AspectOf Slope • Class I (<15º) • Class II (15º - 25º) • Class III (25º - 35º) • Class IV (> 35º) Basically these guidelines are prepared based on: a) Safety (life and properties) b) Level of environment sensitiveness (sustainability) c) Fulfill the legal requirements 101
Topography Preservation Control Topography Preservation Control in Hilly Areas considered 8 components such as: a) Hilly and highland areas b) Steep areas c) River flow d) Catchment area – lake and pond e) Building arrangement and road f) Unique area with natural beauty or scientific value g) Forest and logging limits h) Seashore area 102
HillyAnd Highland Areas • No development for : a) Areas 150m above the sea or slope >25º b) As stated in Clause 5 • Not encourage development for; a) Identified hilly area for Hutan Simpan Kekal b) Otherwise , PBN must come out with detailed consideration on land conservation, biodiversity aspect and others environment 103
Considerations with acceptance: a)Low and medium density b)Density for of type of land use – 25% only except for bungalows -30% c)Plot ratio -1:1.25 with height max- 5 level only d)Remain the natural topography . Minimize any grading except for infrastructure purpose such as road, electricity, water etc. 104
e)99% must be filled up with greeneries (large and small soft landscapes) f) Building arrangement must be: g)Appreciate the natural contour, river banks, etc h) Setback must be far away from slope i)Building should be designed staggered and considered max slope j) Terrace design is not encouraged k)design and provide drain storm (to cater 100 years rainfalls) l)Development by phase to avoid erosion problems. 1 105
BUILDING DESIGN AND ARRANGEMENT IN PRESERVING NATURAL TOPOGRAPHY •Minimize earthwork near steep slopes •Appreciate the natural skyline •3 – 5 floors only •Minimize earthwork at billowy area •Appreciate the natural skyline •3 – 5 floors only 106
Chapter 4 Earthwork 107
plan 1 section ⚫C u t ⚫ The process of removing soil ⚫ Proposed contours extend across existing contours in the uphill direction C u t 108
plan 1 section ⚫ Fill ⚫ The process of adding soil ⚫ Proposed contours extend across existing contours in the downhill direction C u t Fill 109
Cut & Fill 1 i. The topography map describes the existing slopes of the land, and allows us to draw site elevations in our section cuts. ii. Each line on the topography map represents a change in elevation of 10 feet. So the section at 0ft (the red dashed line above) looks like this in elevation: 110
Cut & Fill 1 iii. Then, by removing the elevation lines, we get the following section for the existing site elevation: iv. The diagrams below represent the area between the existing elevation line and the cut line. First, we mark the land that must be added to the site to achieve our desired land topography. This area is marked "fill." 111
Cut & Fill v. Next, we mark the land that must be removed from the site to achieve our desired land topography. This area is marked "cut." vi. By combining the two diagrams, we can see begin to estimate how much land area must be cut from the site, and how much land area must be filled in the site to level the site for construction. 112
OtherDefinitions 1 ⚫ Compaction ⚫ The densification of soil under controlled conditions, sometime with a specified moisture content ⚫ Topsoil ⚫ Typically the top layer of a soil profile that can range from ~one inch up to ~one foot ⚫Highly organic & subject to decomposition ⚫ Therefore not suitable for structures ⚫ Borrow ⚫When fill material needs to be imported to a site, it is sometimes referred to as borrow 113
Cut & Fill 1 ⚫ Factors that influence your cut & fill grading decisions… ⚫Cost ⚫ Nature of the site including size & shape ⚫Aesthetics ⚫Intricacy of the grading plan ⚫Soil types & suitability for use ⚫Surrounding uses & elevations ⚫ In situations where you cannot balance cut & fill… ⚫ It is generally better to use more cut than fill (unless there are very specific soil requirements such as with an athletic playing field) 114
Cut & Fill ⚫Why? ⚫Importing soil tends to be more expensive than removing soil ⚫A fill condition is usually structurally less stable and more susceptible to erosion & settlement 115
Calculating Cut & Fill 3 methods of estimating cut & fill volumes 1. Average End Area Method 2. Contour Area Method 3. Grid Method Earthwork volumes are typically measured in cubic yards… ⚫ Keep in mind that cubic feet (ft3) must be divided by 27 ft3/yd3 to convert to cubic yards (yd3) 116
Average EndArea Method 1. Take cross sections at regular intervals indicating both existing & proposed contours 2. Calculate the amount of cut & fill at each cross-section based upon existing & proposed grades 3. Multiply average of two adjacent crosssections by the length between them 117
Average EndArea Method V = [(A1 + A2) / 2] xL V = Volume A1 , A2 = Cut/Fill areaof cross sections L = Distance betweenA1&A2 118
Average EndArea Method ⚫Keep in mind that the vertical scale is usually exaggerated by 5 or 10 times ⚫ This is needed because the vertical change is usually a lot smaller than the horizontal scale ⚫ It helps you see what is really going on 119
⚫ The Average End Area Method is best used in linear situations such as: ⚫ Roads ⚫ Paths ⚫ Utility work Average EndArea Method 120
ContourArea Method Using the grading plan with existing & proposed contours: 1. Establish the “no cut - no fill” limit line 2. Separate the area of cut from the area of fill 3. Keeping cut & fill separate… Measure the horizontal area of change for each contour line within limit line 121
ContourArea Method V = A1h/3 + (A1+A2)h/2 + … + (An-1+An)h/2 +Anh/3 V A1 , A2 ,An h =Volume = Areaof horizontal changefor eachcontour = Vertical distance betweenareas If h equals i (the contourinterval) Thentheequationcan besimplified as follows: V = i(A1+ A2 + … + An) V A1 , A2 ,An i =Volume = Areaof horizontal change foreachcontour = Contourinterval This form of theequation often overestimatesvolumes… 122
ContourArea Method 123
Step 1: No Cut - No Fill Line 124
Step 2: Line Between Cut & Fill 125
Step 3: MeasureArea ofCut & Fill for each contour line cut fill 126
For the 72’ Contour Line ⚫Approximate area of C u t = 284 ft3 ⚫Approximate area of Fill = 1,056ft3 Repeat for Each Contour Line 127
Total Cut & Fill ⚫ Approximate Total C u t = 1,280 ft3 ⚫ Approximate Total Fill = 3,216 ft3 Divide by 27 ft3/yd3 to find square yards Cut = 47.4 yd3 Fill = 119.1 yd3 128
ContourArea Method ⚫The Contour Area Method is best used for large, relatively uncomplicated grading plans as well as for calculating the volume of water in lakes or ponds 129
Grid Method Also known as the Borrow Pit Method 1. Create a grid over the area to be graded ⚫ Smaller cells → More accurate ⚫ 2. For each grid cell Find the average change in elevation by determining the elevation difference for all four corners of the grid cell 3. The volume is calculated by ⚫ ⚫ Adding the averaged cut & fill volumes separately Then multiplying by the area of one grid cell 130
Step 1: CreateGrid 131
Step 2: FindAvg. Change in Elevation (existing spot) proposed spot 132
Step 2: FindAvg. Change in Elevation Vavg = (h1 + h2 + h3 + h4) / 4 Vavg = 3.5+4.4+2.6+3.3 4 Vavg = 3.45 feet of cut Repeat for each grid cell… 133
Step 3: Add Cuts/Fill Separately & Multiply by Grid Cell Area Grid Cell #1 = 3.45 feet cut Grid Cell #4 = 2.30 feet cut Grid Cell #2 = 3.48 feet cut Grid Cell #5 = 2.35 feet cut Grid Cell #3 = 2.50 feet cut Grid Cell #6 = 1.78 feet cut ⚫ Add cuts & fills separately ⚫In this case, the site is all cut ⚫Total of Grid Cells = 15.85 feet cut ⚫ Multiply by the Area of one Grid Cell ⚫15.85’(100’)(100’) = 158,500 ft3 → 5,870 yd3 134
The Grid Method is best used for complex grading projects and urban conditions To use the grid method to calculate your cut and fill construction projects, do the following steps: 1. Lay your plan out on the flat surface. Then with a large T-square, draw set of equally spaced horizontal and vertical lines across your plan. 2. At each intersection of the horizontal and vertical lines, determine the existing and the proposed elevation 3. For each intersection subtract the existing elevation from the proposed elevation. Positive numbers are fill. Negative numbers are cut. 4. For each cell, add the four cut and fill numbers together and divide them by 4.0 to calculate the average cut or fill depth for that cell. 5. Multiply the average cut or fill depth by the number of square feet in the grid cell to get the cut or fill volume in cubic feet. 6. Add all of the cut volumes up and divide that number by 27 to get the total cut for the site in cubic yards. 7. Add all of the fill volumes up and divide that number by 27 to get the total fill for the site in cubic yards. 8. To calculate the import or export, subtract the fill volume from the cut volume. If the result is a positive number, you have more cut than fill and you will need export material from your site. If the numbers negative, you will need to import dirt onto the building site. Grid Method 1 135
Chapter 5 Local Environment Factor 136
1 137
What is the name of this factor? ⚫A microclimate is when the climate in a small area is different to the general area around it ⚫Many different things can cause this ⚫(Climate is the average weather conditions of a place over a long period of time – remember??!!) 138
What local features affect temperature and wind? 1 1. Physical Features 2.Shelter 3. Surface 4.Building 5. Aspect 139
The effect of hedges/shelter This side of the hedge is in shade. It would be cooler This side of the hedge faces the su n. It would be warmer • Trees, hedges, walls, buildings and even hills can provide shelterfrom the wind. • Wind speed may be reduced and its direction changed. • Places sheltered from cold winds will be warmer. 140
The effect of shelter 1 This side of the wall is sheltered from the wind. It would be warmer This side of the wall is exposed to the wind. It would be cooler 141
The effect of physical features Water areas like lakes have a cooling effect on the land. Trees can also shade the land. It would be cooler 142
The effect of surface 1 Light surfaces such as grass reflect heat. It would be cooler Dark surfaces such as tarmac store heat. It would be warmer • Colour ofthe ground surface affects warming • Dark surfaces such as tarmac and soil absorbs more radiation than lighter coloured surfaces. • Lighter colour surfaces such as grass will reflect more radiation. 143
The effect of buildings 1 Buildings store heat and give it out in the afternoon. Buildings close together can break up winds. It would be warmer, especially in the afternoon • Buildings give off heat that has been stored from the sun during the day which leaks out from their heating systems. • Temperatures near buildings may be 2 to 3 degrees higher. • Buildings also break up the wind and can reduce wind speeds by up to a third. • Sometimes wind can increase in speed as it rushes through buildings. Sometimes wind speed can increase if it rushes around buildings. Here, it would be cooler 144
The effect of aspect 1 If a place/person is facing North, then they will get less sun. It would be cooler If a place/person is facing South, then they will get more sun. It would be warmer • The direction in which a place is facing is called its aspect. • Placing facing the sun will be warmer than those in shadow. 145
Microclimate Factor 1 a) Wind b) Humidity c ) S u n , Shadow d) Heat and Ventilation e) Sound and Noise The information are important for: Orientation of structures Shielding of exposure to sun Equipment for cooling and heating Building materials Cover and planting Light conditions 146
Microclimate is influenced by: a) Topography b) Cover c) Ground surface d) Man-made forms 1 147
HEAT ANDVENTILATION 1 ⚫The FUNDAMENTAL phenomenon to be considered is the HEAT BALANCE ⚫Heat is exchanged by radiation, conduction and convection. ⚫There are THREE(3) main characteristics to be considered: a) albedo b) conductivity c) nature of air movement 148
a) Albedo ( Resapan dan Pantulan) i)Albedo with 1.0 – a perfect mirror, reflecting back everything that shines on it, heat and image ii) Albedo with 0 – a black surface, reflect nothing and soaking all heat 1 149
b) Conductivity (hadlaju haba dan bunyi melalui sebarang peralatan) Heat flows rapidly through substances of HIGH Conductivity. Ex: A piece of warm metal feel much HOTTER than wood of the same temperature. The conductivity of natural material decreases as these material driers, less dense or more porous. 1 150