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ST0301A-SP100924 (2) (1/27/2011) Keith Marvin - Bethel Road - Response to Bridge Contractor's DetailPage 1 From: Caleb Thornhill <bct@freese.com> To: Keith Marvin <kmarvin@coppelltx.gov> CC: Chris Poteet <cjp@freese.com>, Tony Diaz <AD@freese.com>, CPL03243 <CPL0... Date: 9/24/2010 11:45 AM Subject: Bethel Road - Response to Bridge Contractor's Detail Attachments: Coppell Wall Reinforcing.pdf; Coppell Wall Stability (2).pdf Keith, Below is the response to Bridge Contractor's south retaining wall fix. It's our opinion, based on the information received, that the detail is not adequate and it's recommended that the detail, already provided, be implemented. Feel free to forward this on to Steve with North Texas Bridge so that he can respond to any information provided. Like we discussed on the phone, please review and provide any comments or questions you might have. I will be available via cell phone # 214-952-9562, or you can contact Tony directly at #817-735-7265. B. Caleb Thornhill, P.E. Freese & Nichols, Inc. 214-217-2282 The reason we proposed the fix that we sent earlier was: 1. Although we used the TxDOT standard design for the wall, once we found out that the footing and wall had been constructed opposite what was shown, we used a computer retaining wall program, Retain Pro, to analyze the "as built" configuration. We determined that the heel width needed to be that shown on the drawings in order to have sufficient soil weight to have an adequate factor of safety against overturning. Once we increased the heel width, we achieved adequate factor of safety against overturning. 2. In addition, the vertical reinforcing placed in the front of the existing wall (which was now the back) was half of what was required which necessitated an additional new wall in back of what was already there. 3. The proposed reinforcing in the heel is shown as #3@15" while our calcs show the need for #5@12". In addition, I don't think we will get composite action from the 6" slab. 4. The calculated maximum bearing pressure for the proposed fix is 3183 psf while the allowable maximum bearing pressure is only 2500 psf. 5. We then proceeded to modify the wall to provide adequate factors of safety. 6. We are attaching the Retain Pro files analyzing the Contractors' proposed fix. The wall redesign submitted by the Contractor does not address the issues above. One more detail shown on the proposed fix is that the height of the wall is 7'3" measured from the top of the footing, not 7' from the bottom of the footing as shown on the Contractors' submittal. As I mentioned earlier, the calculations and parameters for that redesign were not made available to us. We were not asked for our design information either. It is my professional opinion that the fix submitted by the Contractor is inadequate and we cannot approve it. I did point out in my previous email (attached) that another engineer can supplant an engineers' design with his own and thereby become responsible for the whole wall. We do not recommend this action to the City. (1/27/2011) Keith Marvin - Bethel Road - Response to Bridge Contractor's DetailPage 2 Tony Diaz, P.E. TX #3713 Please consider the environment before printing this message. ________________________________ This electronic mail message is intended exclusively for the individual or entity to which it is addressed. This message, together with any attachment, may contain the sender's organization's confidential and privileged information. The recipient is hereby notified to treat the information as confidential and privileged and to not disclose or use the information except as authorized by sender's organization. Any unauthorized review, printing, retention, copying, disclosure, distribution, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this message in error, please immediately contact the sender by reply email and delete all copies of the material from any computer. Thank you for your cooperation. Page: _____ Freese and Nichols, IncBuilt Wall-Contractor's Fix_ Title : Job #Dsgnr:Date: CPL03243MMTAUG 26,2010 : 4055 International Plaza Description.... Suite 200 Fort Worth, TX 76109 This Wall in File: T:\St\CPL03243\coppell retaining walls.rp5 Retain Pro 9 © 1989 - 2009 Ver: 9.09 8119 Cantilevered Retaining Wall Design Code: AASHTO LRFD Registration #: RP-1167205 RP9.09 Licensed to: Erin Rider CriteriaSoil Data =Allow Soil Bearing=psf 3,000.0 Retained Height 6.75ft Equivalent Fluid Pressure Method Wall height above soil=ft 0.00 55.0 Heel Active Pressure=psf/ft Slope Behind Wall= 0.00: 1 Toe Active Pressure= 0.0psf/ft Height of Soil over Toein 0.00Passive Pressure=psf/ft 450.0 = Soil Density, Heel=pcf 110.00 0.0 Water height over heel=ft Soil Density, Toe 110.00pcf = Footing||Soil Friction= 0.460 Soil height to ignore for passive pressure= 0.00in Thumbnail Surcharge LoadsLateral Load Applied to Stem Adjacent Footing Load Surcharge Over HeelpsfAdjacent Footing Load= 0.0lbs = 240.0 Lateral Load=1,878.8#/ft NOT Used To Resist Sliding & Overturning Footing Width= 0.00ft = 10.00ft ...Height to Top Surcharge Over Toepsf= 0.0 Eccentricity= 0.00in ...Height to Bottom= 9.00ft NOT Used for Sliding & Overturning Wall to Ftg CL Dist= 0.00ft The above lateral load has been increased 2.17 Footing TypeLine Load Axial Load Applied to Stem by a factor of Base Above/Below Soil = 0.0ft xial Dead Load 0.0lbs A = at Back of Wall Wind on Exposed Stempsf 0.0 = xial Live Load 0.0lbs A = Poisson's Ratio 0.300= xial Load Eccentricity 0.0in A = Stem Construction Top Stem Design Summary As < Min % Wall Stability RatiosDesign Height Above Ftg ft= 0.00 = Overturning 0.41UNSTABLE! Wall Material Above "Ht"=Concrete 0.59UNSTABLE! Sliding= Thickness= 12.00 Rebar Size=# 5 Rebar Spacing=15.00 Total Bearing Load= 3,606lbs ...resultant ecc.= 90.53in Rebar Placed at=Edge Resultant Exceeds Ftg. Width! Design Data Soil Pressure @ Toe= 0psf OK fb/FB + fa/Fa= No Good Soil Pressure @ Heel= 0psf OK Total Force @ Section= 5,365.2lbs 3,000 llowable=psf A Moment....Actual= 27,233.1ft-# Soil Pressure Less Than Allowable Moment.....Allowable= 11,142.5 CI Factored @ Toe= 0psf A Shear.....Actual= 61.9psi CI Factored @ Heel= 0psf A Shear.....Allowable= 90.0psi Footing Shear @ Toe= 2.2psi OK Wall Weight= 150.0 Footing Shear @ Heel = 15.6psi OK Rebar Depth 'd'= 10.19in llowable= 75.0psi A LAP SPLICE IF ABOVE= 12.00in (Vertical Component NOT Used) Sliding Calcs LAP SPLICE IF BELOW= in Lateral Sliding Force 4,740.5lbs = HOOK EMBED INTO FTG 26.48= in less 100% Passive Force= 1,139.1lbs - Masonry Data less 100% Friction Force= 1,658.6lbs - f'm=psi lbs NG dded Force Req'd= 1,942.9 A Fs=psi ....for 1.5 : 1 Stability= 4,313.1lbs NG Solid Grouting= = Modular Ratio 'n' Short Term Factor= Equiv. Solid Thick. = Load Factors Masonry Block Type=Medium Weight Building CodeAASHTO LRFD =SD Masonry Design MethodA Dead Load 1.300 Concrete Data Live Load 2.170 f'c= 3,600.0psi Earth, H 1.690 Fy= 60,000.0psi Wind, W 1.300 Seismic, E 1.000 Retain Pro Software © 2009 HBA Publications, Inc.Licensed to: Erin Riderwww.RetainPro.com All Rights ReservedFort Worth, TX 76409 Page: _____ Freese and Nichols, IncBuilt Wall-Contractor's Fix_ Title : Job #Dsgnr:Date: CPL03243MMTAUG 26,2010 : 4055 International Plaza Description.... Suite 200 Fort Worth, TX 76109 This Wall in File: T:\St\CPL03243\coppell retaining walls.rp5 Retain Pro 9 © 1989 - 2009 Ver: 9.09 8119 Cantilevered Retaining Wall Design Code: AASHTO LRFD Registration #: RP-1167205 RP9.09 Licensed to: Erin Rider Footing Dimensions & StrengthsFooting Design Results 2.50 Toe Width=ft Toe Heel Heel Width= 2.75 Factored Pressure= 0 0psf Total Footing Width= 5.25 Mu' : Upward= 0 0ft-# Mu' : Downward= 914 2,547ft-# Footing Thickness =in 18.00 Mu: Design= 914 2,547ft-# Key Width=in 12.00 ctual 1-Way Shear= 2.17 15.65psi A Key Depth=in 9.00 Allow 1-Way Shear= 75.00 75.00psi Key Distance from Toe= 2.50ft Toe Reinforcing=# 5 @ 18.00 in Heel Reinforcing=# 5 @ 18.00 in f'c= 2,500psiFy= 60,000psi Key Reinforcing=# 5 @ 19.25 in Footing Concrete Density= 150.00pcf Min. As % 0.0018= Other Acceptable Sizes & Spacings Cover @ Top= 2.00in @ Btm.= 3.00in Toe:Not req'd, Mu < S * Fr Heel:Not req'd, Mu < S * Fr Key:Not req'd, Mu < S * Fr Summary of Overturning & Resisting Forces & Moments .....OVERTURNING..........RESISTING..... ForceDistanceMomentDistanceMomentForce lbsftft-#lbsftft-# Item Heel Active Pressure= 1,871.7 1,299.4 2.75 5,147.2Soil Over Heel= 4.38 5,684.8 Surcharge over Heel= 990.0 4.13 4,083.8Sloped Soil Over Heel= Toe Active PressureSurcharge Over Heel= = 0.50 Surcharge Over Toe=djacent Footing Load= A djacent Footing Load= A xial Dead Load on Stem= A Added Lateral Load= 1,878.8 11.00 20,666.8 * Axial Live Load on Stem= Load @ Stem Above Soil=Soil Over Toe= Surcharge Over Toe= Stem Weight(s)= 1,012.5 3.00 3,037.5 Earth @ Stem Transitions= = 4,740.5= 29,897.8 TotalO.T.M. 1,181.3 2.63 3,100.8 Footing Weight= =Key Weight= 112.5 3.00 337.5 Resisting/Overturning Ratio 0.41 Vertical Loads used for Soil Pressure = 3,605.6lbs Vert. Component= = 3,605.6lbs 12,160.5 Total =R.M. * Axial live load NOT included in total displayed, or used for overturning resistance, but is included for soil pressure calculation. DESIGNER NOTES: Retain Pro Software © 2009 HBA Publications, Inc.Licensed to: Erin Riderwww.RetainPro.com All Rights ReservedFort Worth, TX 76409 12.in Conc w/ #5 @ 15.in o/c 1 3/4" 6'-9"6'-9" 2" 1'-6" 3" #5@18.in @ Toe 9" #5@18.in @ Heel Designer select all horiz. reinf. See Appendix A 2'-6"1'-0"1'-9" 2'-6"2'-9" 5'-3" 1879.psf 240.psf 4740.5# Pp= 1139.1# Page: _____ Freese and Nichols, IncBuilt Wall-Contractor's Fix_ Title : Job #Dsgnr:Date: CPL03243MMTAUG 26,2010 : 4055 International Plaza Description.... Suite 200 Fort Worth, TX 76109 This Wall in File: T:\St\CPL03243\coppell retaining walls.rp5 Retain Pro 9 © 1989 - 2009 Ver: 9.09 8119 Cantilevered Retaining Wall Design Code: AASHTO LRFD Registration #: RP-1167205 RP9.09 Licensed to: Erin Rider CriteriaSoil Data =Allow Soil Bearing=psf 2,500.0 Retained Height 6.75ft Equivalent Fluid Pressure Method Wall height above soil=ft 0.00 55.0 Heel Active Pressure=psf/ft Slope Behind Wall= 0.00: 1 Toe Active Pressure= 0.0psf/ft Height of Soil over Toein 24.00Passive Pressure=psf/ft 300.0 = Soil Density, Heel=pcf 110.00 0.0 Water height over heel=ft Soil Density, Toe 110.00pcf = Footing||Soil Friction= 0.460 Soil height to ignore for passive pressure= 0.00in Thumbnail Surcharge LoadsLateral Load Applied to Stem Adjacent Footing Load Surcharge Over HeelpsfAdjacent Footing Load= 0.0lbs = 240.0 Lateral Load= 0.0#/ft NOT Used To Resist Sliding & Overturning Footing Width= 0.00ft = 10.25ft ...Height to Top Surcharge Over Toepsf= 0.0 Eccentricity= 0.00in ...Height to Bottom= 9.25ft NOT Used for Sliding & Overturning Wall to Ftg CL Dist= 0.00ft The above lateral load has been increased 2.17 Footing TypeLine Load Axial Load Applied to Stem by a factor of Base Above/Below Soil = 0.0ft xial Dead Load 0.0lbs A = at Back of Wall Wind on Exposed Stempsf 0.0 = xial Live Load 0.0lbs A = Poisson's Ratio 0.300= xial Load Eccentricity 0.0in A = Stem Construction Top Stem Design Summary As < Min % Wall Stability RatiosDesign Height Above Ftg ft= 0.00 = Overturning 1.39Ratio < 1.5! Wall Material Above "Ht"=Concrete 1.61 OK Sliding= Thickness= 12.00 Rebar Size=# 5 Rebar Spacing=15.00 Total Bearing Load= 4,156lbs ...resultant ecc.= 21.06in Rebar Placed at=Edge Design Data Soil Pressure @ Toe= 3,183psf NG fb/FB + fa/Fa= No Good Soil Pressure @ Heel= 0psf OK Total Force @ Section= 3,486.4lbs 2,500 llowable=psf A Moment....Actual= 9,384.5ft-# Soil Pressure Exceeds Allowable! Moment.....Allowable= 11,142.5 CI Factored @ Toe= 4,138psf A Shear.....Actual= 28.5psi CI Factored @ Heel= 0psf A Shear.....Allowable= 90.0psi Footing Shear @ Toe= 18.2psi OK Wall Weight= 150.0 Footing Shear @ Heel = 15.6psi OK Rebar Depth 'd'= 10.19in llowable= 75.0psi A LAP SPLICE IF ABOVE= 12.00in (Vertical Component NOT Used) Sliding Calcs LAP SPLICE IF BELOW= in Lateral Sliding Force 2,861.7lbs = HOOK EMBED INTO FTG 8.81= in less 100% Passive Force= 2,709.4lbs - Masonry Data less 100% Friction Force= 1,911.6lbs - f'm=psi lbs OK dded Force Req'd= 0.0 A Fs=psi ....for 1.5 : 1 Stability= 0.0lbs OK Solid Grouting= = Modular Ratio 'n' Short Term Factor= Equiv. Solid Thick. = Load Factors Masonry Block Type=Medium Weight Building CodeAASHTO LRFD =SD Masonry Design MethodA Dead Load 1.300 Concrete Data Live Load 2.170 f'c= 3,600.0psi Earth, H 1.690 Fy= 60,000.0psi Wind, W 1.300 Seismic, E 1.000 Retain Pro Software © 2009 HBA Publications, Inc.Licensed to: Erin Riderwww.RetainPro.com All Rights ReservedFort Worth, TX 76409 Page: _____ Freese and Nichols, IncBuilt Wall-Contractor's Fix_ Title : Job #Dsgnr:Date: CPL03243MMTAUG 26,2010 : 4055 International Plaza Description.... Suite 200 Fort Worth, TX 76109 This Wall in File: T:\St\CPL03243\coppell retaining walls.rp5 Retain Pro 9 © 1989 - 2009 Ver: 9.09 8119 Cantilevered Retaining Wall Design Code: AASHTO LRFD Registration #: RP-1167205 RP9.09 Licensed to: Erin Rider Footing Dimensions & StrengthsFooting Design Results 2.50 Toe Width=ft Toe Heel Heel Width= 2.75 Factored Pressure= 4,138 0psf Total Footing Width= 5.25 Mu' : Upward= 8,804 0ft-# Mu' : Downward= 1,808 2,547ft-# Footing Thickness =in 18.00 Mu: Design= 6,996 2,547ft-# Key Width=in 12.00 ctual 1-Way Shear= 18.19 15.65psi A Key Depth=in 9.00 Allow 1-Way Shear= 75.00 75.00psi Key Distance from Toe= 2.50ft Toe Reinforcing=# 5 @ 12.00 in Heel Reinforcing=# 4 @ 18.00 in f'c= 2,500psiFy= 60,000psi Key Reinforcing=# 5 @ 19.25 in Footing Concrete Density= 150.00pcf Min. As % 0.0018= Other Acceptable Sizes & Spacings Cover @ Top= 2.00in @ Btm.= 3.00in Toe:#4@ 7.75 in, #5@ 12.00 in, #6@ 17.00 in, #7@ 23.00 in, #8@ 30.50 in, #9@ 38 Heel:Not req'd, Mu < S * Fr Key:Not req'd, Mu < S * Fr Summary of Overturning & Resisting Forces & Moments .....OVERTURNING..........RESISTING..... ForceDistanceMomentDistanceMomentForce lbsftft-#lbsftft-# Item Heel Active Pressure= 1,871.7 1,299.4 2.75 5,147.2Soil Over Heel= 4.38 5,684.8 Surcharge over Heel= 990.0 4.13 4,083.8Sloped Soil Over Heel= Toe Active PressureSurcharge Over Heel= = 1.17 Surcharge Over Toe=djacent Footing Load= A djacent Footing Load= A xial Dead Load on Stem= A Added Lateral Load= * Axial Live Load on Stem= Load @ Stem Above Soil=Soil Over Toe= 550.0 1.25 687.5 Surcharge Over Toe= Stem Weight(s)= 1,012.5 3.00 3,037.5 Earth @ Stem Transitions= = 2,861.7= 9,231.0 TotalO.T.M. 1,181.3 2.63 3,100.8 Footing Weight= =Key Weight= 112.5 3.00 337.5 Resisting/Overturning Ratio 1.39 Vertical Loads used for Soil Pressure = 4,155.6lbs Vert. Component= = 4,155.6 12,848.0lbs Total =R.M. * Axial live load NOT included in total displayed, or used for overturning resistance, but is included for soil pressure calculation. DESIGNER NOTES: Retain Pro Software © 2009 HBA Publications, Inc.Licensed to: Erin Riderwww.RetainPro.com All Rights ReservedFort Worth, TX 76409 12.in Conc w/ #5 @ 15.in o/c 1 3/4" 6'-9"6'-9" 2'-0" 2" 1'-6" 3" #5@12.in @ Toe 9" #4@18.in @ Heel Designer select all horiz. reinf. See Appendix A 2'-6"1'-0"1'-9" 2'-6"2'-9" 5'-3" 240.psf 2861.7# Pp= 2709.4# 3182.9psf