Engineering Updates

There are two types of bars in a RCC column i.e. longitudinal bar and horizontal bar. In horizontal bar, the stirrups and ties are utilized in column. Stirrup is also known as ring, shear reinforcement, etc. To form stirrup for column, it is necessary to work out the cutting length of bar for stirrup as well as calculate the number of stirrups and the size of stirrup. It can be performed in following 4 easy steps.  Find out the size of stirrup Compute the cutting bar length for stirrup Compute the number of stirrups  Bending the bar in stirrup’s shape 1. Find out the Size of Stirrup Suppose, the column size is 20″ x 40″. The concrete clear cover for reinforcement of column is taken as 1½”. The length of stirrup should be 40″-2×1½”=37″ and width 20″-2×1½”=17″. Therefore, the size of the stirrup is 37″x17″. 2.Work out Cutting-Bar-Length for Stirrup There exist actual bar length and cutting bar length. The actual bar length of sti...

The entire process of structural planning and design requires not only imagination and conceptual thinking but also sound knowledge of practical aspects, such as recent design codes and bye-laws, backed up by ample experience, institution and judgment. It is emphasized that any structure to be constructed must satisfy the need efficiency for which it is intended and shall be durable for its desired life span. Thus, the design of any structure is categorizes into following two main types:- 1. Functional design 2. Structural design FUNCTIONAL DESIGN: The structure to be constructed should primarily serve the basic purpose for which it is to be used and must have a pleasing look. The building should provide happy environment inside as well as outside. Therefore, the functional planning of a building must take into account the proper arrangements of room/halls to satisfy the need of the client, good ventilation, lighting, acoustics, unobstructed view in the case of community h...

Nos. of piles needed will depend upon the total vertical load from column / pile capacity  Pile group of three,four ,five ,six or more can be adopted based on nos of piles required.  Any moment acting from column is also accounted (as it will effect the exterior piles most)  by addtional +ve reaction on one side and -ve reaction on other side piles due to moment  Minimum c/c spacing between piles shall be:    2*D - - - for piles resting on rock  2.5*D - - - for piles deriving their strength predominantly from end bearing( predominantly sandy strata)  3*D - - - for piles deriving their strength predominantly from skin friction( predominantly clayey strata)  (d= Pile shaft diameter)  Pile cap can be designed by bending theory .Draw a line at mid depth of    pile cap .The column load is taken to be dispersed at 45 degrees into  pile cap upto its mid depth acting downwards.The reaction from piles  shall also b...

TOP 10 REQUIREMENTS TO BE A SUCCESSFUL CIVIL ENGINEER CIVIL ENGINEERING REQUIREMENTS: THESE ARE THE TOP 10  CIVIL ENGINEERING REQUIREMENTS   TO BECOME A SUCCESSFUL CIVIL ENGINEER: 1. TESTS OF BUILDING MATERIALS: A good civil engineer should have proper knowledge of different tests of building materials. Some important tests are listed below. Concrete Test :  Slump test,   compression test ,  split tensile test, soundness etc. Soil Test:   Core cutter test ,  compaction test,  sand replacement test, triaxial test, consolidation test etc. Bitumen Test:  Ductility test, softening point test, gravity test, penetration test etc. 2. INVESTIGATION OF SOIL: Various soil tests are conducted to determine the settlement and stability of soils before starting a construction. So as a civil engineer, you should have enough knowledge of these tests which are performed at the site. 3. USES OF SURVEYING INSTRUMENTS: Usag...

SPT Value Correction – The observed SPT values as measured in the field are not reliable due to multiple factors and therefore need  to be corrected. Two types of corrections which are usually applied for this task are: dilatancy and overburden pressure corrections. Dilatancy correction –    The dilatancy correction can only be applied when the test is conducted in fine or silty saturated sand when recorded blow count is greater than 15. The correction factor as suggested by Terzaghi and Peck (1967) is as follows. Where, N o  = Observed N-Value N c ‘ = Corrected N – Value In no case, the corrected values shall be greater than twice the observed values. Overburden correction –  With the increase in confining pressure in sands N-Values are increased considerably. As a result values of relative density other than actual values are obtained and therefore, the observed values are to be corrected. The N-Values at shallow depths are under-estimated and at ...

HOW TO CALCULATE BEARING CAPACITY OF SHALLOW FOUNDATION IN SAND FROM SPT VALUES OR N-VALUES  (IS-6403) STEP-1 Perform standard penetration test  on the location for which you want to calculate bearing capacity. This is done as per standard procedure given in IS-2131. Standard penetration test must be done at every 75 cm in vertical direction. STEP-2 Decide the depth, width and length of foundation for initial calculation. This is a trial and error process. In the first attempt, you can never get the exact size of foundation which will satisfy all of your needs. STEP-3 Apply necessary  corrections to the standard penetration test values . Calculate the cumulative average value of corrected SPT values from the base level of foundation to a depth equal to 2 times the width of foundation. STEP-4 Correlate the above cumulative average SPT value with the fig given below to find out the corresponding angle of shearing resistance (ϕ). Relation between ph...

According to the Concrete Reinforcing Steel Institute (CRSI), “form work and its associated labor is the largest single cost segment of the concrete structural frame—generally more than 50%.”           • maintaining constant depth of horizontal construction           • maintaining constant spacing of beams and joists           • maintaining constant column dimensions from floor to floor           • maintaining constant story heights Standard Forms Since most projects do not have the budget to accommodate custom forms, basing the design on readily available standard form sizes is essential to achieve economical form work. Also, designing for actual dimensions of standard nominal lumber will significantly cut costs. A simplified approach to form work carpentry means less sawing, less piecing together, less waste, and less time. this results in reduced labor and mated costs and fewer op...