161 Sandy Dikes

August 20, 2006 Dear Editor in Chief, A scholar commented about the dikes made mostly of sand because the natural surrounding of the land is sandy. And the dikes are frequently exposed to leaks caused by flooding. The destructions cause repetitions of expensive repairs that are sometimes magnets to corruption; and asked: “Could the sand dike that is ‘repair-prone’ be checked; or not to be always being repaired?” The A.I. answered: “The dike would most likely be destroyed by the water and be a magnet for never ending repair and magnet for corruption if nothing would be done different from its previous failed ways…! Perhaps, just a ½” leak in the dike could destroy a million worth of dollars dike because it is built from sand or it is not built of boulders with cement and sand that bind them together perhaps as the Hollanders of ancient times did when building strong dikes. Perhaps there are three or more methods to stop leaks and liquefaction or erosion from different kind of materials such as: type: A- sandy, B- most are soil, C-clayey, D-with combination of sand, soil and grovel, E- most are grovel with sand and soil, F-most are boulders with some grovels and soil and sand. 1st method is to build expensive dikes out of the materials just on its near surrounding especially from those excavation to let the canal or river bed become deeper, 2nd method is to build expensive dikes from exported engineered materials, 3rd method -1st method or 2nd method is shielded with expensive outer protection for erosion made of concrete slab or any other type of exterior protection. And perhaps there are other ways which are not the traditional ones and need to be tried or experimented…! Example: Why experiment other cheap and practical method. Perhaps the principle of using the opponent’s strength to defeat the opponent- or ‘Tai chi’ self defense or ‘kung fu’ tactic. If the sand keep on letting the river bed be full of sands and the water over flow and the repetition of excavating the river bed is just waste of money then why create others ways. Example: using detachable fences made from plastics or concrete plywood with composite materials to be stronger as sidings or walls to direct the flow of water with sands or silt or lahars (volcanic sandy materials) and when the enclosure or two sidings are full of silts that it looks like a very long dike why repeat the procedure a little parallel distance example 100m apart from the previous enclosure. And if the sand or silt or lahars are accumulated to from like another dike why let the flow water with silt or sand or lahars passes thru between those two dikes created by placing sidings. Then repeat the cycles either on top or on the other two sides. This simple common sense could save lot of money than never ending fighting-which method is correct or whose group is superior because of credit- like being- ‘lizards’ or ‘crocodiles’ or ‘snakes’ because of twisted words in the brain cause by lack of other essential words blocked or hidden by other deceptive words or precepts of men. Creativities were destroyed because too much focus of this and this and this alone. Why risk, try, do and if it fails, try again and ask help or ask other opinions. A scholar asked: Could you explain ‘using detachable fences made from plastics or concrete plywood with composite materials to be stronger as sidings or walls to direct the flow of water with sands or silt or lahars (volcanic sandy materials)? The S.I. answered: “making composite materials is an expertise by engineers but just to explain here an example is an attempt to show that common man should not be afraid to experiment something to make available material in the surroundings or in the market be stronger by just adding or reinforcing something. A 3/16” concrete plywood could be available in the market and it is breakable or brittle; but it could be made to be stronger by sandwiching mesh wire or mesh strong plastic fiber and paste with epoxy or strong paste. And the out come of pasting two brittle materials or sandwiched with flexible and strong plastic could let brittle materials become stronger called a composite or built up materials. The composite materials could be used as sidings or walls. Walls could be assembled and disassembled or could be transferred. Braces and stiffeners and beams and posts could also be made to be transferable. Perhaps those foundations of post would really be permanent. A scholar asked: “Could low portion of towns or cities be protected from sudden flooding caused by heavy rains or over flowing river?” The A.I. answered: “Perhaps, yes, any extreme made by nature that other people could overcome could also be overcome by others if there is political will or people’s will to do something about the extreme or chaos. The specifics and ideas perhaps are just around…or just on the click of the mouse! Example: The layout of the dikes desired by the people or the mayor, as long as the dike encloses the town, and elevation of the dikes could be done by traditional methods thru

surveying taught in the class or taught to engineering student or thru practical ways either by the use of Global Positioning Satellite, ordinary leveling hose, or dumpy level survey instrument. On the other hand, just ask the resident to trace the highest recorded flood and design a dike a little higher say 2 feet from the record. Always remember that water could move, compress, erode, the sand or soil. Moreover, just a leak could become, little by little and eventually big to destroy expensive structure such as the big Dike. To prevent leakages of water to happen: Anything that water could not penetrate such as plastic cellophane that could last long could be used as insulation or prevention to water leakages; and sandwich them with pile of sands with binders-a chemical agent which causes sand to stick to each other like ordinary water and cement, iron rust, lime stone, etc. or sandwiched with pile of soil and covered by grass and plants-would form a wall or dike against water invasion or flooding. The durable insulation should be 1-2 meter or more below the natural or original ground, and it should also reach the design height. If the excavated ground example 0.2-0.3 width x 1-2m or more depth x not yet undetermined length is still sandy, dig deeper until it reaches a sticky or clayey soil or firm rock. The leak proof insulation could be made from plastic such as recycled plastic sewed together and treated with chemicals or water base asphalt to last longer. A series of 3/16 concrete plywood with 0.3 meter lapping embedded below to reach clayey soil and above to reach to desire height where maximum level was traced I think would serve the purpose also but expensive. To install pre fabricated concrete wall reinforced with steel and strong plastics are good options too for lasting and more permanent one and expensive too. To prevent the water to enter thru embedded or existing drainage canal, any strong material that could serve as check valve-which only allow going out water to go out and prevent out side water to enter in - would do a lot to prevent flooding. A marine plywood ½” thick painted with 3 coatings of enamel or epoxy or water proof asphalt all over as improvised check valve with a diameter of 0.6m for 0.6 concrete culvert pipes would serve the purpose. The check valve- should function like an ordinary check valve made of bronze bought from the hardware. The check valve should have plate with a smaller clearance than the swinging cover; perhaps 0.01m clearance. Therefore, for 0.6m culverts, the hole should be 0.6m diameters and the swinging cover should be 0.62m. A fish string made of strong plastic 1/8” diameter could be manipulated to form as two hinges so that the cover would stay input and could swing or open or close. The swinging should be vertical and the hinges on top, and the cover or gate should close if outside water would try to enter. And the water from the inside or domestic waste and storm rain catch in the town could open the cover or could swing as gate and the water could pass thru if the pressure is higher than from the outside. The plate made also of ½” thick marine plywood and with 3 coatings of enamel paint or epoxy or even water proof paint like asphalt should be installed on existing 0.6m culvert too by using only fish string tie on the reinforcement if it has. If none, drill holes using concrete drill and tie there. In addition, the plate could be cemented to look presentable and durable. For smaller outlets, smaller improvised check valve too should be used. For bigger outlets, bigger improvised check valve too should be use. All embedded existing outlets should have check valves. Or check valves could be modern; or using the latest available technology that it could sense when to close and when to open automatically. It could produce another economic stimulus or cash to flow; and enhanced creativity. If the check valve is not functioning well, it should be closed so that water would not enter thru it and the pump would seem to be useless; keep on pumping but the water is not being drained. Improvised pump could be used. They could also use their ordinary rice field pumps. They may fabricate using junk materials or salvage materials. Example: one could assemble a propeller made of metal or stainless with two blades & with 3” width and incline at 30 degrees and has a 15-1/2” diameter. Then enclose the propeller into a cylinder made from ¼” thick metal sheet or ½” thick plastic pipe with an inner diameter of 16” and a height equal to the distance from 30” above the wall and down the bottom of the catch basin with strainer attached to a 1 ¾” diameter round metal shafting. The shafting is designed not to vibrate much by having two supports at top and bottom and with bearings and with less obstruction to passing of water. And improvising transmission salvaged from old truck that changes the vertical rotation to a horizontal rotation when driven by a 65-horse power second hand example “Izuso” diesel engine. I think, this improvised submersible and vertical pump could lift 2 to 4m of water from catchments and could drain a 10 hectare of land of 0.4m depth of water for 2 hours. Then with this

sample, one could compute how many pumps would be needed to pump out all the water on the enclosed town if flooded with .4m depth. Or used pumps from the market, it could generate employment and let cash to flow and stimulate the economy. I think elevated canals will not be much needed. Just install the pumps adjacent to outlets and next at an existing drainage system and the water could just be thrown outside the wall. However, if the storm rain and the domestic water waste would just be 6” or 0.2m deep I think lesser pumps will do the job. For water entering thru roads, people could place there temporary ramp high enough and adjacent to the dike so that water could not enter. On the other hand, they might as well elevate the portion of the road where the wall or dike is adjacent. Central government should provide options or alternative solution, for emergency solution on cases like those flash flood and flood caused by overflowing of rivers and canals; so that diseases and damages to properties could be avoided. They should educate people that they should not depend too much on the central government as what former president JFK said. “Ask not what your country can do for you; ask what you can do for your country…” And bad habits caused by deceptions or those bad habits such as waiting and waiting or doing many things but accomplishing nothing could be minimized because of many words and many suggestions or many creativities or ideas that could result to concrete actions.” From someone