Planning, Design and Estimation of a Check Dam B.H. Ramathilagam 1, S. Murugesan 2, M. Manikandan 3, A. Arumugaraja 4, Assistant professor 1 2, 3, 4

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1 ISSN XXXX XXXX 2017 IJESC Research Article Volume 7 Issue No.4 Planning, Design and Estimation of a Check Dam B.H. Ramathilagam 1, S. Murugesan 2, M. Manikandan 3, A. Arumugaraja 4, Assistant professor 1 2, 3, 4, U. G. student Department of Civil Sethu institute of technology, Virudhunagar, India Abstract To overcome these issues on a global scale, water erosion is the most severe type of soil erosion. It occurs mostly in the form of running water. This study was to develop information from dam which check dam can be adopted for the purpose of ground water recharge. Dams are constructions built across a river or a stream and used to interrupt and store water for special purpose. Check dams are comparatively smaller and more temporary to other types of dams for the purpose of ground water recharge. The Study consisted of a site selection phase, a surveying phase, an planning phase, an design phase and estimation analysis..this Particular scheme lies in highly favourable zone for recharge as classified in the zonation map for Ground water recharge. By implementing this scheme, with in the zone of influence of about 1 km radius from the check dam site will be benefitted by way of percolation. Increase the Ground water level and increase the revenue through the ayacut. Totally Ha Ayacut is benefitted through Seventy Eight No s of wells. Moreover, all the wells (both domestic and agricultural wells) within the zone of influence will be recharged. The length of the check dam is 106m. The design and Estimation of the structure is done using the software Ms-Excel. The total estimation amount of the project is Rs Lakhs. Keywords : Ground Water-Recharge, Water Erosion Control, Check Dams, Flow Velocity. I. INTRO DUCTION A dam is a barrier that impounds water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect water or for storage of water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or leaves are used to manage or prevent water flow in to specific land regions. There are several types of check dams; each type of dam is constructed with different conditions. In general, some essential considerations of check dams need to be considered. First, the site of each check dam must be carefully inspected to assess dam settling. The slope of waterway should be no more than 50% and the depth to bedrock should be over 2 feet (Department of Environmental Quality, 2005). Second, check dams materials will vary depending on conditions and locations. Logs and rock are usually utilized in permanent or semi-permanent check dams for their stability, and sandbag is for short term purpose (Mississippi Department of Environmental Quality, 2011) This type of dam project can be widely utilized in small open channels and drainage ways, including temporary and permanent swales. Check dams flattens the gradient of channels and blocks streams from fluently flowing. As a consequence, not only the velocity of flow is mitigated, but also the path can be distributed toward vegetation. On another hand, check dams also trap sediments from streams which helps to reduce water erosion. II. S ITE S URVEYING Before starting surveying work to select the area where the check dam is constructed and some procedures should be consider for selecting a site the water demand and ground water is necessity for cultivate crops and increase revenue and standard of living afterwards opinion from public and grievance should be noted. leveling should be done in the proposed site with the use of surveying instrument like autolevel, tripod, tape, plump bob, thread. Surveying work of leveling is carried out from upstream to downstream of the river up to 50 M from the site then reduced level of each points should be calculated from height of collimation method. Site should be cleared from vegetable, leaves, un bushy level after foundation should be erected at where the soil is week depth up to 3m to 5 m. Figure 1 I. Plan of check dam The planning of check dam done should be in two views A) Half plan at top & half plan at foundation. b) cross -section of check dam A. Half plan at top & half plan at foundation Half plan from top view and half plan at foundation are shown in fig 2. From top view plan shows apron & of both U/S International Journal of Engineering Science and Computing, April

2 side and D/S side. from left to right half top plan shows figure 2. U/S Return wall then us bed level to crest and stilling basin is 6.40m wide afterwards cement concrete blocks in right side portion ends is apron in D/S bed level and 8.00m wide. total discharge through scour vents and over weir = cusecs Design discharge for the anicut = cusecs D. Stability calculation The stability of body wall of the anicut was checked for the following conditions: 1 Reservoir empty without eq 2. Reservoir at MWL,with tail water with uplift 3.Reservoir at FRL, no tail water with uplift 4.Upstream side fully silted up to crest, No silt/water at D/s side Figure:2 Half plan at top & half plan at foundation B. Cross-section of check dam Cross-section of check dam shows abutments, d/s wing at start,u/s wing & return, d/s wing at end, d/s wing at basin. cement concrete 1:3:6 using 40mm aggregate m15 graded aggregate with surface reinforcement details are shown in figure 3 1. Maximum stress= SV/b*(1+6e/b) = T/m 2 Minimum stress = SV/b*(1+6e/b) = T/m 2 2. Maximum stress= SV/b*(1+6e/b )=3.5442T/m 2 3. Maximum stress= SV/b*(1+6e/b) =3.5442T/m 2 4.Maximum stress= SV/b*(1+6e/b) =3.5442T/m 2 E. Surface flow Regime width Looseness factor = 4.83 sqrt ( ) =107.5m = Existing overall length /Regime width = M Figure 3 II. CROSS-SECTION DES IGN A. Design the check dam structure The check dam structure design in limit state method. Design should be followed by the rules of indian standard IS B. Rear water calculation To find out the discharge in the rear water calculation by applying manning s formula (i) area (A)= m 2 (ii) wetted perimeter (p) = m (iii)discharge=17497 cusecs. C. Front maximum water level The front maximum water level determines discharge the amount of water from anicut and back water length calculation : P/ H O 0.65 < 1.33 (velocity of approach should be taken) total discharge over the weir = m 3 /sec % of discharging passing = % Scour depth = 3.6 M Stilling basin level = m Total horizontal floor length: Length of u/s floor = 3.00m Width of the body wall = 2.50m D/s floor length = 6.80m Total floor length required =12.30 m providing stilling basin length = 6.40m Hence total floor length = 12.30m F. Downstream protection work Length of downstream protection block = 1.5 D =5.7 m Hence provide 4 rows of CC block of size 1.5x1.5x0.9 m tk of pitching (Is ) = 850mm International Journal of Engineering Science and Computing, April

3 slope of =2.00:1 Length of launching =8.560 m qty of stone reqd for tk = 0.85x 8.56 = m 3 Inner tk reqd = 7.276/8 = m Quantity of pitching provided = 10.4 m 3 Quantity of pitching required = m 3 G. Ups tream wing wall &returns earth pressure: Vertical component = KN Horizontal component = KN Maximum stress = P/A(1+6e/b) = KN/m 2 Minimum stress =P/A (1-6e/b) =5.145 KN/m 2 J. Design of downstream wingwall at end portion Earth pressure: Vertical component = KN/m 2 Horizontal component = KN/m 2 Maximum stress = P/A(1+6e/b) = KN/m 2 Minimum stress =P/A (1-6e/b) =3.728 KN/m 2 H. Design of downstream wing wall at start earth pressure: Vertical component = KN/M 2 Horizontal component = KN/M 2 Maximum.stress = P/A(1+6e/b) = KN/m 2 Minimum stress =P/A (1-6e/b) =73.277KN/m 2 K. Design of downstream wingwall at return portion earth pressure: Vertical component t= KN/M Horizontal co mponent= KN/ m2 Maximum stress = P/A(1+6e/b) = KN/m 2 Minimum stress =P/A (1-6e/b) =2.468 KN/m 2 I. Design of downstream wingwall at basin portion Earth pressure: Vertical component = KN/m 2 Horizontal component t= KN/m 2 Maximum.stress = P/A(1+6e/b) = KN/m 2 Minimum stress =P/A (1-6e/b) =7.309 KN/m 2 III.ES TIMATION The estimation of the total approximate cost of the project is calculated by the detailed estimated method are as in the below tabulation. International Journal of Engineering Science and Computing, April

4 SI.NO Qty Description of work Rate Per Amount 1 L.S Clearing the site L.S m 3 Earth work excavation for m foundation m 3 Earth work excavation in all m soils except medium rock m 3 Extra for every additional 6.90 m lead of 10m m 3 Extra for every additional lift of 1m 5.50 m C.C 1:4:8 using 40 mm Hard broken stone jelly A) 100 m 3 Up to 1.50 m depth below m C.C 1:3:6 using 40 mm hard broken stone jelly a) 1580 m 3 Upto 1.50 m 4.50 m depth below m Cement concrete 1:2:4 using 20mm metal a) 266 m 3 Up to 1.5 m depth below m b) 266 m 3 From 1.5 m depth -4.5 m below m Cement concrete 1:2:4 (Graded mix ) 60% of 40mm & 40% of 20mm a) 1580 m 3 Upto 1.5 m depth below m b) 266 m 3 Upto 1.00m height above m c) 49 m 3 From 1.00m height -4..5m m height above m 3 Cement concrete 1:1, 5:3 using 20 mm metal with minimum Reinforcement m m 3 Supplying and erecting centering for soffits steel M sheets of size 90 x60 cm and 10 BG stiffened Qtl Steel fabricating Qtl m 3 Forming sand filter of m course sand and fine sand m 3 Graded filter using broken m stone 10 to 80mm m 3 Gravel filling for protection m blocks m 3 Rough stone dry packing for m revetment m 3 Jeddy stone dry packing for m launching apron 18 L.S Provision for expansion joints on every 20m interval L.S L.S L.S Provision for bailing out of L.S L.S water fixing hydrology board, gaugeplates.marking stones etc. 20 L.S Provision for bank connection L.S L.S Total IV. CO NCLUSION From this study, by observing the results the following conclusions were made the purpose of the project is increase the Ground Water recharge through the increase a yield of Crops. The site of check dam is surveyed in the area of Kadamalaikundu village of Andipatti thaluk in Theni District. In this study consist of Surveying, Planning, Designing and Estimation. The Surveying work carried with the instrument of Auto-Level. The designing and estimation work are done in Ms - excel software. All the Results of design and estimated are found to be safe The IS code of Design is followed International Journal of Engineering Science and Computing, April

5 This method of design is considered to be better than the other methods available for design particularly for check dams From the design result it has been concluded that this design can be adopted for any check dams. The estimated cost of the check dam is found to be Total Rs Lakhs. This amount implies the material cost, labour cost and all other miscellaneous charges. REFERENCE [1] Hangxi Fan The Function of check dams and the effect of Check Dams on Water Erosion department of resource analysis, saint Marry s university of Minnesota, winona, MN [2] IS criteria for structural design of barriages and weirs. International Journal of Engineering Science and Computing, April