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HEROES CONSULTANT  No. 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 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 stor m 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 t he 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. HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. DESIGN CRITERIA AND ASSUMPTIONS Hydrological Calculation of Catchment For estimating the catchment runoff in urban or built up area, 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. The formula is as follows: y Qy = C. It. A 360 3 Where; Qy = y year ARI peak flow (m /s) C = dimensionless runoff coefficient y = y year ARI average rainfall intensity over time of concentration, tc, (mm/hr) A = catchment area (ha) It  Rainfall intensity. I Overland flow time of concentration using equat ion below:       Adopted time of concentration, tc = to + td    HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. Polynomial expressions in the form of equat ion 13.2 (DID-Urban Stormwater Manual for  Malaysia) have been used in determining of design rainfall intensities Ln ( R It ) = a + b. Ln (t) + c.(ln (t))² + d (ln (t))³ where, ( R It ) = the average rainfall intensity (mm/hr) for ARI and duration t. R = average return interval (years) T = 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, when t < 30minutes Pd = P30 ± FD (P60 ± P30) Where P30, P60 are the 30-minute and 60-minute duration rainfall depths respectively, obtained from the published design curve. FD is the adjustment factor for storm duration.  Runoff Coefficient, C Recommended runoff coefficient (C) values for rainfall intensities ( I ) of up to 200mm/hr have been obtained from Design Chart 14.3 (urban area), (DID-Urban Stormwater manual for  Malaysia) respectively. For I > 400mm/hr, a value of C = 0.9, should be used for all types of  ground cover. For I values between 200 and 400mm/hr, interpolation between the applicable C values I = 200mm/hr and I = 400m/hr has been used. HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. 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 4.1  Minor System - 5 years Major System - 50 years Velocity The velocity of design should be in the range of 0.6 m/s < v < 4 m/s. if the condition is not fulfilled, the design of the drain is assumed fail.  Drain capacity Open and swale drain have been sized by using Manning¶s formula equation. Q = (1/n) x AR 2/3 S1/2 HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. Step to determine rainfall intensity HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. 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 = 0.05 ha Total impervious area of site = 0.028 ha Determine overland flow time of concentration overland sheet flow to basin L = 9.87 m S = 2 % to = to = 1/3 107nL Assume velocity in the drain, V = = 0.003 1/2 /S 4.87 min 1 m/s Ld = 47.2 m td = 0.79 min Adopted time of concentration, tc = n 5.66 min Based on volume 4-chapter 13 of the urban storm m anagement manual on design rainfall, the polynomial approximation of the IDF curves is as followed: R Ln( lt) = a + b ln(t) +c (ln(t)2) + d (ln(t)3) HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. Where: R lt = the average rainfall intensity (mm/hr) for ARI and duration t R = average return interval (years) t = duration (min) a - 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 4.1689 0.816 -0.2726 0.0149 4.7867 0.4919 -0.1993 0.0099 5.276 0.2436 -0.1436 0.0059 5.661 0.0329 -0.0944 0.0024 5.3431 0.3538 -0.1686 0.0078 5.3299 0.4357 -0.1857 0.0089 The design storm for the durations of time of concentr ation, Tc ; Pervious area Impervious area I(5yrs,30) = I(5yrs,60) = 94.04 62.75 mm/hr mm/hr P30 = 47.02 mm P60 = 62.75 mm I(5yrs,30) = I(5yrs,60) = 94.04 mm/hr 62.75 mm/hr P30 = 47.02 mm P60 = 62.75 mm Duration P24h West Coast (120mm) 5 10 15 20 30 1.85 1.13 0.72 0.42 0 t t = = 30 60 HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. The design rainfall depth for short d is given by equation 13.3 : Pd = P30 - FD(P60 - P30) Pervious area Impervious area FD = 1.85 Pd = 17.92 mm = 190.07 mm/hr I(5yrs, tc) FD = 1.85 Pd = 17.92 = 190.07 I(5yrs, tc) mm mm/hr Values of FD for equation 13.3 Duration (min) West Coast East Coast  100 120 150  180 All 5 2.08 1.85 1.62 1.40 1.39 10 1.28 1.13 0.99 0.86 1.03 15 0.80 0.72 0.62 0.54 0.74 20 0.47 0.42 0.36 0.32 0.48 30 0.00 0.00 0.00 0.00 0.00 Pervious area C = 0.62 Q = 0.0164 Impervious area cumec C = 0.9 Q = 0.013 cumec Determination of drain capacity : T = B +2ZY T = A = Y(B + T)/2 3.00 m A = 0.54 2 1/2 + (1 + Z2 ) } = 3.07 P = B + Y{(1 + Z1 ) 2 1/2 2 P 4 Channel area, A = 0.54 m m m m R=A/P R = 0.18 side slope (H : V) = 1 : channel slope, S = 0.002 Channel wetted perimeter, P = 3.074 manning roughness, n = 0.035 Hydraulic radius, R = 0.176 base width, B = 0.6 2 HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. top width water depth, Y = = Q = (1/n) x A x R 2/3 Q V = Q/A 1/2 x So V 3 0.3 , = 0.2164 = 0.401 Q = cumec > 0.2164 Q peak OK! , Q peak = 0.0297 m/s Calculation of Q pre (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, tc tc where = Fc x L / A 1/10 1/5 xS tc = min L = length flow path to outlet (km) L = 0.07 S = slope S = 5.02 A = catchment area, (ha) A = 1 ha = 92.5 (ha) , 58.5 2 (km ) Fc = 58.5 km Fc data tc = 5.672 min km 2 HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. Based on volume 4-chapter 13 of the urban storm m anagement manual on design rainfall, the polynomial approximation of the IDF curves is as followed: R Ln( lt) = a + b ln(t) +c (ln(t)2) + d (ln(t)3) Where: R lt = the average rainfall intensity (mm/hr) for ARI and duration t R = average return interval (years) t = duration (min) a - d fitting constants depending on ARI State Location Perak Bagan Serai Data period 1960 1983 ARI (Year) 2 5 10 20 50 100 Coefficient of the IDF polynomial constants a b c d 4.1689 0.816 -0.2726 0.0149 4.7867 0.4919 -0.1993 0.0099 5.276 0.2436 -0.1436 0.0059 5.661 0.0329 -0.0944 0.0024 5.3431 0.3538 -0.1686 0.0078 5.3299 0.4357 -0.1857 0.0089 The design storm for the durations of time of concentr ation, Tc ; Pervious area I(5yrs,30) = I(5yrs,60) = 107.28 mm/hr 71.60 mm/hr P30 = 53.64 mm P60 = 71.60 mm Duration 5 10 15 20 30 P24h West Coast (120mm) 1.85 1.13 0.72 0.42 0 t = 30 t = 60 HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. The design rainfall depth for short d is given by equation 13.3 : Pd = P30 - FD(P60 - P30) Pervious area FD = 1.85 Pd = 20.42 I(5yrs, tc) = 216.05 mm mm/hr Values of FD for equation 13.3 Duration (min)  100 West Coast 120 150  180 East Coast All 5 2.08 1.85 1.62 1.40 1.39 10 1.28 1.13 0.99 0.86 1.03 15 0.80 0.72 0.62 0.54 0.74 20 0.47 0.42 0.36 0.32 0.48 30 0.00 0.00 0.00 0.00 0.00 Pervious area C = 0.64 Q pre = 0.384 cumec Calculation of result Drain Q pervious Q impervious Qtotal 1 0.016 0.013 0.030 2 0.011 0.005 0.016 3 0.010 0.006 0.016 4 0.016 0.013 0.029 5 0.016 0.000 0.016 6 0.010 0.000 0.010 7 0.011 0.016 0.027 8 0.008 0.010 0.018 9 0.027 0.042 0.069 10 0.022 0.000 0.022 11 0.022 0.000 0.022 Q post = 0.233 HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. 12 0.016 0.011 0.027 13 0.011 0.012 0.023 C1 0.000 0.014 0.014 C2 0.000 0.014 0.014 Q post total 0.233 =  0.384 > Q post OK Concrete drain DESIGN OF DRAIN IN ACCORDANCE TO URBAN STORM MANAGEMENT MANUAL FOR MALAYSIA Total impervious area of site = 0.07 ha Determine overland flow time of concentration overland sheet flow to basin L = 2.5 m S = 2 % to = 107nL /S to = 13.35 min 1 m/s Assume velocity in the drain, V = 1/3 Ld = 27 td = 0.45 n = 0.013 1/2 m min Adopted time of concentration, tc = 13.80 min Based on volume 4-chapter 13 of the urban storm m anagement manual on design rainfall, the polynomial approximation of the IDF curves is as followed: R Ln( lt) = 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 - d fitting constants depending on ARI HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. State Perak Location Data period ARI Coefficient of the IDF polynomial constants (Year) a b c d 2 4.1689 0.816 -0.2726 0.0149 5 4.7867 0.4919 -0.1993 0.0099 Bagan 1960 10 5.276 0.2436 -0.1436 0.0059 Serai - 20 5.661 0.0329 -0.0944 0.0024 1983 50 5.3431 0.3538 -0.1686 0.0078 100 5.3299 0.4357 -0.1857 0.0089 The design storm for the durations of time of concentr ation, Tc ; Pervious area Impervious area I(5yrs,30) = 94.04 mm/hr I(5yrs,60) = 62.75 mm/hr P30 = 47.02 mm P60 = 62.75 mm I(5yrs,30) = 94.04 mm/hr I(5yrs,60) = 62.75 mm/hr P30 = 47.02 mm P60 = 62.75 mm Duration P24h West Coast (120mm) 1.85 1.13 0.72 0.42 0 5 10 15 20 30 The design rainfall depth for short d is given by equation 13.3 : Pd = P30 - FD(P60 - P30) Impervious area FD = 1.85 Pd = 17.92 mm I(5yrs, tc) = 77.9 mm/hr t = 30 t = 60 HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. Values of FD for equation 13.3 Duration (min) West Coast East Coast  100 120 150  180 All 5 2.08 1.85 1.62 1.40 1.39 10 1.28 1.13 0.99 0.86 1.03 15 0.80 0.72 0.62 0.54 0.74 20 0.47 0.42 0.36 0.32 0.48 30 0.00 0.00 0.00 0.00 0.00 Impervious area C = 0.9 Q = 0.014 cumec Drainage design design discharge, Q post = 0.014 try U drain size b= 300 m3/s mm Manning equation 2/3 1/2 Q = AR So /n b = 2y y = b/2 y = 150 mm 2 area of cross section, A = by = 0.045 m S = 0.002 Wetted perimeter, P b +2y = 0.6 m n = 0.013 Hydraulic radius, R = = A/P Capacity, Q = = 0.075 0.029 m3/s > 0.645 m/s < 300 mm 0.003 m3/s Velocity, V = Q/A V use size = 300 mm x 4 m/s OK OK HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. Example of calculation of invert level Ground level, GL = Depth = Gradient = 1.2 1 3.2 m m fall = length x gradient : 500 IL2 = IL1 - fall Drain 1 Length = IL1 IL2 = 47 GL m - depth = 2 m = 2 - = 1.906 m 0.094 Drain 2 Length = IL3 drain 1 2 3 4 5 6 7 8 9 10 11 12 13 22 = 1.906 - = 1.862 m slope 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 IL = invert level m 0.044 invert level(m) 1.906 1.862 1.822 1.742 1.972 1.902 1.826 1.776 1.804 1.946 1.946 1.940 1.884 HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. CATCHMENT AREA HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang. HEROES CONSULTANT  No. 3005, Tingkat Bawah, Desasiswa Lembaran, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang.