 steel.
max
AASHTO 6.12.2.2.7
Where
AASHTO 6.5.4.2
therefore, increase plate thickness.
Try using a 1¼” thick baseplate with Grade 50 steel.
AASHTO 6.12.2.2.7
Where
OK.
SAMPLE CALCULATIONS
PART 2
DATE: 31Oct2019
SHEET 6 of 9
FILE NO. 28.04-6

Verify baseplate shear capacity based on shear yield strength:
max
per inch AASHTO 6.10.9.2
AASHTO 6.5.4.2
OK.
Check that the jacks will fit beneath flanges with baseplates and shims to prevent marring the
bottom flange (assume 1/4” min.), accounting for the 3% vertical profile:
with jacks retracted.
Uphill Side: OK
Downhill Side: No good.
Use 10” x 10” x 1.25” baseplates with Grade 50 steel, jacking on the uphill side of the pier.
Design Jacking Columns:
Since there are no jacking stiffeners present at the jacking location, a load path must be provided
to prevent the jacking loads from damaging the plate girder.
If the jacking plan required only one jack to be used, the steel web could be evaluated for the
concentrated load per AASHTO Appendix D6.5 – Concentrated Loads Applied to Webs Without
Bearing Stiffeners.
If adequate capacity were available, then no modification for jacking operations would be
necessary. If the capacity were not adequate, temporary or permanent jacking stiffeners could be
designed and installed.
For this example, two jacks are required, which prevents the jacking forces from being aligned
with the girder web. To avoid reliance on the bottom flange to act in flexure, jacking columns will
be designed to provide a load path from the top of bottom flange to the bottom of top flange. Any
contribution from the girder web will be neglected for conservatism.
Try Schedule 40 Pipe, Pipe 6” Standard Weight, Grade 50 steel.
 Outside Diameter, D = 6.63 in
 Inside Diameter, Di = 6.07 in
 Nominal Wall Thickness, tn = 0.280 in
 Design Wall Thickness, tdes = 0.261 in
 Area, A = 5.20 in2
 Radius of gyration, r = 2.25 in
SAMPLE CALCULATIONS
PART 2
DATE: 31Oct2019
SHEET 7 of 9
FILE NO. 28.04-7

Check slenderness for elastic flexural buckling as a primary member:
Where assuming pinned-pinned
girder web
therefore, the jacking columns are not slender.
Check slenderness for local buckling:
therefore, the jacking columns are not slender.
Elastic Critical Buckling Resistance:
Nominal Yield Resistance:
Nominal Compressive Resistance:
therefore,
Factored Compressive Resistance:
for axial compression, steel only
OK
Use Schedule 40 Pipe, Pipe 6” Standard Weight, Grade 50 steel.
AASHTO 6.9.3
AASHTO 4.6.2.5
AASHTO 6.9.4.2.1
AASHTO 6.9.4.1.2
AASHTO 6.9.4.1.1
AASHTO 6.9.4.1.1
AASHTO 6.9.4.1.1
AASHTO 6.5.4.2
AASHTO 6.9.2.1
PART 2
DATE: 31Oct2019
SAMPLE CALCULATIONS SHEET 8 of 9
FILE NO. 28.04-8

PART 2
DATE: 31Oct2019
SAMPLE CALCULATIONS SHEET 9 of 9
FILE NO. 28.04-9

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