Construction Technology - Site Terms, Substructure Design and Basement, Superstructure and Roofs - Coursework Example

Portfolio: Construction Technology Name and Course Code Institution Name Department Name Insert Your Name Insert Your ID Instructors Name 15th March 2009 Table of Contents 1.0 Introduction………………….……………………………………………3 2.0 Site Conditions……………………………………………………………3 2.1 Soil Type & Constraints……………………………..……………3 2.2 Temporary and False Walls….……………………………………4 2.3 Retaining Walls……………………………………………………4 2.4 Ground stabilization………………………………………….……5 3.0 Substructure Design and Basement………………………….……………6 3.1 Foundation…………………………………………………………6 3.2 Soil Support………………………………………………………..7 3.3 Control of Ground Water/De-watering…………………………….8 3.4 Methods of fabrication…………………………….……………….9 4.0 Superstructures……………………………………………….……………9 4.1 Structural Frames and Masonry Structures…………..…………….9 4.2 Fundamental properties of structural materials…….…….……….10 4.3 Principles of Structural Design………………………..…………..10 4.4 Connectors………………………………………….….………….11 4.5 Reinforcement materials and design…………………..…………..11 4.6 Fire protection and Environmental Concern…………..…………..12 5.0 Roofs…………………………………………………………...………….12 5.1 Selection……………………………………………………………12 5.2 Design………………………………………………………………13 5.3 Construction and Performance of Roofing Systems………………..13 6.0 Bibliography………………………………………………………………..15 1.0 Introduction The construction industry requires specific understanding of specific technology in succeeding in completion of a building. Thus, the aim of this report is to analyze construction of a building through understanding the site conditions, substructure, superstructures and roofs. 2.0 Site Conditions 2.1 Soil Type & Constraints Condition of the ground that a building should be constructed plays a paramount role in determining the success of the building. Conditions range from the basic nature of environment to codes and regulations that are set to guide the construction process. The type of soil in the site determines approach that will be used to support the building because of its load holding capability, drainage capabilities and environmental impact. The nature of site is controlled by previous activities that the ground was used for e.g. deposit site for wastes. This calls upon appropriate measures to ensure that the building would be supported. For example, sand and gravel have good drainage capabilities while clay and black soils have poor drainage capabilities. Nevertheless, the site of construction is guided and controlled by constraints: such as statutory directives and municipality or local authority descriptions plus adjacent building. Building in the city centre requires different conditions compared to building in a secluded region e.g. rural areas. Moreover, the construction requires services such as sewage and electricity, which have to be fulfilled before construction begins. 2.2 Temporary and False Walls Generally, false work are the temporary structures that are used in building construction and are used to supported arched or spanning structures for a period that will enable the building to sufficiently support itself. The temporary or false works includes scaffolding and formwork that is used to mould concrete to give a desired shape. Figure 1 (below) shows a door spanning that is supported by false work to support the concrete beam. Figure 1: Door spanning supported by metal false work (sketch) 2.3 Retaining Walls A retaining wall is a structure that is used to hold back soil from a construction area. These walls prevent erosion and support any vertical changes that may occur. Originally, the most favored approach towards achieving the requirements of retaining walls was poured-in-place walls but has been replaced new types of retaining walls. Construction of the retaining walls put into consideration retaining material from moving down slope or forward because of gravity. The aim of the retaining walls is to ensure that lateral earth pressure is put behind that wall that depends on cohesive strength, angle of internal friction of the retained material and the magnitude and direction of movement that the retaining wall undergoes. Retaining walls are grouped into modes of operation e.g., gravity walls and cantilever walls as shown in figure 2. Figure 2: Retaining walls 2.4 Ground stabilization Ground stabilization is an act that ensures that the location of construction is stable and can withstand any movements that can occur or ensure that the soil/ ground can support the building. Original approach towards making the ground stable was through compaction and adding rocks and harder materials into the ground. However, technological advancement has made introduction of metallic appliances such as mesh into the soil to aid ensuring stability of the building. 3.0 Substructure Design and Basement The substructure and basement should combine the interactions of walls, temporary and permanent propping, construction sequence controls and control of ground water in a holistic approach. The substructure is the core point in ensuring that the building supports all loads and requirements of the construction process and fulfilment of the result of the building. 3.1 Foundation Foundation is an important aspect in building construction and the structure itself because it should be capable to transfer the load of the building to the earth. In most cases, foundations are grouped into two categories depending on the requirements that it should fulfil, they include shallow and deep foundations (Litchfield, 2005). The shallow foundations are usually a meter long and embedded into soil. Types of the shallow foundations are the spread footing and slab-on grade foundation. Deep foundations transfer the load through an upper weak layer to a deeper and stronger layer of soil. Some examples of deep foundations are the drilled shafts, piers and helical piles (British Standards Institution, 2005). Figure 3: Shallow and Deep foundation sketches 3.2 Soil Support Soil support is the way that the soil that is within the excavated region is supported to prevent collapsing. This is because the location of sites may be small and unable to provide and accommodate cut slopes of battered excavations (Tomlinson, 2001). Moreover, certain types of soil e.g. over-consolidated clays are usually time-dependent. Even though the space is adequate, cost penalty for slope failing is measured against the cost of retention of the soil. Temporary structures and false works can be used to control and support the soil. 3.3 Control of Ground Water/De-watering The level of water within a construction site should be minimal to ensure the quality, cost and life span of the building is guaranteed. The utilization of evaporation and pumping: a process, which usually occurs during the development phase, reduces the water table of the site. Some common methods that are used in dewatering or improving ground water content are through deep well, wellpoint and eductor systems. Wellpoint watering is useful in stratified soils and can be used to control ground water to a level of 20″. Deep well dewatering is used to control water of between 20″ to 100″ and in which large volumes of water should be controlled. Moreover, it is able to penetrate strata impervious and enables drainage of large areas. Trench tile dewatering is convenient and effective because there is no use of suction manifold and its installation is faster when compared with wellpoint dewatering system. Figure 4: Wellpoint and deep water dewatering 3.4 Methods of fabrication The most common fabrication method is applied in the metal industry in the shaping, cutting and bringing together raw materials in constructing a structure. Bringing together beams, connectors, and incorporation the appropriate design ensures that the success of the building in its operation and durability plus anaesthetics characteristics is guaranteed (Foster & Harrington, 2000). 4.0 Superstructures 4.1 Structural Frames and Masonry Structures These are the most commonly used building systems. These frames come in forms of beam and post, slab and wall systems or a combination of the various structural members can be used. Most frames bring into play vertical bearing and horizontal spanning; however, they are controlled by joinery. In those structures that use beam and frames, the vertical and horizontal members are connected by simple joints and transferring of loads is independent. On the other hand, rigid frames are connected by rigid and moment resistance joints. Some common structural frames are the wood, steel and concrete. Figure 5: General design of structural frame 4.2 Fundamental properties of structural materials Structural frame defines the life period of the building and capacity to fulfil its requirements. Materials that are used for the construction should ensure that it champions the requirements of the building within the minimal cost. The materials should be light weight with high strength. The lightweight will reduce the load of the building while the high strength will ensure that the load of building is within the given standards. Moreover, other paramount properties are that the materials should be corrosion resist and ageing resistant to increase the durability of the building. Additionally, it should provide insulation and UV protection and at the same time be easy to install and have low maintenance. 4.3 Principles of Structural Design For stability purpose and quality of the entire construction, principles of design should be incorporated in the development of the building. The beams should be balance in that external and internal force is zero and the sum of moments is zero. The structures should be honest in that all forces have specific natural paths bringing into consideration nature of discrete and curved structures. Additionally, the connection between the structural elements should be continuous to ensure effectiveness of the structures to ensure that it fulfils its requirements. 4.4 Connectors Connectors play an important role in boosting the strength of a structural frame and ensuring that all beams are in place. Common means that are used for connections are nails for timber based structural frames. For metal-based frames, nuts, bolts, screws and welding (connection through coalescence) are used to ensure that the strength and the beams are in balance. Other connection approaches may include tying e.g. with the help of wires and other metallic materials. 4.5 Reinforcement materials and design Reinforcement improves the strength of structures and components that are used in the construction industry. Glass and concrete are usually reinforced; however, the commonly reinforced component in the structure is the concrete that contributes into the formation of foundations, beams, columns, walls, slabs and frames (British Standards Institution, 1997). In most cases, the reinforcement can take two approaches cast in-situ and pre-cast concrete. Hence, successful implementation and designing of efficient reinforcement guarantees optimal building structures contributing in impacts towards the success of the construction in terms of cost and time. 4.6 Fire protection and Environmental Concern Appropriate measures should be in place to guarantee fire safety in eliminating and preventing wide spread of the fire, if it may occur. Introduction of fire safety measures systems such as smoke detectors, alarms, sprinklers, fire extinguishers and the structural design of the building define the success of fire prevention. Walls should be built with fire-retarded materials and inclusion of smoke flow protection and incorporation of measures such as cladding improves the standards of fire safety. Moreover, the building should be environmental friendly to reduce or eliminate negative impacts of the building to the environment. The building materials, waste disposal, sewage management and electricity or energy that is been used should be environmental friendly. 5.0 Roofs Roof is the uppermost covering of any building. The aim of the roof is to protect the contents of the building from weather conditions. The main components that defines the success of a building is the material, durability and construction it self. 5.1 Selection The selection of the roof that should be constructed depends on the nature of construction, material that will be used and durability of the entire building. This will ensure that the building fulfils its requirements and at the same time ensures that the building spans the period that it is required. Construction of roofs of industrial buildings and house requires specific considerations. Moreover, the materials that the roof will be built with define the success of the construction. 5.2 Design The design of the roof plays an important role in ensuring that the requirement of the building is achieved. There are various designs that can be used in the construction industry. Some of the roofing designs that are commonly used are shown the sketches below (figure 6) (Wagner & DeKorne, 2005). Figure 6: Some roofing designs 5.3 Construction and Performance of Roofing Systems The design and selection of the type of roofing is defined by the use of the building. Some roofs are tall while others are flat. For example, the flat roofs are usually used for shades while the gable roofs are usually used for the construction of houses. The construction process brings into consideration the material that can be used. Some common materials that are used for roofing include thatch, tiles, shingles, membranes and metals. Factors that guide towards picking the appropriate material include the utilization of the building, cost and durability. However, the common means that are used to select the appropriate material includes durability of the material, insulation and resistant to weather capability, and capability to provide drainage means. Moreover, appropriate utilization of the materials and design of the roof defines the beauty of the entire building. 6.0 Bibliography British Standards Institution, 1997, BS 8110-1:1997: Structural use of concrete: Code of Practice for design and construction, London: Office Stationery. British Standards Institution, 2005, BSI BS 5628-3 Code of practice for the use of masonry, London: Office Stationery. Foster, J. & Harrington, R., 2000, Structure and Fabric Part 2. 6th Ed., London: Longman. Litchfield, M., 2005, Renovation: Completely Revised and Updated, 3rd Ed. London: Taunton Press. Tomlinson, M., 2001, Foundation Design and Construction, 7th Ed. New York: Prentice Hall. Taylor, G., 2000, Materials in Construction, 3rd Ed. London: Longman Higher Education. Wagner, J. & DeKorne, C. 2005, Barns, Sheds and Outbuildings: Plan, Design, Build, London: Creative Homeowner. Read More