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1 Geosynthetics&Geosystems Pilarczyk Pres Final

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application of geosynthetics and geosystems in hydraulic/coastal engineering

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1 Geosynthetics&Geosystems Pilarczyk Pres Final

  1. 1. Developments in Design and Application of Geosynthetics and Geosystems in Hydraulic and Coastal Engineering Krystian W. Pilarczyk Former: Rijkswaterstaat, Road and Hydraulic Engineering Institute, Delft, the Netherlands HYDROpil Consultancy, Zoetermeer, the Netherlands [email_address]
  2. 2. Developments in Design and Application of Geosynthetics and Geosystems in Hydraulic and Coastal Engineering General Introduction Part I: Geosynthetics in Revetments Part II: Geosystems (geotextile systems)
  3. 3. Getting older I understand more and more how little I know (how little my knowledge is) Therefore I have to disappoint you I have more to say on What we do not know than What we do know Why What How Geosynthetics & Geosystems (see also CEM 2006, Rock Manual 2007)
  4. 4. Why geosynthetics/geosystems? Critical review of geosystems in hydraulic/coastal engineering <ul><li>Geosynthetics applications are associated mainly with ground engineering (soil mechanic engineers) </li></ul><ul><li>Geosynthetics have already transformed geotechnical engineering to the point that it is no longer possible to do geotechnical engineering without geosynthetics (Giroud, 1987 ) </li></ul><ul><li>Why not (or less) in hydraulic and coastal engineering ?! </li></ul>
  5. 5. Conventional Applications
  6. 6. Why geosynthetics/geosystems? Why not in hydraulic and coastal engineering ? <ul><li>The design of geosystems was in the past based more on rather vague experience than on generally valid (accepted) calculation methods. </li></ul><ul><li>Contrary to research on traditional materials and systems there was little systematic research on the design, stability and performance of geosystems </li></ul>
  7. 7. Why geosynthetics/geosystems? <ul><li>the modern design approach is characterized by making a choice from a number of suitable alternatives </li></ul><ul><li>the shortage of natural resources </li></ul><ul><li>sometimes necessity (filters under water) </li></ul><ul><li>(often) cheaper and/or easier execution </li></ul><ul><li>available in a wide range of properties </li></ul>Design process
  8. 8. Why geosynthetics/geosystems? Why not in hydraulic and coastal engineering ? <ul><li>Past and recent research in the Netherlands, USA, Germany, Japan on a number of geosystems has provided results which can be of use in for preparation of design guidelines and design </li></ul><ul><li>We should convince the design engineer that geotextile systems can be a good and usually cheaper alternative to the more traditional materials and systems </li></ul><ul><li>Therefore : “Geosynthetics and Geosystems in Hydraulic and Coastal Engineering” </li></ul>www.Balkema.nl ; published in 2000
  9. 9. <ul><li>Revetments </li></ul><ul><li>Fill-containing geosystems </li></ul><ul><li>Geocontainers </li></ul><ul><li>Geotextile forms for sand </li></ul><ul><li>Screens and curtains </li></ul><ul><li>Inflatable dams </li></ul><ul><li>In dams and dikes </li></ul><ul><li>Erosion control </li></ul>Overview of geosynthetics/ geosystems (design methodology) (geosynthetics: properties&specifications) reality
  10. 10. Critical Review of Geosystems in Hydraulic and Coastal Engineering <ul><li>Introduction </li></ul><ul><li>Overview of systems </li></ul><ul><li>Stability criteria </li></ul><ul><li>Performance </li></ul><ul><li>Conclusions and recommendations </li></ul>
  11. 11. Why design methodology? <ul><li>integrated design : geotextiles and geosystems are only a part (or a component) of the total structure/project and they should be treated and integrated in the total perspective of a given project </li></ul><ul><li>basic knowledge of total design (aspects and principles) and basic knowledge of geosynthetics properties/specifications </li></ul>
  12. 12. Systems & Materials examples First: solve the problem( functional design) Then: systems & materials (structural design)
  13. 13. In the design process one has to distinguish between functional design (solve the problem) and structural design . Functional design concerns the impacts and performance of the coastal alternative with respect to coastal protection, improvement of recreational conditions and conservation of natural living resources. Structural design concerns the resistance of the coastal structure/materials to the actions of waves and currents Initial considerations Environmental conditions Functional pre-design alternative Selection of preferred scheme Detailed design Design Starting Points
  14. 14. Wave attack and Interactions with structures and Breaker index L=gT 2 /2 π =1.56T 2 L local =T (gh)^0.5 h= local depth in front of structure
  15. 15. Manufacturing , Products and Specifications Wovens Non-wovens
  16. 16. Geosynthetics: types and properties Terrafix non-woven composite Wovens vs. Non-wovens
  17. 17. Geotextiles
  18. 18. Specifications Example of woven materials
  19. 19. Remarks on specifications: woven vs. non-woven Wovens: high strength available, small elongation, bad performance at puncturing Non-wovens:lower strength, high elongation, good performance at puncturing, Good soil protection (if thick, i.e., needle-punched) Elongation at break
  20. 20. Example of geotextile properties
  21. 21. Bed and bank protection /mattresses/ high pulling forces - high tensile strength needed (wovens)
  22. 22. Composite products for special applications Woven for strength Non-woven for filtering or surface protection (The type of interconnection is very important for performance) Also non-woven composites
  23. 23. Specifications and Certifications <ul><li>CEN (European Normalization) </li></ul><ul><li>ASTM </li></ul><ul><li>(American Society for Testing and Materials) </li></ul>Each manufacturer has to provide specifications according to international standards and certifications
  24. 24. Part I Geosynthetics in Revetments
  25. 25. Alternative revetment systems conventional ??? <ul><li>Block mattresses </li></ul><ul><li>Concrete geomattresses </li></ul><ul><li>Sand mattresses </li></ul><ul><li>Sand bags </li></ul><ul><li>Wave load: </li></ul><ul><ul><li>Cover layer stability </li></ul></ul><ul><ul><li>Geotechnical stability of subsoil </li></ul></ul><ul><li>Load by high flow currents </li></ul>Geotextiles in revetment structures How to avoid failure ?
  26. 26. WAVE ATTACK Uplift of block mat or mattresses <ul><li>Λ leakage length, characterises the structure </li></ul><ul><li>At certain wave load: </li></ul><ul><ul><li>small leakage length => low uplift pressure </li></ul></ul><ul><ul><li>(high k’ gives pressure relief) </li></ul></ul><ul><ul><li>large leakage length =>high uplift pressure </li></ul></ul>or blocks
  27. 27. Prototype or large-scale verification uplift internal erosion Evidence of failure
  28. 28. Stability criteria revetments : wave attack For first estimation/conceptual design) Breaker index F=2.25 riprap F= 3-3.5 basalt F=4-6 blocks b = 0.5 for rip rap b = ½ to 2/3 for blocks Block revetments Usually in diagram form: www.tawinfo.nl
  29. 29. Example of stability diagram More examples can be found in: Dikes and Revetments, 1998, ed.K.W. Pilarczyk http://books.google.nl/books?ct=title&q=Coastal+Protection+,+Pilarczyk&lr=&sa=N&start=40
  30. 30. Pilarczyk’s formula for first estimation α = slope angle F= Φ Ψ u =2.25 Ψ u Ψ u = upgrading factor in respect to riprap ( Ψ u=1 and F= Φ = 2.25) www.tawinfo.nl
  31. 31. Example of composition and construction (Basalton) Geotextile filter Cushion layer Clay or sand Basalton
  32. 32. Block mats Cabled system
  33. 33. Cabled mat Blocks connected to geotextile by pins
  34. 34. Importance of proper composition/ leakage length example or Combined resistance/permeability influence of geotextile Geosynthetic is only one of the components involved
  35. 35. <ul><li>Compressible pore water + Pressure fluctuations </li></ul><ul><li>Reduced grain contact in sand </li></ul><ul><li>Local sliding </li></ul>Local geotechnical (in-)stability slip circle
  36. 36. Design diagram of geotechnical stability <ul><li>Load: Waves (& gravity component along slope) </li></ul><ul><li>Strength: Weight (cover layer + filter layer) </li></ul>
  37. 37. Principles of Filters arrest grains
  38. 38. Blockage of particles and sieve curves for geometrically closed filters
  39. 39. Geotextiles; comparison with granular filters Possible effectiveness of geotextile in filter: sieve curves and situation
  40. 40. O 90 < (1 to 2) D 90, base Definitions apertures geotextile and migration of fine particles
  41. 41. A lot of different criteria
  42. 42. Filter criteria for woven geotextiles; Mlynarek, 1994
  43. 43. Filter criteria for non-woven geotextiles ( Mlynarek, 1994)
  44. 44. Filter concepts Hydraulic gradients due to waves NL: geometrically sandtight: O 90 < D 90
  45. 45. Design diagram for geotextile filters Delft Hydraulics calculation programs
  46. 46. Testing and reality (performance) tests in FilterBox Index tests
  47. 47. Geotextile on clay Following geometrically closed rules provides very closed geotextile susceptible to clogging. Clay (due to cohesion) has 3 times or more resistance to erosive forces. Proposed: calculate the opening of geotextile (al least) just as for sand. No official rules on that point are known (except NL).
  48. 48. Geomats and Geomattresses PROFIX-sand-sausages mat Concrete-filled geomattresses
  49. 49. Sand mat (a measure for unstable soils)
  50. 50. Erosion Control Geoweb 3dim Composite mat
  51. 52. <ul><li>foto van betonmatras </li></ul>Stability of Concrete mattresses under wave attack
  52. 53. before and after the storm Lack of design criteria
  53. 54. Damage hazards Theory of block revetments can be applied to concrete geomattresses
  54. 55. Combined permeability of a system Influence of leakage length
  55. 56. Durability of geomattresses components vs system Aging effect Mechanical damage of geotextile Execution and maintenance
  56. 57. ELASTOCOAST PILOTS IN THE NETHERLANDS STORM SEASON 2007/2008; ELASTOGRAN GMBH German product <ul><li>ELASTOCOAST consists of granular material fixed together with a </li></ul><ul><li>two-component polyurethane adhesive. In the Elastocoast system each individual rock is covered with a thin film of polyurethane. When cured this film bonds the rocks together only on their contact points, retaining a highly permeable, open structure. </li></ul><ul><li>NB. Similarity with open-stone asphalt (Fixtone) </li></ul>Some New Developments Taking sample in-site And cross view of structure Open Stone Asphalt
  57. 58. Gabions and stone mattresses Sack gabion Box gabion and gabion mattress Cylindrical gabion Sack gabions in closure works in S. Korea (Isbash) Plastic gabions (Sack) RM 5.2.2.7
  58. 59. Stability of Synthetic Gabions in Waves TUDelft: Master of Science Thesis on the Application of Synthetic Grids in Mattress Gabion Constructions and the Stability in Waves,June 2008 Mattress construction Pilarczyk’s stability relation improved friction long short short
  59. 60. Puncturing Falling stones
  60. 61. References online http:// books.google.nl/books?ct = title&q = Coastal+Protection +,+Pilarczyk&lr =& sa = N&start =0 http://www.library.tudelft.nl/ws/search/publications/theses/index.htm?to =2008&de= Hydraulic+Engineering&n =10&fr=2008&s=1&p=2 http://www.kennisbank-waterbouw.nl/ www.tawinfo.nl (select English, downloads) http:// www.wldelft.nl/rnd/publ/search.html (insert for Author: Breteler, Gent, or other name) http://www.vandermeerconsulting.nl/ http:// www.delftcluster.nl /
  61. 62. Conclusion <ul><li>Design methods are derived on basis of theory, giving reasonable results, for various alternative revetments (including geotextiles): </li></ul><ul><ul><li>Block mattresses (and interlocking blocks) </li></ul></ul><ul><ul><li>Concrete mattresses </li></ul></ul><ul><ul><li>Sand mattresses </li></ul></ul><ul><ul><li>Geosystems (sand bags, sand containers etc) </li></ul></ul><ul><ul><li>Gabions (and Reno-mattresses) </li></ul></ul><ul><li>Covering Wave load and Flow load </li></ul><ul><li>Necessary future research: </li></ul><ul><ul><li>experimental verification (new products) </li></ul></ul><ul><ul><li>refining of theory </li></ul></ul>
  62. 63. Discussion
  63. 64. Part II Geosystems Geotextile Systems
  64. 65. Innovation in Geosystems Project approach and Design process wide view
  65. 66. Geosynthetics and Geosystems in Coastal Applications
  66. 67. floaters Geosystems in coastal engineering: Principe of inclined curtain as a coastal protection measure anchores Double row of curtains
  67. 69. Artificial Seaweed (mats) as scour protection anchor
  68. 70. Protection submarine pipelines againt scouring Vertical geo-curtains (i.e. BEROSIN) Artificial Seaweed mats, eventually in combination with a block mat
  69. 71. Kliffende House Sylt Island
  70. 72. Geobags Repair Application Geobags Usually as temporary structures/measures Filled with sand or concrete
  71. 73. Geobags; execution aspects
  72. 74. Construction of groin or breakwater with geobags
  73. 75. Application of large geobags for underwater dam at Sylt
  74. 76. Filling procedure of Mexican system Mexican (large) geobags filled with lean concrete Large bags
  75. 77. Geotubes improvement of design techniques and execution stability innovation
  76. 78. Geotubes <ul><li>popular structure for shore protection </li></ul><ul><li>shape and strength acc. to Leshchinsky method </li></ul><ul><li>main problems: - durability (if exposed) - execution /positioning - stacking geotubes - filling with silty materials (consolidation) - seam strength </li></ul>
  77. 79. Application Geotubes
  78. 80. Design aspects of geotubes
  79. 81. Design Geotubes Calculation shape and strength Similar results using Leshchynski’s GeoCops Palmerton method
  80. 82. Remarks on specifications: woven vs. non-woven Seams and safety factors: Seams 50 to 70% of strength Safety factor ~2 Execution damage ~1.3 Chemical degradation ~ 1.5 Creep ~ 1.5 Usually total safety factor in calculation of required strength: FS ~ 4 to 5 Elongation at break For geotubes, if exposed, high strength needed 50 to 80
  81. 83. Similar results using Leshchynski’s GeoCops Calculation shape and strength
  82. 84. Distribution of pressure along geotube perimeter
  83. 85. Influence of fill-grade
  84. 86. Influence of submergence
  85. 87. Filling of Geotubes Pocket beach using geotubes
  86. 88. Example of project: AmWaj Island, Bahrein at low water
  87. 89. Functional design: wave transmission Delft Hydraulics, 2000 Geotubes core+riprap
  88. 90. Thailand Execution
  89. 94. Example of localized humps Proper anchoring and pumping technique
  90. 95. Typical section of geotextile tube application Surface protection: additional sheet ??? (usually does not work properly) Durability (still a problem) Usually, surface protection needed
  91. 96. Holes repaired with HDPE covers
  92. 97. http:// coastal.tamug.edu / am / StudentPowerpointPresentations /Laura_ Mullaney _ Geotubes _ on _ Galveston _ Island %20ppt/ Geotubes _ on _ Galveston _ Island.ppt http://coastal.tamug.edu/capturedwebsites/cepraconference/glo_coastal_presentations/samplejay/sld001.htm
  93. 98. Enclosure and Dewatering dredged materials Leshchinsky’s PC-model Nieuw applications and design techniques
  94. 99. Dike heightening with geotubes
  95. 100. Geocontainers - a new invention
  96. 101. Geocontainers; filling procedure
  97. 102. Application Geocontainers
  98. 104. INNOVATION Geocontainers Research & Development Dry tests (Nicolon) Forces and Deformations procedure
  99. 105. Terrafix Soft Rock (geocontainers) Test geocontainer non-woven
  100. 106. Installation and dumping geocontainer
  101. 107. Submerged reef, Gold Coast a view
  102. 108. Dumping loss material and Geocontainer
  103. 109. Dumping trajectory of geocontainer Accuracy of placement still a problem (especially for depth larger than 10m) high accuracy needed
  104. 110. Large-scale geocontainer tests Delta Flume
  105. 111. Large-scale tests Geotubes Delta Flume
  106. 112. Stability geotubes&geocontainers - first approximation For geotubes parallel to wave attack For geotubes perpendicular to wave attack; For L/D > 4
  107. 113. On crest On slope Stability large geobags on slopes (Oumeraci, 2002)
  108. 116. Geocontainers - PhD study by Juan Recio (2007)
  109. 117. Geocontainers Juan Recio 2007 PhD-study
  110. 118. Juan Recio Formulae & comparison Use thickness D= lc/4 ; min.D = lc/5 Current attack
  111. 119. Recio 2007 - final
  112. 120. Proposed geocontainers/geotubes reefs West India
  113. 121. Numerical simulations by Recio
  114. 122. Accuracy of placing ?! Possible application of geocontainers and geotubes (core of breakwater)
  115. 123. Geosystems Applications EuroGeo4 2008 A.Bezuijen et al.
  116. 124. Geocontainers: conclusions <ul><li>growing number of projects </li></ul><ul><li>design and execution (usually) based on past experience </li></ul><ul><li>(still) limited documented experience </li></ul><ul><li>new design criteria are in development </li></ul><ul><li>need for verification </li></ul><ul><li>need for well-documented experience ( a.o. accuracy of placing, performance ) </li></ul>
  117. 125. A.A. Balkema, Rotterdam Remaining questions and closing remarks: - durability - execution - damage - quality control www.balkema.nl
  118. 126. Durability/long-term performance ??? to be or not to be 50 years 100 years 200 years We have to answer that ! international cooperation/joined forces ( IGS !)
  119. 127. Remember In general it can be said that geosystems as well as all engineering systems and materials have (some) advantages and disadvantages which should be recognized before a choice is made. There is not one ideal system or material. Each material and system has a certain application at certain loading conditions and specific functional requirements for the specific problem and/or structural solution.
  120. 128. Remember <ul><li>When applying geosystems the major design considerations/problems are related to the integrity of the units during release and impact (impact resistance, seam strength, burst, abrasion, durability etc.), the accuracy of placement on the bottom (especially at large depths), and the stability. </li></ul><ul><li>When applying this technology the manufacturer's specifications should be followed. The installation needs an experienced contractor or an experienced supervision. </li></ul>
  121. 129. Remember alternatives integrated approach <ul><li>Geosynthetic is only one of the components involved , and </li></ul><ul><li>Geosystem is only a part of the total structure </li></ul><ul><li>Design criteria needed, but </li></ul><ul><li>Experience and engineering judgement play an important role in design and construction </li></ul>
  122. 130. Verification of design (design rules) Engineers are continually required to demonstrate value for money. Verification of a design is expensive. However, taken as a percentage of the total costs, the cost is in fact often very small and can lead to considerable long-term savings in view of the uncertainties that exist in geosystem design. The client should therefore always be informed about the limitations of the design process and the need for verification in order to achieve the optimum design
  123. 131. Reliability of design rules ??!!!
  124. 132. Monitoring of projects Systematic (international) monitoring of realized projects (including failure cases) and evaluation of the prototype data may provide useful information for verification purposes and further improvement of prediction methods. It is also the role of the national and international organizations to identify this lack of information and to launch a multiclient studies for extended monitoring and testing programmes.
  125. 133. General Conclusions and Recommendations <ul><li>definitions and procedures </li></ul><ul><li>materials versus systems </li></ul><ul><li>index tests vs performance tests </li></ul><ul><li>research versus practice </li></ul><ul><li>international harmonization </li></ul><ul><li>international design guidelines </li></ul><ul><li>international cooperation </li></ul>
  126. 134. Why geosynthetics/geosystems? i n hydraulic/coastal engineering <ul><li>the field of geosynthetics is progressing very fast </li></ul><ul><li>more standard applications are related mainly to ground engineering (filtration, reinforcement) </li></ul><ul><li>there is a number of promissing systems suitable for hydraulic/coastal applications (geotubes, eocontainers, geocurtains, etc.) </li></ul><ul><li>some incidental (still limited) experience and design methods are available </li></ul><ul><li>a growing interest in innovative/low-cost methods </li></ul>
  127. 135. Closing remarks <ul><li>A number of concepts still need further elaboration to achieve the level of design quality comparable with more conventional solutions and systems. </li></ul><ul><li>A number of uncertainties can be solved in the scope of graduation works and doctoral dissertations. However, for a number of systems more practical experience is also still needed under various hydraulic conditions. </li></ul><ul><li>The realization of this need is only possible if manufacturers, clients and researchers cooperate closely. </li></ul>critical review of geosystems in hydraulic and coastal engineering
  128. 136. Promotion of geosynthetics is still needed: - marketing - publicity - good cases - quality assurance/control - education & training students engineers (post-academial education)
  129. 137. www.balkema.nl Contents: 1. Introduction 2. General design methodology 3. Geosynthetics: properties and functions 4. Revetments and bed protections 5. Fill-containing geosystems 6. Geocontainers 7. Geotextile forms for sand structures 8. Screens and curtains 9. Inflatable dams 10. Geosystems in dams, dikes, banks, dunes 11. Erosion control systems 12. Remaining questions 936pages; More information:
  130. 138. Thank you Geosynthetics are benefit for our Society
  131. 139. References online http://books.google.nl/books?ct=title&q=Coastal+Protection+,+Pilarczyk http://www.library.tudelft.nl/ws/search/publications/theses/index.htm?to =2008&de= Hydraulic+Engineering&n =10&fr=2008&s=1&p=2 http://www.kennisbank-waterbouw.nl/ www.tawinfo.nl (select English, downloads) http:// www.wldelft.nl/rnd/publ/search.html (insert for Author: Breteler, Gent, or other name) http://www.vandermeerconsulting.nl/ http:// www.delftcluster.nl / www.balkema.nl (author: Pilarczyk)
  132. 140. The end And Discussion
  133. 141. Discussion
  134. 142. Remarks on non-woven geotubes We can calculate stresses for slurry in a non-woven geotextile; it should not make much a difference.  If the geotextile will deform significantly, we can do the calculations in parts.  Apply a little pressure, calculate the stress, use the geotextile modulus to find the elongation, add the elongation to the previous circumference L, use the modified L and run now for an increase pressure.  Repeat the process until reaching the desired pressure (or height of force T). 
  135. 143. However, deformations are not part of the calculations.  If you wish to include its effects, you can do the following: 1. Use a certain specified height (or specified strength or specified pressure).  Any specified value should be smaller than the final value. 2. Run the program and get the reinforcement force.  Calculate by hand the change in circumference for geotextile (dL=T/k where k is the stiffness of the geotextile). The new L is Ln=Lo+dL. 3. Input Ln as the circumference, increase the pressure (or strength of height) by another increment, and repeat the process. 4. When you get to the final increment of strength (or height of pressure) you have the final length of the circumference and final geometry.  The final length Lf minus the initial value Lo (un-deformed value) tells the amount of deformation that is likely to occur under certain working conditions for any deformable membrane.  From experience, the amount of deformation (even is 5%) will have little effects on the final shape or stress.  You can verify it by doing the process incrementally.
  136. 145. Geosynthetics in flood protection and dike construction
  137. 146. Traditional application of geotextiles as flood protection measures Piping boils
  138. 147. Innovative flood protection measures using geosynthetics Conventional??
  139. 148. Geosynthetics in dikes, banks and embankments
  140. 149. Inflatable Barrier Ramspol, NL Inflatable dams principle
  141. 150. Demontable Inflated Weir
  142. 151. Waterwalls water-filled bags/tubes
  143. 152. Geotextiles as filters in revetment structures Designing with geotextiles
  144. 153. Transitions = weak points

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