## Posts

Showing posts with the label Civil Engineering

### Penetration Test

Penetration Test  The penetration test a look at determines the hardness or softness of hydrocarbon by measuring the depth m tenths of an mm to that a regular loaded needle can penetrate vertically m 5 seconds. Sample eighteen maintained at a temperature of 25°C " The idea of a penetration take a look at is shown IN Fig one Indian normal institution has standardized the instrumentation and test procedure. Penetration Test Diagram Penetration Test Process The bitumen lS softened to a poor rm g consistency stirred thoroughly and poured into containers to a depth of at least 15 mm in excess of the expected penetration. The sample containers are then placed in a temperature-controlled water bath at a temperature of 25 degrees C for one hour. The sample with the container is taken out and the needle is arranged to make contact with the surface of the sample. The dial is set .to zero or the initial reading is taken and the needle is released for 5 seconds. The final reading is taken on

### Limitations of Terzaghi Theory

Limitations of Terzaghi Theory The value of the coefficient of consolidation has been assumed to be constant.  The distance d of the drainage path cannot be measured accurately in the field. The thickness of the deposit is generally variable, and an average value has to be estimated.  There is sometimes difficulty 1n locating the drainage face, and sometimes thin previous seams that can act as good drainage faces are missed in the boring operations. The equation is based on the assumption that the consolidation is one-dimensional. In the field, the consolidation is generally 3-dimensional. The lateral drainage may have a significant effect on the time rate of consolidation. The initial consolidation and secondary consolidation have been neglected. Sometimes these form an important part of the total consolidation. In actual practice, the pressure distribution may be far from linear or uniform.

### Inverted Siphons

Inverted Siphons When a main dips below the hydraulic grade line, it's referred to as associate inverted siphon. The purpose is to carry the sewer under the obstruction, such as roadway, railway, stream, river, etc. and regain as much elevation as possible. The sewage through such a pipeline (or inverted siphon) will flow under pressure which is greater than atmospheric pressure. Inverted siphons should be resorted to only where other means of passing the obstruction are not feasible, as they require considerable attention in maintenance. As the siphons are depressed below the hydraulic grade line, maintenance of self-cleansing velocity at all flows is very important. Inverted siphon Designing The construction of the siphon should be simple. The changes in direction should be easy and gradual. It is necessary to have a seIf-cleansing velocity of 1 meter per second for the minimum flow to avoid deposition in the line. The siphon should have two or three pipes of differe

### Sewage Farming In India

Sewage Farming In India The sewage effluent can also be disposed of by applying it to the land. The percolating water may either Join the Water table or be collected below by a system of underdrains. This method can then be used for irrigating crops. And hence termed sewage farming , Since it not only disposes of the sewage but also helps in increasing crop yields (by 30% or so) as the sewage generally contains a lot of fertilizing minerals and other elements. Fertilizing elements like N, P, K, etc. do help in increasing the yield of cash crops like cotton, sugarcane, plantain, etc.  However, crops to be eaten raw or which do not have any skin to be removed before eating should not be grown on sewage farms, although this is seldom practiced by the farmers. But the sewage effluent must be treated before being used in sewage farming . In order to lay down the limiting standard for sewage effluents and the degree of treatment required, it is necessary to know all the consequences. Sewage

### Comminutors Definition

Comminutors Definition Comminutors or Shredders are the patented devices, which break the larger sewage solids to about 6 mm in size when the sewage is screened through them. Such a device consists of a revolving slotted drum, through which the sewage is screened (Fig.) Cutters mounted on the drum, shear the collected screenings against a comb until they are small enough to pass through 5 mm to 10 mm ‘wide slots of the drum. These are usually arranged in through 5 mm to 10 mm wide slots of the drum. These are usually arranged in pairs to facilitate repairs and maintenance.  Comminutors are of recent origin and eliminate the problem of disposal of screening, by reducing the solids to a size that can be processed elsewhere in the plant. They should always be preceded by grit chambers to prevent their excessive wear.

### Settling Principle And Purpose

Settling Hello Friend Today  We Are Discuss About Settling Principle And Purpose.  Settling  is an Important topic in civil engineering The solid-liquid separation process in which a suspension is separated into two phases: Clarified supernatant leaving the top of the sedimentation tank (overflow). Concentrated sludge leaving the bottom of the sedimentation tank (underflow). purpose of Settling  To remove the coarse dispersed phase.   To remove coagulated and Hocculated impurities. To remove precipitated impurities after chemical ' treatment. To settle the sludge (biomass) after activated sludge process/tricking filters Principle of Settling Suspended solids present in water having a specific gravity greater than that of water tend to settle down by gravity as soon as turbulence is retarded by offering storage. Basin in Which the flow is retarded is called the settling tank. The theoretical average time that the water is retained within the subsidence tank i

### Drop Manhole

Drop Manhole It is a special type of manhole on a sewer line which is Constructed to provide a connection between a high-level branch sewer to a low-level main sewer. When, a branch sewer enters a manhole by, more than 0.5 to 0.6 m above the main sewer, the sewage is not allowed to fall directly into the manhole. Instead, the sewage 0f the branch sewer is brought into the manhole of the main sewer either by inclined pipe (inclined at 45°) or through a downpipe (vertical pipe). In the former case, it is known a ramp while in the latter case it is known as a drop manhole . Fig. shows details of a circular drog manhole. The branch sewer is joined to the manhole of the main sewer through a vertical pipe (or drop pipe). The sewage coming from the branch sewer flows down in the vertical pipe and emerges out through a horizontal pipe just above the benching. A plug is provided at the point where the branch sewer, if prolonged straight, intersects with the vertical wall of the manhole. The pro

### Muller-Breslau principle

Muller-Breslau principle Muller-Breslau principle is the most essential tool in obtaining influence lines for statically determinate us well u statically indeterminate structures. The method is based on the concept of the influence line as a deflection curve. The Muller-Breslau principle may be stated as follows. If an internal stress component or a reaction component is considered to act through some small distance and thereby deflect or displace a structure, the curve of 1 the deflected or displaced structure will be, to some scale, the influence line for the stressor reaction component. Muller-Breslau principle is applicable  1. Statically determinate beams 2. Statically indeterminate beams The Muller-Breslau principle influence theorem for ‘ statically determinate beams may be stated as follows: The influence line for an assigned function of a statically determinate beam may be obtained by removing ‘ the restraint offered by that function and introducing a directly related gener

### Highway Pavements

Highway Pavements This Topic Highway Pavements From Highway Engineering And Civil Engineering. The surface of the road ought to be stable and non-yielding, to permit the serious wheel lot of road traffic to maneuver with the least doable rolling resistance. The paved surface ought to even be even on the longitudinal profile to alter the quick vehicles to maneuver safely and well at the look speed.  At high moisture content, the soil becomes weaker and soft and starts yielding under heavy wheel loads, thus increasing the resistance to traction. The earth road may not be able to fulfill any of the above requirements, especially during the varying conditions of traffic and weather changes. Therefore a pavement consisting of superior and stronger materials is laid over the prepared earth surface which could fulfill the above requirements. The objective of laying a pavement is to support the wheel loads and to transfer the load stresses through a wider area on the soil subgrade below. Thus

### Trickling Filter Process

Trickling Filter Process In trickling filter, sewage is allowed to sprinkle or trickle over a bed of course, rough, hard filter media and it is then collected through the under drainage system. Spray nozzles or rotary distributors are used for this purpose. The biological purification is brought about mainly by aerobic bacteria which form a bacterial film, known as biofilm, around the particles of the filtering media,Though, trickling filter is classified as ah aerobic treatment device, the microbial film the slime layer formed on the 111ter medium is aerobic to a depth of only 0 1 to 0.2 mm and the remaining part of the 111m 18 anaerobic. As the wastewater flows over the microbial film, the soluble organic material in the sewage is rapidly metabolized while the colloidal organics are adsorbed onto the surface. In the outer portions of the biological film, the organic matter is degraded by aerobic microorganisms. Since the concentration is higher at the outer ' layer, the micro-o

### Working Of Septic Tank

Working Of Septic Tank In the grit chamber, sand, grit, settleable inorganic matter, etc. settle before sewage enters the anaerobic chamber. In the anaerobic chamber, organic solids settle at the bottom of the tank where anaerobic bacteria act on it and convert complex unstable compounds into simple stable compounds.  Nitrogen is converted into ammonia and the mixture becomes alkaline. The colloidal matter is flocculated and then liquefied and finally digested. Discharged organic matters are also digested.  Due to these processes, there is a considerable reduction in the volume of sludge and it settles at the bottom of the tank. The clarified sewage discharges through the outlet.  Cases are liberated due to sludge digestion which rises to the surface constantly in the form of bubbles. These bubbles carry small particles of decomposed sludge and a floating layer of scum (black in color) is formed on the surface.  The scum contains anaerobic bacteria that attacks the undissolved componen

### [ FBAS ] Fixed-Bed Biofilm Activated Sludge

Fixed-Bed Biofilm Activated Sludge The FBAS is  Called Fixed-Bed Biofilm Activated Sludge.  The FBAS process is essentially an activated sludge-attached growth process where the plant roots provide the area for the biofilm to develop and grow. The aeration system is divided into a series of biological reactors where fixed biofilm is maintained in every stage of the process.  As the influent travels through the cascade, the available nutrient quantity is consumed and as a result, the composition of the ecosystem fixed in the biofilm changes from reactor to reactor, gradually adapting itself to the decreasing nutrient concentration. In each cascade stage, a specially adapted ecosystem will form, thus maximizing the decomposition of contaminants. As reported, some plants with such technologies have been set up in different countries including Hungary, China, France, etc in the last 10 years. However, it will be useful to demonstrate this project under Indian conditions. Fixed-Bed Biofil