Fig.7  Where 1=Greenstick piles; 2=Pivoting adjustable shafts; 3=Panel; 4=Permeable or non-permeable membrane; 5=Reclaimed pulp. A=Starting water level; A-A1=Tidal range The Greenstick wall construction phases are as follows: 1 . Vertical screw piling of Greensticks as per stakeout axes 2 . FRP panels inserted into one row of Greensticks via the keyways to form a wall 3 . Waterproof geotextile membrane set into position 4 . Greenstick   joints   unlocked,      FRP   panel   wall   positioned   to   required   angle   &   made   firm   by   connecting   to   the supporting row of Greensticks to form a secure structure 5 . Dredged soil transferred over the Greenstick wall to fill the void Greenstick   piles   are   capable   of   holding   high   vertical   and   horizontal   loads.      The   slope   of   the   wall   reduces   the   active   earth pressure on the FRP panel, reducing the horizontal force and keeping the Greenstick in place.  The   Greensticks   and   the   FRP   panels   can   serve   as   a   permanent   structure   or   have   the   added   benefit   of   being   fully   removable and re-utilised elsewhere if required. The benefits of using Fibre Reinforced Plastic (FRP) panels FRP has a number of advantages compared with materials traditionally used in hydraulic engineering, for example: o Unlike concrete, low water absorption makes FRP resistant to freezing and thawing o FRP tensile strength is higher than that of steel o FRP can be manufactured with significantly higher abrasion resistance than that of concrete or steel o Usage of lightweight FRP is likely to reduce construction time and cost o FRP,   not   being   subject   to   chemical   or   electrochemical   corrosion,   is   suitable   for   marine   hydraulic   structures   and   is cheaper than concrete or steel o FRP has the thermal conductivity of wood, preventing ice from forming on the surface o FRP can be manufactured in any colour making it more aesthetically pleasing than other materials

GREENSTICK TECHNOLGY FOR DREDGING, PROTECTION FROM COASTAL EROSION & FLOOD DEFENCE Greenstick   technology   offers   a   brand   new   solution   for   a   wide   range   of   applications   that   require   mooring   in   water.      The Greenstick   is   a   screw   pile   with   a   patented   lockable   and   unlockable   joint ,   allowing   vertical   deployment   and   the   ability   to   set the required angle once the Greenstick is securely in place. The   Greenstick   can   be   manufactured   to   include   a   keyway   which   will   allow   FRP   panels   to   be   inserted   between   Greensticks   to build retaining walls of different shapes, size and purpose. (See Appendix 1, Fig.7))    The   Greenstick   can   provide   economic   and   environmental   solutions   in   the   following   areas,   although   there   are   many   other   uses not listed here: 1 . Creation of artificial territories for commercial or environmental use 2 . Protection from coastal erosion 3 . Creation of embankments and bank protection resistant to ice loads 4 . Effective and less environmentally damaging disposal of dredging soil 5 . Speeding up the current “pre-loading” method of dredged soil 6 . Efficient removal of sediment build up in non tidal waters   7 . Temporary or permanent cofferdams or breakwaters   8 . Protection of coastal land from intense winter storms 9 . Provision of clear shipping navigation channels 1 0 . Protection of earth dams and areas from flooding 1 . Creation of artificial territories for commercial or environmental use The   Greenstick   wall   technology   may   be   used   in   the   creation   of   artificial   territory   to   be   utilised   for   commercial   gain   or   for   using the   newly   formed   landmass   for   environmental   and   natural   purposes.      The   Greenstick   wall   system   is   less   invasive   than traditional   methods   of   land   reclamation   and,   due   to   the   lightweight   nature   of   the   simple   design,   likely   to   be   a   quicker   and   less expensive option. The   image   below   (Fig.1)   of   the   Nordsee   Luftbilder   project,   shows   an   example   of   an   existing   method   of   creating   artificial territory   where   the   gap   in   the   structure   allows   the   ebb   tide   to   escape   whilst   retaining   as   much   of   the   silt   as   possible   within.      A Greenstick   wall   could   replace   this   method   and   could   function   without   need   for   the   gap    ,   by   sloping   the   walls   at   an   appropriate angle,   the   ebb   tide   would   be   able   to   flow   freely   over   the   top   of   the   structure   whilst   more   of   the   silt   would   remain   inside, thereby speeding up the process, saving both time and cost. 

Fig.1 Nordsee Luftbilder project

A   particular   example   of   where   the   Greenstick   wall   technology   would   be   beneficial   is   in   the   Ukraine   where   an   alluvium   strip of   territory   between   the   coastline   and   existing   land   might   be   the   only   option   to   meet   the   legislation   laid   down   by   Seaport Law   [2]   which   requires   a   100   metre   water   protected   zone   between   the   coastline   and   newly   reclaimed   land   used   for   private commercial gain. 2.  Protection from coastal erosion   In   practice,   a   number   of   methods   are   used   for   passive   protection   of   the   coast   from   erosion.      The   advantage   of   using Greenstick   technology   lies   in   the   ease   and   speed   of   construction,   reliability   and   lower   costs.      Due   to   its   relatively   simple design,   it   is   possible   to   install   fibreglass   groins,   beams,   piers,   breakwaters,   freeboard,   flooded,    complete   and   incomplete profiles selected on the basis of wave loads at the construction site.  According   to   the   patent   [1],   Greenstick   piles   can   be   of   different   types   and   immersed   in   different   ways;   screw,   driven, suction   etc.      This   allows   the   Greenstick   pile   to   achieve   the   bearing   capacity   on   horizontal   loads   of   tens   of   tons,   enabling   the technology to be used not only in the applications described herein but also in port and offshore structures. The   image   below   (Fig.2)   shows   a   traditional   coastal   protection   project   in   Australia.      Utilisation   of   Greenstick   wall   technology would eliminate the need to transport tons of rock to site and reduce resource required in the construction process.

Fig.2 Australian coastal protection project

3.  Creation of  embankments and bank protection resistant to ice loads Since   the   embankment   slope   of   a   Greenstick   wall   is   made   from   FRP,   it   will   be   unaffected   by   icy   conditions.      In   the   case   of ice   drifts,   the   ice   fields   will   glide   over   the   surface   of   the   FRP   wall   without   destroying   it.      FRP   sheets   are   as   strong   and durable as steel; they are widely used in construction as walls for buildings, for roofing, bridges and road surfaces.   In   the   United   States   and   Europe,   FRP   panels   are   used   as   the   span   beams   for   railway   bridges,   quay   and   hydropower installations.      A   prime   example   of   the   use   of   FRP   panels   in   construction   is   in   Russia   where   a   fibreglass   seawall   was successfully built and used for a number of years along the stretch of coast between Adler and Tuapse. 4.  Effective and less environmentally damaging disposal of dredging soil It   is   well   known   that   cleaning   the   bottom   of   a   river   or   estuary   by   dredging   and dumping    the    soil    at    sea    is    environmentally    damaging,    primarily    because    the discharged    slurry    is    spread    by    waves    and    currents    for    tens    of    kilometres, destroying    essential    sea    bacteria    through    deprivation    of    oxygen.        It    is    also financially   costly,   given   that   the   soil   has   to   be   transported   from   the   site   to   the   sea by   land   vehicles   or   sea   vessels   both   of   which   incur   the   additional   costs   of   crew, fuel and time.  Since   the   volume   of   repairs   and   new   digging   in   ports   and   channels   is   increasingly annually,   so   the   costs,   both   environmentally   and   financially,   will   also   increase   if the   dumping   of   dredged   soil   in   the   sea   continues.      The   Greenstick   wall   technology can   be   used   in   the   development   of   a   more   cost   effective   and   environmentally sound    solution,    that    being    the    adoption    and    improvement    of    the    “pre-load” method   where   dredged   soil   can   be   utilised   on   site   and   retained   via   the   Greenstick wall.  (See point 5 and Fig.3 below) 5.  Speeding up the current “pre-loading” method of dredged soil   Greenstick wall technology can be used to accelerate reclaimed soil consolidation.  Fencing the walls of the reclamation area can be done by mounting the wall panels on the surface of the reclaimed soil.  (See Fig.3a).  Utilisation of the Greenstick walls is likely to be significantly cheaper and quicker than the existing method of creating soil dams by bulldozers.  (See Fig.3b)

Proposed Greenstick Technology

Existing pre-load method

Fig.3 b) the existing method of creating embankment dams using reclaimed soil where, 1 = earthen dam; 2 = reclaimed pulp; 3 = dam reclamation 2 nd  layer; 4 = draining layer; 5 = slurry pipeline

6.  Efficient removal of sediment build up in non tidal waters   Like   the   dredging   of   ports   and   approach   channels,   cleaning   silt   and   sediment   from   the   beds   of   reservoirs   and   other   non tidal waters presents an urgent environmental challenge.   Siltation   of   reservoir   beds   leads   to   a   number   of   environmental   problems;   an   increase   in   ground   water   levels   to   adjacent areas,    the    extinction    of    benthic    biogenesis,    overgrowth    of    coast    reeds    and    further    eutrophication    of    water    bodies resulting in the proliferation of algae which causes depletion of oxygen and the death of other organisms such as fish.  Clearing   the   beds   of   water   bodies   leads   to   the   formation   of   fresh   water   springs   and   revitalises   the   biosystem.      The Greenstick   wall   technology   can   be   used   to   create   an   artificial   territory   to   allow   ground   clearance   to   take   place   and   protect the area. 7.  Temporary or permanent cofferdams or breakwaters Building   on   the   coast   runs   the   risk   of   erosion   by   storms.      The   Greenstick   technology   allows   the   protection   of   the   site during   the   period   of   construction   from   damage   and   the   ablation   of   the   construction   materials   by   the   sea.         After construction   has   been   completed,   the   protective   Greenstick   wall   and   piles   can   either   be   dismantled   and   removed   or   left in   place   to   further   protect   areas   liable   to   flooding   or   from   storm   attack.      Earth   dams   can   be   strengthened   by   use   of   the Greenstick   wall   (any   passage   of   water   over   an   earth   dam   will   degrade   it   very   quickly   causing   a    water   fall   and   its   imminent self   destruction    )   ,   in   emergencies,   additional   height   can   be   added   to   provide   extra   protection   ,   weak   exposed   surfaces can quickly be protection if required , this again is a simple quick process. 8.  Protection of coastal land from intense winter storms Greenstick   walls   can   be   used   to   protect   coastal   land   or   resort   areas   from   the   damaging   effects   of   intense   winter   storms during   which   soil   and   beach   sand   is   taken   back   into   the   open   sea   and   landmass   is   subsequently   reduced.      The   installation of   a   Greenstick   wall   would   retain   coastal   or   reclaimed   land   by   acting   as   a   breakwater   to   reduce   the   wave   impact   and reduce coastal erosion.  (Fig.4 below)

Fig. 4 Construction of Greenstick walls for protection of coastal land from storms

9.  Provision of clear shipping navigation channels Sloping   Greenstick   walls   can   be   set   at   a   specific   angle    used   to   reduce   the   build-up   of   sediment   in   shipping   channels   due to currents and storms, thereby ensuring minimal disruption to valuable marine industries.  (See Fig.5)

Fig. 5  Greenstick navigation channel protection from sediment

10.  Protection of earth dams and areas from flooding The   Greenstick   walls   are   able   to   provide   protection   from   floods   to   earth   dams   and,   significantly,   an   unobtrusive, straight   forward   solution   to   areas   liable   to   flood,   which   is   a   global   problem.      Greenstick   walls   can   be   installed   either permanently or temporarily, thereby saving repair costs.  For   general   flood   protection,   the   Greenstick   walls   can   be   mounted   along   riverbanks   or   shorelines.      During   periods   of flood, the walls can be raised and lowered once the threat of flood has diminished.  (See Fig.6 below)

Fig. 6 Protection against flood wall Greenstick

SUMMARY The   Greenstick   solutions   outlined   above   provide   a   selection   of   potential   applications   for   this   brand   new   and   much required   technology.      As   countries   worldwide   continue   to   put   in   place   more   stringent   rules   and   laws   governing   heavy engineering and its’ effect on the global environment, new, less invasive technology will become increasingly necessary.   The   Greenstick   pile   alone   provides   many   solutions   for   those   industries   requiring   a   mooring   device   but,   with   the inclusion   of   the   FRP   Greenstick   wall,   can   replace   much   of   the   environmentally   detrimental   methods   that   are   presently the only ones available.   RESEARCH WORK Research   work   and   the   testing   of   Greenstick   piles   has   been   carried   out   by   The   University   of   Hull   in   the   UK   and   by   The Norwegian Register of Shipping Veritas. REFERENCES 1 . Patent GB 2500322 A 2013 – David West & Gennady Meltsov 2 . The Law of Ukraine on sea ports – June 2013 3 . Recommendations   for   the   design   of   artificial   territories   formed   by   refilled   soft   soils   of   marine   dredging   -   AV Skhola,   AS   Marchenko,   AK   Posuhovsky,   GI   Meltsov,   TI   Rabochaya.   MAGVT,      Odessa   State   Academy   of   Civil Engineering and Architecture Odessa1996 APPENDIX 1 - GREENSTICK TECHNOLOGY USING FRP PANELS The   image   below   (Fig.7)   demonstrates   how   Greenstick   technology   can   be   used   with   FRP   panels   to   create   a   retaining wall, in this case to create an artificial territory: