Combined Pile-Raft Foundations (CPRF) in Theory and Engineering Practice • Current Developments
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Symposium „Pile design and displacements“ The Hague, The Netherlands, 27th May 2016 Combined Pile-Raft Foundations (CPRF) in theory and engineering practice • Current developments Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics · TU Darmstadt • Past Chairman of the Technical Committee 212 “Deep Foundations“ (TC 212) of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE) • Board Member of the German Tunnel Association (STUVA) • Board Member of the German Geotechnical Society (DGGT) • Publicly Certified Expert and Independent Checking Engineering (ICE) Dipl.-Ing. Steffen Leppla • Research Associate at the Institute and Laboratory of Geotechnics · TU Darmstadt • Certified Independent Expert for Geotechnics of metro and tram systems Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Soil-structure interaction 1– 3 [MN/m²] What’s the problem? • Settlements • Differential settlements • Tilting Deep foundation systems planning design 1 [%] Frankfurt Clay construction Marl utilisation Sandstone Rocky Marl Gypsum Dubai Sandstone 2 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Subsoil in Frankfurt am Main, Germany Commerzbank Messeturm MAINTOWER ECB West East 2 Es(z) = 15 - 50 MN/m z 2 Es(z) > 250 MN/m 3 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Marriott-Hotel · Frankfurt am Main, Germany Construction time: 1973 - 1976 Height: 162 m Foundation: raft foundation max. settlements: 34 cm (!!) 4 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Marriott-Hotel · Frankfurt am Main, Germany Compensation of the settlements differences Stiff concrete cells (hotel area) Jacks Jacks Flexible steel construction (office area) Hinged connections 5 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Deutsche Bank · Frankfurt am Main, Germany Foundation: raft foundation Height: 155 m Settlements: min. 10 cm max. 22 cm Δ 12 cm 6 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Deutsche Bank · Frankfurt am Main, Germany Settlement isolines 22 7 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Deutsche Bank · Frankfurt am Main, Germany Compensation system in the joint between high-rise building and the adjacent building high-rise building adjacent building jacks 8 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Old Dresdner Bank Hochhaus · Frankfurt Pressure cushion h = 0.4 m Raft thickness: 3.0 – 4.0 m ~ 5.0 m ~ 7.0 m Retaining wall BohrpfahlwandBored pile wall Baugruben- Construction time: 1975 - 1978 sicherung max. settlements: 20 cm 9 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Soil-structure interaction Foundations Combined Pile-Raft Shallow foundations Pile foundations Foundation (CPRF) Skin friction pile Base pressure 10 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Combined Pile-Raft Foundation (CPRF) Total resistance of the CPRF: m Rtot,k s Rpile,k,j s Rraft,k s j1 Pile resistance: Rpile,k,j s Rb,k,j s Rs,k,j s Raft resistance: Rraft,k (s) s,x,ydx dy CPRF coefficient: m Rpile,, k j () s j1 CPRF Rtot, k () s 11 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Combined Pile-Raft Foundation (CPRF) Three foundation types Circular Raft Single Pile “1-Pile-Raft-Model” l = 30.0 m D = 1.5 m Dslab = 12.0 m d = 1.0 m 12 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Combined Pile-Raft Foundation (CPRF) Single pile foundation 5 MN Axial Force 8 MN s 13 MN Settlement s = settlement 13 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Combined Pile-Raft Foundation (CPRF) 14 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Combined Pile-Raft Foundation (CPRF) “1-Pile-Raft-Model” → Pile-Raft Interaction 4 MN Axial Force 6 MN s 12 MN Settlement s = settlement 15 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Basic studies on the pile-pile interaction Numerical Studies Combined Pile Raft Spread Foundation Pile Foundation Foundation Thickness of raft: d = 1.0 m Diameter of pile: D = 1.5 m Variations of pile center distance: e/D = 3.0 / 6.0 / 8.5 Variations of pile length: l/D = 10 / 20 / 30 16 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Basic studies on the Pile-Pile Interaction Configuration of the model with 25 piles (e/D = 3) d = 1.0 m D = 1.5 m e = 3 · D = 4.5 m l = 20 · D = 30 m 17 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Basic studies on the Pile-Pile Interaction Configuration of the model with 9 piles (e/D = 6) d = 1.0 m D = 1.5 m e = 6 · D = 9 m l = 20 · D = 30 m 18 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Basic studies on the Pile-Pile Interaction Load settlement behaviour e / D = 3.0 e / D = 6.0 19 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Basic studies on the Pile-Pile Interaction Load settlement behaviour Pile Foundation e = 3 · D CPRF e = 3 · D 20 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Basic studies on the Pile-Pile Interaction Load settlement behaviour Pile Foundation e = 6 · D CPRF e = 6 · D 21 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Proof and safety concept for CPRF = G ∙ R ≈ 2.00 22 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Proof and safety concept for CPRF SLS is more relevant! 23 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics ISSMGE · Technical Committee TC 212 Deep Foundations . Details: International www.issmge.org/tc212 CPRF-Guideline 24 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Modelling soil-structure interaction Numerical Analysis Constitutive law Geometry (non-linear and stress dependent) (3-dimensional model) 1 hydrostatic axis Fs Fc 2 3 25 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Bridge pier foundation types Option 1: Option 2: Option 3: Spread Foundation CPRF with 6 Piles Pile Foundation with 12 Piles 26 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Numerical model of foundation elements Option 1: Option 2: Option 3: Spread Foundation CPRF with 6 Piles Pile Foundation with 12 Piles 27 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Comparison of settlements Working Load: 30 [MN] Resistance [MN] 1.2 3.6 11.1 Settlement [cm] Pile Foundation Spread Foundation Combinded Pile-Raft Foundation 28 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Comparison of costs Costs of pile production Settlement (Assumption: 600 € per meter) Spread Foundation 11.1 cm - CPRF (6 Piles) 3.6 cm 55,000 € Pile Foundation 1.2 cm 180,000 € (12 Piles) 29 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Messeturm · Frankfurt am Main, Germany Settlements calculated for a shallow foundation: s > 40 cm Messeturm · Frankfurt am Main, z = 0 - 20 m → 75 - 80 % Germany Settlements: → Combined Pile-Raft Foundation (CPRF) 30 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Messeturm · Frankfurt am Main, Germany Construction time: 1988 - 1990 Quaternary sand and gravel Frankfurt Clay 31 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Messeturm · Frankfurt am Main, Germany Construction time: 1988 - 1990 Quaternary sand and gravel Frankfurt Clay 32 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Messeturm · Frankfurt am Main, Germany Average pile load: 11.3 MN 33 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Messeturm · Frankfurt am Main, Germany Effective building load: = 1.570 MN Ultimate pile load: 64 x 11.3 MN = 725 MN Load transfer by raft: = 845 MN Contact pressure: 250 kN/m2 αCPRF = 0.46 34 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics Messeturm · Frankfurt am Main, Germany Comparison of costs for the piles Accomplished: CPRF of 64 piles (laverage = 30 m) Costs of pile production: 64 piles of 30 m at 600 €/m 1.2 Mio. € Pile foundation: 316 piles (l = 30 m) Costs of pile production: 316 piles of 30 m at 600 €/m 5.7 Mio. € Savings in costs of pile production 4.5 Mio. € CO2 reduction: 2,500 t 35 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics European Central Bank · Frankfurt am Main, Germany 36 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics European Central Bank · Frankfurt am Main, Germany 37 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics European Central Bank · Frankfurt am Main, Germany 38 Prof. Dr.-Ing. Rolf Katzenbach • Director of the Institute and the Laboratory of Geotechnics European Central Bank · Frankfurt am Main, Germany Comparison of costs for the piles Accomplished: CPRF of 97 piles (laverage = 30 m) Costs of pile production: 97 piles of 30 m at 600 €/m 1.7 Mio.