Basics In Civil Engineering

  Measurement of distances with Chain and Tape on ground with Direct and Indirect Ranging   Principle of Chain Surveying:            The principle of chain surveying is derived from principle of triangulation. The area to be surveyed is divided into a number of triangles and the sides of the triangle are measured in the field. To get good results in plotting, the framework should consist of triangles which are as nearly equilateral as possible. Preferably all the sides of a triangle should be nearly equal having each angle nearly 60 o  to ensure minimum distortion due to errors in measurements of sides and plotting.   Theory:        The process of establishing intermediate point on a straight line between two end points is known as  ranging . Ranging must be done before a survey line is chained. It may be necessary to establish a number of intermediate points prior to chaining when chain line is much longer. Ranging may be done by direct observation by the naked eye or by lin

  Rolled Steel Sections       Structural steel sections are hot rolled into different shapes and sizes to form the different sections. Cross section and size are governed by functional requirements, dimensional and weight capacity of rolling mills, arrangement of material for optimum structural efficiency. In a rolling mill molten steel from furnace is poured into continuous casting system where steel solidifies but it is not allowed to cool completely. Then hot steel passes through series of rollers. Such series of rollers squeezes steel into desired cross sectional shape. If the load to be resisted is small single rolled steel sections are used. If the single section is insufficient, single sections are combined or built up with angles/ channels/ I sections with or without cover plates and /or laced, providing sufficient resistance to heavy loads. Most commonly used hot rolled steel shapes are as follows: 1. Rolled Steel I -Sections 2. Rolled Steel Channel Sections 3. Rolled Steel An

Approximate Estimate: Approximate estimate is also called as preliminary estimate. It is an approximate or rough estimate prepared to obtain the cost of a project in short time, without taking out actual quantities.   Purpose of Approximate Estimate: 1. For government project approximate estimate is required for              administrative approval. 2. Due to approximate estimate it is easy to check/ study feasibility        of project. 3. Whether the new project is beneficial and to study cost- benefit           ratio approximate estimate is necessary. 4. When one has to fix the rent for the property it is necessary to             know the approximate estimate. 5. This type of estimate is helpful to fix the tax. 6. For existing building if valuation has to be done approximate              estimate plays the important role.   Types of Approximate Estimate: 1.    Plinth Area Method 2.    Cubical Content Method 3.    Service Unit Method 4.    Typical Bay Method