Retrofit Measures for Abutments Footings and Abutments, Footings ...
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Oxfam analysis and recommendations to Mars, Mondelez, and Nestle on gender equality in the cocoa sector October 31, 2014 In the spring of 2013, Oxfam’s Behind the Brands initiative launched a campaign to urge food and beverage companies to do more to ensure equal rights and treatment of women in their supply chains. The campaign focused on Mars, Mondelez and Nestle, who together source nearly 30 percent of the world’s cocoa, and urged them to step up efforts to address endemic inequality and discrimination in their cocoa supply chains. More than 100,000 people, as well as concerned investors and other groups, joined Oxfam to call on these companies to understand how women in their cocoa supply chains are faring and create aggressive action plans to increase gender equality in the production of their ingredients. By April 2013 all three companies stepped up and made commitments to conduct impact assessments within their supply chains and to publish clear action plans to address the issues raised by these impact assessments. Oxfam commended these commitments as an important step toward tackling gender inequality. Now, over a year later, Oxfam commissioned an independent evaluation of the progress companies have made in fulfilling their commitments. The evaluation provides an analysis of four gender impact assessments and action plans published by the world’s “Big Three” chocolate companies in Côte d’Ivoire (all three) and Ghana (just Mondelez). Oxfam funded this objective review of company progress to ensure an effective monitoring process of the commitments and mutual accountability for the companies involved. This evaluation is a tool to help assess whether companies are meeting their public commitments. The independent evaluation was conducted by Man-Kwun Chan 1 , a respected expert on gender issues in agricultural supply chains. Before publishing the evaluation, all three companies and Oxfam were given the opportunity to comment on a draft of the report and offer feedback on the findings. Oxfam finds the general conclusions and recommendations in the consultant’s evaluation to be sobering but encouraging. We recognize that each company has specific strengths in addressing gender equality in the cocoa supply chain and we applaud Mars, Mondelez and Nestle for taking these necessary initial steps. We recognize that all three are making significant progress with respect to: Serving as pioneers in the cocoa sector to address gender inequality in the supply chain. Delivering their impact assessments and action plans within the committed timeline. Demonstrating their commitment to women farmers and workers by designing and implementing activities and trainings in local cocoa communities where women and men can equally strengthen their capacity and agency. 1 Man-Kwun Chan is a social development and corporate social responsibility (CSR) professional with over 20 years’ experience in a wide range of sectors and roles, with substantial overseas experience in 13 countries. For the last 6 years, Man-Kwun has worked as an independent consultant specialising in improving the gender, labour and social impacts of global business operations in developing countries. Her LinkedIn profile can be found at: http://uk.linkedin.com/in/mankwunchan.
Transcript of Retrofit Measures for Abutments Footings and Abutments, Footings ...
Retrofit Measuresffor
Abutments Footings andAbutments, Footings, and FoundationsFoundations
Purposep
To describe typical retrofit measures for: Abutments Footings Piles Piles
Abutment retrofit measures
Approach slabs Anchor slabs Diaphragm walls
T h k Transverse shear keys Transverse soil anchors Soil and gravity anchors
Abutment retrofit measures
California settlement (approach) slab Design as SS
10’ min Spans soil to deck Connection FD is
FD
0
F D S a DL
µ≈0.6 Friction CoeffSa=Spectrum AccDL=Dead Load
Abutment retrofit measures New Zealand settlement slab
A l ff l it di l i t Angle offers longitudinal resistance Still have smooth approach
Abutment retrofit measures Waffle slab retrofit
2h
R i t 96h k f Resistance=.96h ksf Resistance 16” pile=40 kips ultimate
Abutment retrofit measures Anchor slab retrofit Vertical capacity is of no concern Must be securely connected to superstructurey p
Use damping ratio of 10% Longitudinal forces will reduce 20%
Abutment retrofit measures
Diaphragm overlay Diaphragm overlay Must act composite Utilize dowels to provide
shear transfer
Abutment retrofit measures Concrete transverse shear keys
Abutment retrofit measures
Concrete transverse shear keys
Abutment retrofit measures
Transverse soil anchors Lateral resistance methods:
Lateral capacity of piles Passive pressure on wingwalls Friction on bottom of footing Anchor slabs (previously discussed)
When these are not sufficient, consider soil anchors
Abutment retrofit measures Wingwall cross-tie
Abutment retrofit measures Abutment soil shear keys
-Pp=.96h ksf
Design tips
-To be fully effective:clear space=2h
-Design shear for full passive pressuref f2h -Use R=2 for flexure
-Abutment connection designed for overstrength moment
2h
h
Abutment retrofit measures
Wing overlay
Abutment retrofit measures
Wing overlay
Abutment retrofit measures
CIDH pile shear key Designed for lateral g
capacity only More effective when
fixed at top
Abutment retrofit measures
Deadman anchor Extend anchors to avoid backfill movement Embed tie rods in concrete trench for protection
Abutment retrofit measures
Deadman anchor
Abutment retrofit measuresAbutment retrofit measures
Abutment retrofit measures Soil anchors Portion of rod is not grouted for prestressing Portion of rod is not grouted for prestressing Prestress ensures anchor is solid
Abutment retrofit measures Abutment friction anchor
U ith l il ith littl ttl t Use with granular soils with little settlement 15 degree slope compresses slab as longitudinal
tmovement occurs Steel piles resist uplift
Footing retrofit measuresg Footing strengthening
F t bilit For stability Check moment at top
Footing retrofit measuresFooting retrofit measures
Footing retrofit measuresg Footing concrete overlay
U l t i ti t it Use overlay to increase negative moment capacity Use added depth to check positive moment
Footing retrofit measuresg Reinforcing splice detail
Footing retrofit measuresg Prestressing Use to help positive moment
Footing retrofit measures (step 1)g ( p ) Determine design forcesg Limit to flexural capacity of pier
Use overstrength momentg Material stronger than expected Confinement of concrete Strain hardening of steel
Increase axial load from EQ
Footing retrofit measures (step 2)g ( p )
Check OT capacity If exceeded-check stability with a rocking analysisy g y
This may eliminate retrofit requirements
Footing retrofit measures (step 3)g ( p )
Design for shear Difficult to retrofit
Increase footing depth with overlay Add prestressing bars Add vertical bars through drilled holes (must pass
bottom layer with hooks (anchors) to be effective or reduce effectiveness 50%reduce effectiveness 50%
Footing retrofit measures (step 4)g ( p )
Design for flexure Top reinforcing lacking very ofteng g y
Add overlay with steel and dowels ½ should be within thickness of footing from column
Extra depth helps positive moment Place prestress as close to column as possible
Footing retrofit measures (step 5)g ( p )
Design dowels to connect to existing concrete Should transfer shear stress at interface Use shear friction approach-friction=1.0 If used for shear strength, proper anchorage at If used for shear strength, proper anchorage at
bottom is required-(difficult to do this)
Footing retrofit measures (step 6)g ( p ) Check column-to-footing joint shear
Research shows principal failure is from joint shear Research shows principal failure is from joint shear
Footing retrofit measures (step 7)Footing retrofit measures (step 7) Overlay capacity
Strut and tie model Strut and tie model Yield line theory Easier to just make overlay thicker Example 10.1
provides Easier to just make overlay thicker provides retrofit of footing
Limiting forces transmitted to gfootings Footing link beam Objective is to force hinge in the column above j g
the link Redistribution of forces Limits shear below link Limits moment at footing
Pile to footing connectiong
Adding new piles Adding new piles Steel pipe piles filled with conc and rebar
Stiffer than H piles to resist lateral loads Stiffer than H piles to resist lateral loads Good connection to new footing
CIDH CIDH Can be drilled in low head room Very stiff for lateral loads Good connection to new footing
Pile to footing connectiong Prestress tie down
P f l d ti d Proof load tiedown Pile capacity limits
t famount of prestress
D t f ti Due to footing rotation, limited use to short columns (before fully effective-rotation may be large)may be large)
Summaryy
To describe typical retrofit measures for: Abutments Footings Piles Piles
Abutment retrofit measures
Approach slabs Anchor slabs Diaphragm walls
T h k Transverse shear keys Transverse soil anchors Soil and gravity anchors
Footing retrofit measuresg
Footing replacement Strengthening of footingsg g g Limiting forces transmitted to footings
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