HEROES CONSULTANTNo. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. INTRODUCTION Foreword In professional project practice it can be divided into five chapters like earthwork design, water reticulation design, drainage and culvert design, road design and sewerage. In this project we conducted drainage and culvert design. This chapter will explain how the drainage system is designed, the process involved and the consideration taken. In geomorphology, a drainage system is the pattern formed by the streams, rivers, and lakes in a particular watershed. They are governed by the topography of the land, whether a particular region is dominated by hard or soft rocks, and the gradient of the land. A drainage system in agriculture is an intervention to control water logging aiming at soil improvement for agricultural production. A drainage system for industrial and residential is a facility to dispose of liquid waste. An effective drainage system must be planned, analyzed and designed which is very essential to control the quantity, quality, timing, distribution of runoff resulting from storm events and also to control the erosion. Besides, the capacity of storm water that flows through the drainage structures must be analyzed to determine their ability to convey the developed discharge to avoid flooding. Therefore, the process of designing the drainage system should be considered to the parameter such as the depth of drain, area of developed, the material used for the structure and other factors that can affect the performance of designed drainage system. In designing the drainage system, the concepts that have being used are according to standard in MASMA. Many problems in Malaysia related to urban water management has using HEROES CONSULTANT No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. MASMA (Urban Stormwater Management Manual Malaysia) which has been introduced by the government through JPS (Jabatan Pengaliran Dan Saliran) since 2001. Generally, these manual act as a guideline to manage and plan good stormwater and drainage system especially in urban and develop area. OBJECTIVE There are several objectives that have been made to meet in designing the drainage system for this project: a. To provide complete calculation and design detail for an effective minor conveyance system for residential discharge and storm water. b. To determine appropriate size of drain for the proposed system that can cater a maximum flow rate for ARI of 5 years. c. To understanding the basic concept and procedure in design the size of drainage system that can accommodate to the peak flow capacity by using MASMA. d. To provide an effective drainage system that following the standard that is provided in MASMA. e. To provide for public and private property convenience and safety from flooding. yIt. Desasiswa Lembaran. 3005. (mm/hr) = catchment area (ha) It A Rainfall intensity. Tingkat Bawah. Pulau Pinang. I Overland flow time of concentration using equation below: Adopted time of concentration. 14300 Nibong Tebal. Universiti Sains Malaysia. DESIGN CRITERIA AND ASSUMPTIONS Hydrological Calculation of Catchment For estimating the catchment runoff in urban or built up area. The formula is as follows: Qy = C. tc = to + td . Qy = y year ARI peak flow (m3/s) C y = dimensionless runoff coefficient = y year ARI average rainfall intensity over time of concentration. A 360 Where.HEROES CONSULTANT No. reference were made to the Rational Method outlined in ³DID ± urban stormwater Management Manual For Malaysia´ which relate peak runoff to rainfall intensity through a proportional factor. tc. Runoff Coefficient. FD is the adjustment factor for storm duration. ( RIt ) R T = = = the average rainfall intensity (mm/hr) for ARI and duration t. should be used for all types of ground cover. 14300 Nibong Tebal. C Recommended runoff coefficient (C) values for rainfall intensities ( I ) of up to 200mm/hr have been obtained from Design Chart 14. a value of C = 0.(ln (t))² + d (ln (t))³ where. 3005.HEROES CONSULTANT No. average return interval (years) duration (minutes) a to d are fitting constant dependent on ARI The design rainfall depth pd for a short duration d (minutes) is given by. Tingkat Bawah.2 (DID-Urban Stormwater Manual for Malaysia) have been used in determining of design rainfall intensities Ln ( RIt ) = a + b. interpolation between the applicable C values I = 200mm/hr and I = 400m/hr has been used. For I values between 200 and 400mm/hr. (DID-Urban Stormwater manual for Malaysia) respectively. Universiti Sains Malaysia. obtained from the published design curve. Pulau Pinang. when t < 30minutes Pd = P30 ± FD (P60 ± P30) Where P30. Desasiswa Lembaran. Ln (t) + c. P60 are the 30-minute and 60-minute duration rainfall depths respectively.9.3 (urban area). Polynomial expressions in the form of equation 13. . For I > 400mm/hr. Desasiswa Lembaran. Pulau Pinang.HEROES CONSULTANT No.1 Minor System Major System Velocity The velocity of design should be in the range of 0. Q = (1/n) x AR2/3 S1/2 5 years 50 years . Drain capacity Open and swale drain have been sized by using Manning¶s formula equation. Tingkat Bawah. HYDRAULIC ANALYSIS Design storm Open drain has been designed to cater for flows up to and including the minor system design ARI as specified in Table 4. Universiti Sains Malaysia. the design of the drain is assumed fail. 3005. if the condition is not fulfilled.6 m/s < v < 4 m/s. 14300 Nibong Tebal. Universiti Sains Malaysia. Step to determine rainfall intensity . Tingkat Bawah. Pulau Pinang. 14300 Nibong Tebal. 3005.HEROES CONSULTANT No. Desasiswa Lembaran. 2 m 0. Pulau Pinang. Desasiswa Lembaran.003 Assume velocity in the drain.05 ha 0.028 ha Determine overland flow time of concentration overland sheet flow to basin L S to to = = = = 9. Tingkat Bawah.66 min Based on volume 4-chapter 13 of the urban storm management manual on design rainfall.79 min n = 0. HYDROLOGICAL CALCULATION OF CATCHMENT AND HYDRAULIC CALCULATIONS FOR DRAINAGE SYSTEM HYDROLOGICAL CALCULATION OF CATCHMENT Swale drain DRAIN 1 DESIGN OF DRAIN IN ACCORDANCE TO URBAN STORM MANAGEMENT MANUAL FOR MALAYSIA Total pervious area of site = Total impervious area of site = 0.HEROES CONSULTANT No. 3005. the polynomial approximation of the IDF curves is as followed: Ln(Rlt) = a + b ln(t) +c (ln(t)2) + d (ln(t)3) . Universiti Sains Malaysia.87 m 2 % 107nL1/3 / S1/2 4.87 min 1 m/s 47. tc = 5. 14300 Nibong Tebal. V = Ld td = = Adopted time of concentration. 3005.75 mm/hr mm/hr mm mm mm/hr mm/hr mm mm t t = = 30 60 Impervious area Duration 5 10 15 20 30 P24h West Coast (120mm) 1.0089 The design storm for the durations of time of concentration.661 0.1689 0.d fitting constants depending on ARI State Location Data period Perak Bagan Serai 1960 1983 ARI (Year) 2 5 10 20 50 100 Coefficient of the IDF polynomial constants a b c d 4.60) = P30 = P60 = 94.0099 5.0944 0.04 62.75 94. Desasiswa Lembaran.75 47.7867 0.1686 0. Tingkat Bawah.0329 -0.0078 5.02 62. Pervious area I(5yrs.2726 0. 14300 Nibong Tebal.1993 0. Pulau Pinang.0059 5.816 -0.02 62.HEROES CONSULTANT No.1857 0.72 0.75 47.0024 5.3538 -0.60) = P30 = P60 = I(5yrs. Tc .4357 -0.4919 -0.276 0.42 0 .04 62.30) = I(5yrs.2436 -0.13 0.1436 0.0149 4.3431 0.3299 0. Where: R lt = the average rainfall intensity (mm/hr) for ARI and duration t average return interval (years) R = t = duration (min) a .85 1. Universiti Sains Malaysia.30) = I(5yrs. 03 0.074 m 0.36 0.85 17.32 0.85 17.HEROES CONSULTANT No.P30) Impervious area mm Pervious area FD Pd = = = 1.00 120 1.3 Duration (min) 5 10 15 20 30 100 2.48 0. The design rainfall depth for short d is given by equation 13. Universiti Sains Malaysia.80 0.176 .035 0.00 East Coast All 1.0164 cumec C Q = = 0.07 m R=A/P R = 0.00 Pervious area C Q = = 0.3 : Pd = P30 . A Channel wetted perimeter.72 0.74 0.54 0. B = = = = 1 : 0.013 cumec Determination of drain capacity : T = B +2ZY T = 3.62 0. S manning roughness.54 m2 P = B + Y{(1 + Z12)1/2 + (1 + Z22)1/2} P = 3.9 0.62 0.42 0. Desasiswa Lembaran.18 side slope (H : V) channel slope. P Hydraulic radius.00 Impervious area 180 1.00 West Coast 150 1. Pulau Pinang.40 0. 14300 Nibong Tebal.FD(P60 .85 1.39 1.99 0.86 0.92 190.07 mm/hr Values of FD for equation 13.00 m A = Y(B + T)/2 A = 0. R = = = 0.54 m2 3.28 0.6 4 Channel area.92 FD Pd I(5yrs. n base width. 3005.08 1.62 0. tc) 190.002 0.07 mm mm/hr I(5yrs.47 0.13 0. Tingkat Bawah. tc) = = = 1. HEROES CONSULTANT No. Y Q = (1/n) x A x R2/3 x So1/2 = = .3 Q = 0. 14300 Nibong Tebal. Universiti Sains Malaysia.5 .0297 Calculation of Qpre (before construction) DESIGN OF DRAIN IN ACCORDANCE TO URBAN STORM MANAGEMENT MANUAL FOR MALAYSIA Total pervious area of site = 1 ha Adopted time of concentration.5 (km2) tc = data L S A = = = 0.401 cumec > m/s Qpeak OK! . 58. tc tc = Fc x L / A1/10 x S1/5 where tc L S A = = = = min length flow path to outlet (km) slope catchment area.02 1 ha km2 km Fc = Fc 5. Desasiswa Lembaran. Tingkat Bawah. Qpeak = 0. (ha) 92. Pulau Pinang. 3005. 3 0.2164 0.07 5. top width water depth.672 = min 58.5 (ha) .2164 Q V = Q/A V = = 0. 30) = I(5yrs.42 0 t = = 30 60 5 10 15 20 30 . 3005.3431 0.0089 The design storm for the durations of time of concentration.13 0.7867 0.85 1.72 0.0329 -0.1436 0. Based on volume 4-chapter 13 of the urban storm management manual on design rainfall. 14300 Nibong Tebal.276 0.0024 5. Desasiswa Lembaran.0099 5. t Pervious area I(5yrs.1686 0.3538 -0.4357 -0. Pulau Pinang. the polynomial approximation of the IDF curves is as followed: Ln(Rlt) = a + b ln(t) +c (ln(t)2) + d (ln(t)3) Where: lt = the average rainfall intensity (mm/hr) for ARI and duration t R = average return interval (years) t = duration (min) a .1689 0.661 0.0059 5.2726 0.1857 0.60) = P30 = P60 = Duration 107.d fitting constants depending on ARI R State Location Data period Perak Bagan Serai 1960 1983 ARI (Year) 2 5 10 20 50 100 Coefficient of the IDF polynomial constants a b c d 4. Tingkat Bawah.28 mm/hr 71.816 -0.2436 -0. Universiti Sains Malaysia.60 mm/hr 53.HEROES CONSULTANT No.1993 0.3299 0.0149 4.4919 -0.0944 0. Tc .0078 5.60 mm P24h West Coast (120mm) 1.64 mm 71. 016 0.000 Qtotal 0.027 0.010 0.42 0.85 1.013 0.027 0.018 0.022 0. Universiti Sains Malaysia. Tingkat Bawah.006 0.016 0.013 0.47 0.28 0.016 0.72 0.48 0.74 0. Desasiswa Lembaran.042 0.011 0. tc) = = = 1.80 0. The design rainfall depth for short d is given by equation 13.3 : Pd = P30 .HEROES CONSULTANT No.3 Duration (min) 5 10 15 20 30 Pervious area 100 2.62 0.010 0.016 0.05 mm mm/hr Values of FD for equation 13.016 0.008 0.P30) Pervious area FD Pd I(5yrs.010 0.000 0.000 0.00 East Coast All 1.99 0.011 0.03 0.85 20.000 0.00 C Qpre = = 0.08 1.13 0. 3005.00 180 1.86 0.016 0.022 0.42 216.016 0.022 Qimpervious 0. Pulau Pinang.54 0.030 0.62 0.384 cumec Calculation of result Drain 1 2 3 4 5 6 7 8 9 10 11 Qpervious 0.029 0.00 150 1.64 0. 14300 Nibong Tebal.00 West Coast 120 1.FD(P60 .010 0.005 0.40 0.022 Qpost = 0.36 0.233 .32 0.069 0.39 1. 3005. 14300 Nibong Tebal.5 m 2 % 107nL1/3 / S1/2 13. Universiti Sains Malaysia. Pulau Pinang.35 min 1 m/s 27 m 0.012 0.011 0.384 > Qpost OK Concrete drain DESIGN OF DRAIN IN ACCORDANCE TO URBAN STORM MANAGEMENT MANUAL FOR MALAYSIA Total impervious area of site = Determine overland flow time of concentration overland sheet flow to basin L S to to Assume velocity in the drain. the polynomial approximation of the IDF curves is as followed: Ln(Rlt) = a + b ln(t) +c (ln(t)2) + d (ln(t)3) Where: R lt R t = = = the average rainfall intensity (mm/hr) for ARI and duration t average return interval (years) duration (min) a .014 0.07 ha Based on volume 4-chapter 13 of the urban storm management manual on design rainfall.027 0.d fitting constants depending on ARI . V = Ld td Adopted time of concentration.016 0.233 = 0.014 0.000 0.011 0.023 0.000 0.45 min 13. 12 13 C1 C2 0. Tingkat Bawah.014 Qpost total 0.013 0.014 0.80 min n = 0. Desasiswa Lembaran.HEROES CONSULTANT No. tc = = = = = = = 2. 75 mm t t = = 30 60 Duration 5 10 15 20 30 P24h West Coast (120mm) 1. Pervious area I(5yrs. tc) = = = 1.9 mm mm/hr .1436 0.75 mm/hr 47. State Location Data period Perak Bagan Serai 1960 1983 ARI (Year) 2 5 10 20 50 100 Coefficient of the IDF polynomial constants a b c d 4.30) = I(5yrs. Tc .816 -0.1857 0.3538 -0.60) = P30 = P60 = Impervious area I(5yrs.02 mm 62. Tingkat Bawah.85 1.0099 5.30) = I(5yrs.3299 0.0329 -0.4919 -0.85 17.02 mm 62.92 77.13 0.1686 0.0078 5.0944 0.276 0.FD(P60 .661 0.2726 0. Desasiswa Lembaran.0059 5.7867 0.3 : Pd = P30 .75 mm/hr 47.P30) Impervious area FD Pd I(5yrs.60) = P30 = P60 = 94. 14300 Nibong Tebal. Universiti Sains Malaysia.1689 0.1993 0.04 mm/hr 62.0024 5.0149 4.75 mm 94.04 mm/hr 62.HEROES CONSULTANT No.42 0 The design rainfall depth for short d is given by equation 13.4357 -0. 3005.0089 The design storm for the durations of time of concentration.3431 0.2436 -0. Pulau Pinang.72 0. 014 cumec area of cross section. Desasiswa Lembaran.014 m3/s mm = = 120 1. 14300 Nibong Tebal.00 C Q Drainage design design discharge. A = Wetted perimeter.029 m3/s 0.075 > 0.00 East Coast All 1.47 0.002 0.48 0.86 0.54 0.00 0.62 0.85 1.6 m S n = = 0.36 0. V = Q/A V = = 0.9 0.00 180 1. 3005. Pulau Pinang. Tingkat Bawah.00 West Coast 150 1.42 0.08 1. Values of FD for equation 13.645 m/s < 4 m/s OK use size 300 mm x 300 mm .HEROES CONSULTANT No.72 0.3 Duration (min) 5 10 15 20 30 Impervious area 100 2.40 0.74 0. R = Capacity.03 0.13 0.39 1.80 0.28 0. P Hydraulic radius.045 m2 0.013 b= 300 0. Q = Velocity. Universiti Sains Malaysia.003 m3/s OK = = = 2y b/2 150 mm 0.62 0.32 0.99 0. Qpost = try U drain size Manning equation Q = AR2/3So1/2/n b y y by b +2y A/P = = = 0. Pulau Pinang.776 1.002 0.002 0.002 0.002 0.902 1.002 0. Tingkat Bawah.906 22 m 0.002 0.002 0.940 1.884 .742 1.906 m 1.862 1.906 1.822 1.fall Drain 1 Length = IL1 = = IL2 = = Drain 2 Length = IL3 = = 1. GL = Depth = Gradient = 1.HEROES CONSULTANT No.002 0.002 0.946 1.044 GL 47 m depth 2 m 2 0. Universiti Sains Malaysia. Example of calculation of invert level Ground level. Desasiswa Lembaran.002 invert level(m) 1.094 1.002 0. 14300 Nibong Tebal.002 0.862 m drain 1 2 3 4 5 6 7 8 9 10 11 12 13 slope 0.2 m IL = invert level fall = length x gradient IL2 = IL1 . 3005.972 1.804 1.946 1.002 0.826 1.2 m 1 : 500 3. Universiti Sains Malaysia. 3005. Tingkat Bawah.HEROES CONSULTANT No. Pulau Pinang. 14300 Nibong Tebal. CATCHMENT AREA . Desasiswa Lembaran. Universiti Sains Malaysia. Desasiswa Lembaran. 3005. .HEROES CONSULTANT No. Pulau Pinang. Tingkat Bawah. 14300 Nibong Tebal. Desasiswa Lembaran. Tingkat Bawah. 14300 Nibong Tebal. . Universiti Sains Malaysia.HEROES CONSULTANT No. Pulau Pinang. 3005. 3005. Universiti Sains Malaysia. 14300 Nibong Tebal. . Tingkat Bawah. Desasiswa Lembaran.HEROES CONSULTANT No. Pulau Pinang.