Author: workhouse123
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Felling of Trees
The process of a cutting down or knocking down or causing trees to fall to the ground is called the felling of a tree. Trees have to be felled only when they are very close to maturity or have just matured. Generally, trees attain maturity between 50 and 100 years. Trees cut before maturity may…
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Growth of a Tree
A tree grows through the tops of branches. Just within the inner bark, the tree becomes thicker by the formation of cells. A young tree grows taller and thicker every year. The growth is rapid during spring and slower during late summer and early fall. In young trees, hollow cells are alive. During the growing…
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Structure of Exogenous Trees
A cross-section of an exogenous tree is shown in Fig. 10.1. It shows almost distinct concentric rings called annual rings. Pith is the innermost central portion consisting of cellular tissues. The inner annular area surrounding the pith is called heartwood. Heartwood is the one which is used for all engineering works. The portion between the cambium layer and the heartwood…
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TREES
Basic Structure of a Tree A tree consists of a trunk, a crown and roots. The functions of the roots are to implant the tree in the soil, absorb moisture and mineral substances it contains and in turn supply them to the trunk. The trunk supports the crown and serves to provide water and nutrients…
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INTRODUCTION
Timber is a product of wood from felled trees suitable for construction purposes. Timber is one of the oldest and natural civil engineering construction materials. Three terms pertinent to timber one of interest. They are: Wood, as a building material, has a number of valuable properties, viz., relatively high strength, low bulk density, low heat…
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CRACKING IN WALLS
Causes Cracks are frequently found in brick masonry walls due to some of the reasons given below. 17.12.2 Preventive Measures Following are the preventive measures which could minimise the cracks in brick masonry. 1. Foundation Design Depending on the type of foundation soil, the foundation has to be designed and the supporting masonry walls should…
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ECCENTRICALLY LOADED BRICK WALL
In general, walls in buildings are commonly loaded with some eccentricity. Eccentricity may be caused due to one reason or another. Thus, there is a little possibility of establishing an exact relationship between factors which may cause eccentricity. Some of the factors which contribute for eccentricity on brick walls are: Thus a designer has to…
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REINFORCED BRICK WALLS
Ordinary masonry walls are reinforced with iron bars or expanded metal mesh and such walls are called reinforced brick walls. Here, the reinforcement, iron bars or expanded metal mesh are provided at every third or fourth course (Fig. 17.11). Figure 17.11 Reinforcement of brick wall with metal mesh Alternately flat bars of sections about 25 mm…
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SLENDERNESS RATIO AND STIFFNESS
Slenderness ratio is the ratio of effective height or effective length to effective thickness of the masonry unit. Slenderness ratio is an important factor to be considered in the stability of a wall. For solid walls, the effective thickness is the actual thickness of the wall. For the solid walls which are adequately bonded with…
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EFFECTIVE THICKNESS OF WALLS
Effective thickness of a wall is an idealised thickness which reflects the behaviour of the wall. Effective thickness is determined as detailed below. Table 17.4 Stiffness coefficient where Sp = Centre to centre spacing of pier or cross wall wp = Width of pier in the direction of the wall or the actual thickness of cross wall tp = Thickness…