In bridge widening projects, the method of stitching is normally employed for connecting existing deck to the new deck. What are the problems associated with this method in terms of shrinkage of concrete?

In bridge widening projects, the method of stitching is normally employed for connecting existing deck to the new deck. What are the problems associated with this method in terms of shrinkage of concrete?

In the method of stitching, it is a normal practice to construct the widening part of the bridge at first and let it stay undisturbed for several months. After that, concreting will then be carried out for the stitch between the existing deck and the new deck. In this way, the dead load of the widened part of bridge is supported by itself and loads arising from the newly constructed deck will not be transferred to the existing deck which is not designed to take up these extra loads.

One of the main concerns is the effect of stress induced by shrinkage of newly widened part of the bridge on the existing bridge. To address this problem, the widened part of the bridge is constructed a period of time (say 6-9 months) prior to stitching to the existing bridge so that shrinkage of the new bridge will take place within this period and the effect of shrinkage stress exerted on the new bridge is minimized.

Traffic vibration on the existing bridge causes adverse effect to the freshly placed stitches. To solve this problem, rapid hardening cement is used for the stitching concrete so as to shorten the time of setting of concrete. Moreover, the stitching work is designed to be carried out at nights of least traffic (Saturday night) and the existing bridge may even be closed for several hours (e.g. 6 hours) to let the stitching works to left undisturbed.

Sometimes, longitudinal joints are used in connecting new bridge segments to existing bridges. The main problem associated with this design is the safety concern of vehicles. The change of frictional coefficients of bridge deck and longitudinal joints when vehicles change traffic lanes is very dangerous to the vehicles. Moreover, maintenance of longitudinal joints in bridges is quite difficult.   

Weight of steel bars per meter – Weight of steel bars formula

Diameter of bars in millimeter	Weight of bars in kilogram
6 mm	0.22 kg/meter
10 mm	0.62 kg/meter
12 mm	0.89 kg/meter
16 mm	1.58 kg/meter
20 mm	2.469 kg/meter
25 mm	3.858 kg/meter

Weight of steel bars formula

To calculate weight of steel bars, there is a formula used to calculate weight.

W=(D^2 x L)/162

what is Rough cost estimate

what is Rough cost estimate

Rough cost estimate is also called approximate estimate. Because in approximate estimate we can find out the estimation of building an approximatly.This is an inexact estimate to find out a rough cost in a short time which enables the authority concerned to consider the financial aspect of the scheme, for according sanction to the same. Such an estimate is framed after knowing the rate of similar works and from practical knowledge in various ways for various types of works such as.

Approximate estimate can find out with the help of Plinth area or square-meter , Approximate quantities with bill,Cubic rate or cubic meter and The cost of materials and labor. so we can find out the approximate or rough cost estimate with these method which i have discussed. so the approximate estimate is generally used for rough cost estimate, which are just used for simple project. but remember this estimate is not accurate in construction works, because this is just approximate quantity.

Types of Estimate

Types of Estimate

• Original Estimate
• Repair Estimate

Types of Original Estimate

1. Rough Cost Estimate
2. Detailed Estimate

Types Of Rough Cost Estimate

• Per Unit Number
• Plinth Area Basis
• Cube Rate Estimate 
• Per Unit Length of Wall
• Per Unit Length of Road & Heighway
• Per Unit Length of Irrigation Channel
• Per Unit Length of Railway Track
• Per Litre For Over Head Water Tanks

1. Detailed Estimate

Detailed Estimate take every quantity of every item and multiply with unit of rate..
\
for example…

• excavation.. 
• Brick Masonary.. 
• R.c.c. 
• Plaster
• Steel 
• Flooring
• Tile and fishing work

First we take measurement and them prepared abstract of Cost.

   2.  Types Of Repair Estimate

• Annual Repair Estimate
• Quadrennial Repair Estimate
• Special Repair Estimate

What is Quantity Surveying/ Estimation

Quantity Surveying/ Estimating

An art to collect data about material and cost required for a project is called
QUANTITY SURVEYING/ESTIMATING.
The Process of cost estimating is working out how much a building or other
construction will cost to make. The cost are usually divided into material and labour
cost..

TENDERING is the process of making a priced offer to construct the building. This is a
legally enforcable offer made within the conditions of the tender documention.
Necessary data for preparing an estimate of project are

1. Drawings
2. Specifications 
3. Rates.

Types of Estimate
A. Original Estimate
B. Repair Estimate

RATE ANALYSIS sandwich panel Sheet 50mm mm thick ( Pre painted )

RATE ANALYSIS
	Job Description
Providing , installation of M.S sandwich panel Sheet 50mm mm thick ( Pre painted ) over M.S frame structure  using hex washer head self tapping & drilling screws and over laping G.I Sheet 24-SWG at corners painted with matching colour  i/c carrage of material from lahore to Gojra at site of work through Cantainer/troller , charges of uplifting through crane at 40' height for installation, cost of all other  materials ,  labour  etc complete in all respects as per drawing and design  as approved and advised by the Consultant / Engineer Incharge.
(1st BI-ANNUAL-2017 , 01.01.2017 TO 30.06.2017)
Unit:	P. Sft				Take for analysis= 37.5' x 45'=1687.5 Sft
S. No.	Description					Unit	Quantity	Rate	Amount
A	Materials
1	M.S Sandwich panel sheet full width 38ft.
	Top                    38' x 37.5'		=	1425	Sft
	Front                    37.5' x 2.66'		=	99.75	Sft
	Back                    37.5' x 5.66'		=	212.25	Sft
	Add wastage 5 %			86.85	Sft
		Total	=	1823.85	Sft	Sft	1,823.85	580.00	1,057,833
	G.I Sheet 24 SWG
	Front                    37.5' x 1'		=	37.5	Sft
	Back                    37.5' x 1'		=	37.5	Sft
	Add wastage 5 %			3.75	Sft
		Total	=	78.75	Sft
	78.75 Sft @ 1.156 Lbs/Sft		=	41.33	Kgs	Kg	41.33	100.00	4,133
2	hex washer head self tapping & drilling screws
	Top and sides @ 3' c/c			247	Nos
	Add wastage 10 %			25.00	Nos
		Total	=	272.00	Nos	Nos	272.00	35.00	9,520
3	Steel cutting disc					Each	5.00	480.00	2,400
4	Electricity					Unit	75.00	20.00	1,500
	Total Amount ( A ):								1,075,386
B	Carriage and hire charges
2	38' Length roof sheet panel on troller container i/c loading & Unloading					Each	33%	30,000.00	10,000
4	Drill machine for 3 days @ 300 / day					Day	3.00	300	900
6	Crane for uplifting the full length sheet panels and placing them at proper place upto 40' height.					Day	1.00	30000	30,000
	Total Amount ( B ):								40,900
C	Labour
(a)	Labour required  Fixing M.S Sandwich Panel Sheet.
1	Technician
	1 Nos for 3 days					Days	3.00	2,800	8,400
2	Skilled Cooly ( LB-024)
	4 Nos for 3 days					Days	12.00	608	7,296
	Add sundries 10%								1,569.6
	Total Amount ( C ):								17,266
	Total Amount (A+B+ C ):								1,133,552
	Contractor profit , taxes , site expenses and  over head 20%								226,710.3
	Grand Total Amount:								1,360,262
	Rate Per Sft   =	1360262/1687.5							806.08
							Say Rs	806	P/Sft

RATE ANALYSIS of 60HP centrifugal pump

RATE ANALYSIS
	Job Description
Providing and installation of centrifugal pump for Sprinklers system Specially made on order from PECO Pakistan , of PCO 100-L  with electric motor (PECO)  60HP , 400V, 50HZ, 2900 RPM, 3Phase,fitted on R.C.C plate form using special nut bolts 12" long i/c electric controll panel with main breaker , Phase failure, Amp Meter, Volt meter, selector Switch ,Push Button ,internal wiring etc Complete in all respects  as approved by the consultant/ Engineer Incharge.
Unit:	P. Each
S. No.	Description					Unit	Quantity	Rate	Amount
A	Materials
1	Cost of  centrifugal pump Specially made on order from PECO Pakistan , of  PCO 100-L with electric motor (PECO)  60HP , 400V, 50HZ, 2900 RPM, 3Phase (Quotation Atteched) Including GST with  controll panel with main breaker , Phase failure, Amp Meter, Volt meter, selector Switch ,Push Button ,internal wiring etc Complete					Each	1.00	625000	625,000
2	Control box of M.S Sheet 16-SWG openable with wiring.					Each	1.00	10000	10,000
3	Nut Bolts 12" Long including rubber bearing pad					Nos	4.00	375	1,500
4	Carriage of  Pump from PECO factory Lahore to Gojra site.					Job	1.00	L.S	5,000
5	installation Charges.					Job	1.00	L.S	5,000
6	Installation of Control box, starter,connectioning and testing charges					Job	1.00	L.S	10,000
	Total Amount:								656,500
	Contractor profit , taxes , site expenses and  over head 20%								131,300.0
	Grand Total Amount:								787,800
					Say Rs		787,800		P/Each

RATE ANALYSIS of HDPE Plan Bend 90 degree

	RATE ANALYSIS
		Job Description
	Providing /Fixing High Density Poly Ethylene ( HDPE ) Plan Bend 110mm dia (Dadex / Beta / BBJ / or any equivalent)   i/c polyfusion joint, solvent solution as approved by the consultant and Engineer Incharge  complete in all respect.
	Unit:	Each		Take for Analysis = 1 No
	S. No.	Description	Unit	Quantity	Rate	Amount
	A	Materials
	1	Elbow 90* 110mm ( Rate List attached ) With wastage 10 %	No	1.10	1200	1,320
	3	Electricity for Joints Machine( 2 Joints )	Unit	5.00	20.00	100.00
		Total Amount ( A )				1,420.00
	B	Carriage and hire charges
	1	Carriage of matieral at site	Each	1 /15	900	60.00
		Total Amount ( B )				60.00
	C	Labour
	1	For Polyfusion welded joint with machine i/c Labour  ( as per Market Rate)	Each	2.00	700	1,400.00
		Total Amount ( C )				1,400.00
		Total Amount ( A + B + C ):				2,880.00
		Contractor profit , taxes , site expenses  and over head  20%				576.00
		Grand Total Amount:				3,456.00
		Rate For Each.:				3,456.00
		Say:			3,456	Each

Irrigation canals are generally aligned along

Irrigation canals are generally aligned along

A. ridge line B. contour line C. valley line D. straight line. Answer: Option A

Units of Measurement

Units of measurement used in past and present surveys are

For construction work: feet, inches, fractions of inches (m, mm)
For most surveys: feet, tenths, hundredths, thousandths (m, mm)
For National Geodetic Survey (NGS) control surveys: meters, 0.1, 0.01, 0.001 m

The most-used equivalents are
1 meter=39.37 in =3.2808 ft
1 rod =1 pole=1 perch=16.5ft(5.029 m)
1 engineer’s chain =100 ft =100 links (30.48 m)
1 Gunter’s chain= 66 ft (20.11 m) =100
Gunter’s links(lk)=4 rods=0.020 km

1 acre=100,000 sq (Gunter’s) links=43,560ft²= 160 rods²=10 sq (Gunter’s) chains=4046.87m²=0.4047 ha

1 rood=1011.5 m²=40 rods²

1 ha= 10,000 m²=107,639.10 ft²=2.471 acres

1 arpent=about 0.85 acre, or length of side of 1 square arpent (varies) (about 3439.1 m²)

1 statute mi=5280 ft=1609.35 m

1 mi²=640 acres (258.94 ha)
1 nautical mi (U.S.)= 6080.27 ft= 1853.248 m

1 fathom=6 ft (1.829 m)

1 cubit=18 in (0.457 m)

1 degree=0.01745 rad=60 min =3600 s
sin 1 =0.01745241
1 rad = 57.30 degree

What are the Characteristics of Contours?

Contours show distinct characteristic features of the terrain as follows:

i) All points on a contour line are of the same elevation.

ii) No two contour lines can meet or cross each other except in the rare case of an overhanging vertical cliff or wall
iii) Closely spaced contour lines indicate steep slope

iv) Widely spaced contour lines indicate gentle slope

v) Equally spaced contour lines indicate uniform slope

vi) Closed contour lines with higher elevation towards the centre indicate hills

vii) Closed contour lines with reducing levels towards the centre indicate pond or other depression.

viii) Contour lines of ridge show higher elevation within the loop of the contours. Contour lines cross ridge at right angles.

ix) Contour lines of valley show reducing elevation within the loop of the contours. Contour lines cross valley at right angles.

x) All contour lines must close either within the map boundary or outside.

Explain Terms Used in Contouring

Define Contour Line
A Contour line is an imaginary outline of the terrain obtained by joining its points of equal elevation. In our example of the cone, each circle is a contour line joining points of same level.

Define Contour Interval (CI)
Contour interval is the difference between the levels of consecutive contour lines on a map. The contour interval is a constant in a given map. In our example, the contour interval is 1m.

Define Horizontal Equivalent (HE)
Horizontal equivalent is the horizontal distance between two consecutive contour lines measured to the scale of the map.

Gradient
Gradient represents the ascending or descending slope of the terrain between two consecutive contour lines. The slope or gradient is usually stated in the format 1 in S, where 1 represents the vertical component of the slope and S its corresponding horizontal component measured in the same unit.

The gradient between two consecutive contour lines can also be expressed in terms of Tan Q(theta) as follows:
Tan Q (theta) = CI / HE … both measured in the same unit.

ESTIMATION METHODS OF BUILDING WORKS

The estimation of building quantities like earth work, foundation concrete, brickwork in plinth and super structure etc., can be workout by any of following two methods:

a) Long wall – short wall method

b) Centre line method.

c) Partly centre line and short wall method.

a) Long wall-short wall method:

In this method, the wall along the length of room is considered to be long wall while the wall perpendicular to long wall is said to be short wall. To get the length of long wall or short wall, calculate first the centre line lengths of individual walls. Then the length of long wall, (out to out) may be calculated after adding half breadth at each end to its centre line length. Thus the length of short wall measured into in and may be found by deducting half breadth from its centre line length at each end. The length of long wall usually decreases from earth work to brick work in super structure while the short wall increases. These lengths are multiplied by breadth and depth to get quantities.

b) Centre line method:

This method is suitable for walls of similar cross sections. Here the total centre line length is multiplied by breadth and depth of respective item to get the total quantity at a time. When cross walls or partitions or verandah walls join with main wall, the centre line length gets reduced by half of breadth for each junction. Such junction or joints are studied carefully while calculating total centre line length. The estimates prepared by this method are most accurate and quick.

c) Partly centre line and partly cross wall method:

This method is adopted when external (i.e., around the building) wall is of one thickness and the internal walls having different thicknesses. In such cases, centre line method is applied to external walls and long wall-short wall method is used to internal walls. This method suits for different thicknesses walls and different level of foundations. Because of this reason, all Engineering departments are practicing this method.