one for all

Tuesday, August 9, 2011

concrete mix design..........


Good quality concrete starts with the quality of materials, cost effective designs is actually a by-product of selecting the best quality material and good construction practices. Following are 10 Things to remember during Concrete Mix Design and Concrete Trials.

1. ACI and other standards only serves as a guide, initial designs must be confirmed by laboratory trial and plant trial, adjustments on the design shall be done during trial mixes. Initial design “on paper” is never the final design.

2. Always carry out trial mixes using the materials for actual use.

3. Carry out 2 or 3 design variations for every design target.

4. Consider always the factor of safety, (1.125, 1.2, 1.25, 1.3 X target strength)

5. Before proceeding to plant trials, always confirm the source of materials to be the same as the one used in the laboratory trials.

6. Check calibration of batching plant.

7. Carry out full tests of fresh concrete at the batching plant, specially the air content and yield which is very important in commercial batching plants.

8. Correct quality control procedures at the plant will prevent future concrete problems.

9. Follow admixture recommendations from your supplier

10. Check and verify strength development, most critical stage is the 3 and 7 days strength.

Wednesday, August 3, 2011

IMP POINTS FOR PRESENTATION.....


Important Points from Presentation
A design engineer’s responsibility should include assuring the structural safety of the design, details, checking shop drawing.

Detailing is as important as design since proper detailing of engineering designs is an essential link in the planning and engineering process as some of the most devasting collapses in history have been caused by defective connections or DETAILING. There are many examples explained in the book” DESIGN AND CONSTRUCTION FAILURES by Dov Kaminetzky.

Detailing is very important not only for the proper execution of the structures but for the safety of the structures.

Detailing is necessary not only for the steel structures but also for the RCC members as it is the translation of all the mathematical expression’s and equation’s results.

For the RCC members for most commonly used for buildings we can divide the detailing for Slabs-with or without openings.(Rectangular,circular,non-rectangular-pyramid slab,triangular etc) balcony slab, loft slab, corner slab etc

Beams – With or without openigs.(Shallow & deep beams)
Columns – (Rectangular,l-shape,t-shape, circular,octagonal,cross shape etc)
Foundations.

Detailing for gravity loads is different from the lateral loads specially for the SEISMIC FORCES.

Apart from the detailing for the above there is a different detailing required for the Rehabilitation and strengthening of damaged structures.

We will now dwell on the DETAILING OF MEMBERS FOR THE GRAVITY AND SOME CODAL DETAILINGS AS PER IS CODE IS 13920 AND IS 4326 AS REQUIRED FOR SEISMIC FORCES.

Sunday, July 31, 2011

CIVIL ENGG FACTS...IN INDIA

 # Sardar Sarovar Dam being executed by the group is the third largest in the world for volume of chilled concrete to be placed -nearly 7 million cum.

# Indira Sagar a 1000 MW Power house is the second largest surface power house in the country.

# Nathpa Jhakri a 1500 MW Power House is the largest underground power house in India.

# Tehri Dam is the third tallest rock fill dam in the world, and the largest in Asia involving placement of over 25 million cum of all types of fill material.

# Baglihar Hydroelectric project involved construction of 30km of project road along with three bridges.

# Brahmaputra Guide Bund completed in a record time of 7 months.

# Baspa-II and Chamera-II projects involved continuous concrete shuttering for tunnel lining which is used for the first time in the country.

# Teesta V project has been provided with Jet Grouting curtain is being provided below the coffer dams for the first time in India.

# Alimineti Madhva Reddy Irrigation project is the longest underground face to face tunnel in the world.

Tuesday, June 14, 2011

DOT NET

Q>what is dot net?
dot net is a framework for software development.it is similar in nature to any other software development framework (J2EE etc ) in that it rovides a set of runtime containers,and a rich set of pre built functionality in the form of class libraries and APIs.
it consist of : common language run time,the framework classes, and ASP.NET

Q>how many languages .net is suporting now?
about 44 languages.
VB.NET
C#
COBOL AND PERL. etc

Q>how .net able to suort multiple languages?
a languages should comply with the common language runtime standard to become a .net language.
in .net ,code is complied to microsoft intermediate language(MSIL for short).this is called as managed code.this managed code is run in .net environment.so after compilation to this IL the language is not a barrier.A code call or use a function written in another language.

Q>HOw ASP.NET different from ASP?
scripting is seprated from the HTML,code is complied as DLL, these DLLs can be excuted on the server.

Q>what is smart navigation?
the cursor osition is maintained when the page gets refreshed due to the server side validationj and the page gets refreshed.

Q>what is view state?
the web is stateless,but in ASP.NET ,. the state of a page is maintained in the page itself automatically.
how?
the values are encrypted and saved in hidden controls. this is done automatically by the ASP.NET. this can be switched off/on for a single control.

Q>how do you validate the controls in an ASP.NET page?
using special  validation controls that are meant for this.we have range validator e mail validator.

Q>can the validation be done in the server side?or this can be done only in the client side?
client side is done by default. server side validation is also possible. we can switch off the client side and server side can be done.

Q>how to manage pagination in a page?
using pagination option in data grid control we haver to set the no of records for a page, ten it takes care of pagination by it self.

Q>what is ADO.NET and what is difference b/w ADO and ADO.NET?
ADO.NET is stateless mechainsm. i can treat the ADO.NET as a separate in memory database where in I can use relation ships b/w the tabelsand select insert and udate to the database.I can update the actual database as a batch.

Q>explain the life cycle of an ASP.NET page.?
following are the events occour during ASP.NET page life cycle:
1] Page_prelnit
2] Page_lnit
3] Page_lnitComlete
4] Page_PreLoad
5] Page_Load
6] Controls Events
7] Page_LoadComplete
8] Page_preRender
9] SaveViewState
10] Page_Render
11] Page_Unload
 among above events page_render is the only event which is raised by page.so we cant write code for this event.

how does the cookies work in asp.net?
we know Http ia an state less protocol which is required for interaction b/w clinet and server.
so ther is no need  to remember state of request raised by an web browser so that,
web server can recognize you have already previously visited or not.

there are two types of state management techniques:
client side state management
server side state management
using cookies comes under client side state management. in Http response we write cookie containing sessionld and other information with in it.

when a browser made a request to the web server the same cookie is sent to the server where server recognize the session id and get other information stored to it previously.


Monday, June 13, 2011

precise traversing

precise traversing is theodolite traversing using more refined instruments and devices for linear and angular measurements.more advanced techniques are also used in field work.the theodolite used are special instrument such as the watt's wild,or zeiss theodolite. the accuracy attainable is at least 1 min of arc. its optical features are also superior. micrometer and double reading are invariably incorporated into these instruments. permanent adjustment are checked and ensured. for linear measurement ,a steel tape and steel band may be used ,and it is supported above the ground. the necessary correction have to be applied with due care.
regarding methods/techniques, the method in within included angels are measured at all stations is refereed. however the bearing of at least one of the sides of the traverse has to be measured with great accuracy so that the traverse is correctly oriented with respect to the north. a closed traverse is usually preferred so that all the relevant checks can be applied and closure ensured.
precise traversing is invariably conducted only under favourable atmospheric conditions, so that errors due to natural causes are minimised. the angular error of closure should not exceed "15 min under root N"
where N is the no of angles in the traverse. the limit of linear error recommended is in 10000 and in any case not more than 1 in 5000. precise traversing is primarily used to survey important boundaries, properties limits in urban areas where land acquisition costs are high, and in the location of important roads and railways. it is used only when triangulation is difficult as in the case of thickly wooded areas.

Sunday, June 12, 2011

curve by rankine

r=30 meters
T1=17.32m
L=30 meters
curve length=31.41meters
chainage of B=30 meters b is intersection point
chainage of T1=12.68meters
initial sub chord=7.32 meters
2nd sub chord 20 meters
last one 4.09m
small delta=(1718.9/R)length of sub chord
l ===>deflection angle from tangent (small delta)
7.32 => 419min 24 sec=>6deg 59min 20 sec
20 =>1145min56sec=>19deg6min
4.09=>234min20sec=>3deg54min20sec
diagram rankine wala deflection angle k through jo solve krte hai.

curve by chain tape method

R=30 meter DEFLECTION ANGLE=60
T 1 =R TAN 30=17.32 METERS
L= 2R SIN 30=30 METERS
CURVE LENGTH=31.41METRS
mid ordinate k formulae se Oo nikalo
then
x=>Ox
2=>3.952
4=>3.7511
6=>3.413
8=>2.932
10=>2.303
12=.1.514
14=>.552
15=>0
ek curve ka diagram bna lena offset from the long chord k liye

Saturday, June 11, 2011

vertical angle

O .....p....... 0 0 0............0 0 ............0 0 0
+ve...L ......2 25 40. .....25 20 .........2 25 30..... 7DEGREE 37MINUTE 40SECONDS
-ve....M.......5 12 20......12 00 ........5 12 10

FACE RIGHT
....................0 0 0....... 0 0 ............o 0 0.
...................2 26 00...... 25 40 ........2 25 50 ...............7DEG 38 MINJ 50SEC
...................5 12 40 ........12 20 .......5 12 30
AVG VERTICAL ANGLE 7DEG 37MIN 50 SEC

horizontal angle

s.n. i.s. .sighted to..face left.vernier a.vernier b..total angle.repetition.mean hori
1.......o.......L........0 0 0...........0 0.......0 0 0
.........o.......M.....52 41 20.....41 20.....52 41 20.....1
2......o.......L ......0 0 0...........0 0 ........0 0 0...........................52 41 26.67
........o.......M.......158 04 40...04 40.......158 04 40....3

face right observation
1......o...L......0 0 0...... 0 0..... 0 0 0
........o..M.....52 41 20....41 20...52 41 20......1
2......o..L.....0 0 0......0 0.....0 0 0...................................52 41 26.67
........o..M...158 04 40....04 40 ........158 04 40 3
vcalues in form of
degree minute seconds
min seconds