transportation , railway, airport Flashcards
(48 cards)
1
Q
Tractive efforts by locomotivess
A
F = .0016W +.00008W.V +.0000006W.v^2 +W tan(θ) +.0004D°.W
2
Q
transition curve locus in railway
A
y = x^3 /R.L
3
Q
gradient provided in station yard
A
1/1000 min
1/400 max
4
Q
martins formula for max speed
A
V= 4.35* sqrt(R-67) V= 4.58 sqrt(R) for high speed track
5
Q
radius of railway curve defined in degree
A
1720 /D°
6
Q
Length of cross over of track
A
S= (D-G)N - G* sqrt(1+N^2) L = 4.G.N +S
7
Q
Defects in bitumin road
A
SURFACE DEFECTS
- fatty surface
- smooth surface
- streaking
- hungry surface
CRACKS
- hair line cracks
- alligator cracks (map cracking)
- longitudinal crack
- edge crack
- shrinkage crack
- reflection crack
DISINTEGRATION
- stripping
- ravelling
- pot hole
- edge breaking
- loss of aggrigades
DEFORMATIONS
- slippage
- rutting (longitudinal depression)
- shoving(movement within the layer = localized bulging )
- shallow depression (settlement of lower layers)
8
Q
CBR test
A
california bearing ratio
soil sample 150mm =dia , h= 127mm
standard sample results
at 2.5mm penetration =1370 kg (70kg/sq.cm)
at 5mm penetration =2055 kg (105kg/sq.cm)
9
Q
plate bearing test
A
applicable in rigid and flexible both pavements
std dia of plate = 75 cm
seating load = 320 kg
K= p/0.125
10
Q
material test acceptence limits for base course and surface course
abression, crushing and impact
A
test – base course– surface course
L.abression – 50% – 30%
crushing val. – 45% – 30%
agg impact – 40% – 30%
11
Q
soundness test key points
A
resistence of aggrigade to weathering action
<12% -sodium sulphtae
<18% - magnisium sulphate
12
Q
material test acceptence limits flackiness/elongation angularity water absorption stripping value
A
flackiness/elongation <15%
angularity 0-11
water absorption <0.6%
stripping value < 25%
13
Q
bitumin penetration test
A
100g needle applied for 5 sec
penetration = 1/10 th of grade
14
Q
type and grade of bitumin - their use
A
30/40 - high volume traffic
60-70 - high traffic in normal summer
emulsion - premix, surface dressing in cold weather, wet condition, maintenance work
15
Q
cut back -grades, uses
A
Cutback Bitumen is a type of bitumen which is obtained when viscosity of bitumen is reduced by volatile dilutent. It is generally used in colder regions.
Different types of cutback bitumen are:
(i) Rapid Curing Cutback (RC): In this, bitumen is fluxed with NAPTHA / GASOLINE.
(ii) Medium Curing Cutback (MC): In this, bitumen is fluxed with KEROSENE.
(iii) Slow Curing Cutback (SC): In this, bitumen is fluxed with high boiling point dilulent.
suffux 0,1,2,3,4 for viscosity
eg MC-0 (least viscous, medium curing)
RT1 lowest viscosity used for surface painting
RT4 may be used for premix macadam
RT5 for grouting
16
Q
Marshall mix design test specification
A
stability = 340 kg
flow val = 8-16 units
penetration = 3-5 mm
VFB = 75-85 %
17
Q
Group index formula
A
G.I = 0.2a +0.005ac +0.01bd
18
Q
effect of addition of lime to soil
A
PL increases
19
Q
type of road construction - binder content
A
bituminous macadam = 3-3.5%
dense bituminous mac = 4-4.5%
bitumin concrete = 4.5-6%
bitumin mastic = 8-15%
20
Q
objectives of origin and destination studies
A
- to judge the adequacy of existing route
- to plan transportation system and mass transit facilities
- to establish preferential routes including by-pass
- to locate expressways or major routes along desire lines
21
Q
methods of origin and destination studies
A
- road side interview
- licence plate method
- return post card method
- tag on car method
- home interview method
22
Q
construction steps of dense bitumen macadam
A
- preparation of existing layer = patching pot holes and made even, surface properly cleaned
- tack coat or prime coat = using sprayer or poring can
- premix preparation = heating + mixing
- placement
- rolling and finishing the paving mix = 8-10 tones of tandem roller, from edges to center, roller wheels are kept damp,
23
Q
intro and construction steps of built up spray grout
A
Built-up spray grout consists of two layers composite
construction of compacted crushed aggregates with application of bituminous binder after each layer for bonding and finished with key aggregates at the top
to provide a total compacted thickness of 75 mm.
This method is commonly used for strengthening of existing bituminous pavements. A suitable wearing course is invariably provided over this layer before opening to traffic.
- preparation of existing base= proper grading and prime coat
- tack coat = heated bitumen binder
- spreading first layer = coarse aggregates are spread and packed
- rolling = 8-10 tonne roller
- application of binder = bitumen layer uniformly spread
- spread of second layer = immediately after binder layer
- rolling
- second layer of binder
- application of key aggregates
- surface finish
- opening to traffic
24
Q
penetration grade bitumen
A
specified in terms of penetration value
eg 30/40, 80/100
in hot climates lower penetration grade bitumen is required
25
blown bitumen points
```
- blown/oxidised bitumen are produced by passing air through soft bitumen mixtures under controlled temp conditions
representation
eg Blown bitumen 85/25
85 = softening point
25 = penetration range
```
26
Emulsions of bitumin points
It is a condition in which bitumen is suspended in an aqueous medium. It is used for patch-up work. The biggest advantage of bitumen emulsion is that it can be used in rainy season also.
Different types of emulsions are:
(i) Rapid Setting (RS): It is used for surface painting.
(ii) Medium Setting (MS): It is used for premixing with coarse aggregate.
(iii) Slow Setting (SS): It is suitable for fine aggregate mixes.
27
Lane Distribution Factors
As per IRc 37 2018
single lane= 1 for all vehicles on both directions
2 lane = .5 of vehicles on both directions
4 lane = 0.4 of vehicles on both directions
Dual carrageway
2 lane = 0.75 for 1 way traffic
3lane = 0.6 for 1 way traffic
4 lane = 0.45 for 1 way traffic
28
different types of traffic survey conducted
different types of traffic survey conducted
(a) Traffic volume study
(b) Speed Studies
(i) Spot speed study
(ii) Speed and delay study
(c) Origin and destination survey
(d) Traffic flow characteristics
(e) Traffic capacity studies
(f) Parking studies
(g) Accident studies
29
Various purpose of O-D survey are following:
(i) To judge the adequacy of existing routes and to use in planning new network of roads.
(ii) To plan transportation and mass transit facility
(iii) To locate major routes along desire line.
(iv) To locate terminal and terminal planning facility.
(v) To locate new bridge as per traffic demand.
(vi) To locate intermediate stop of public transport.
(vii) To establish design standards of road.
30
various equipment's used in road construction
```
Earth Moving Equipment
Aggregate Spreaders
1. Truck-mounted spreader
2. Truck-propelled spreaders
3. Self-propelled spreader
Rollers :
1. Smooth-wheeled rollers
2. Pneumatic-tyred roller
3. Sheepfoot rollers
4. Grid rollers
5. Vibratory rollers
```
* Nuclear Gauge
* Road Brooms
* Sprayers or Binder Distributors
* Paver Finisher
31
Bitumin and tar difference
BITUMIN
1. Manufactured by fractional distillation of petroleum (In presence of air).
2. Soluble in CS and CCl4 .
3. More resistant to water.
4. Less temperature susceptibility.
5. Free carbon content is less.
TAR
1. Manufactured by destructive distillation coal and wood (In absence of air) of .
2. Soluble in toluene.
3. Less resistant to water.
4. More temperature susceptibility.
5. More free carbon content.
32
As per Greenshield’s model and Greenberg’s model,
```
C= K *Vf *[1- K/Kj] Greendshield model
C= K *Vf *ln[Kj/K] , ...(K= Kj/e)
```
33
Desirable characteristics of grouting are as follows
(i) Groutability : It expresses the ability of the grout to reach the desired location in soil mass. For this grout must possess sufficient fluidity.
(ii) Stability : It is the capacity of grout to remain in fluid state and does not segregate into its individual components.
(iii) Setting time : Early setting can cause difficulty in grout reaching its destination and late setting can lead to grout being washed away.
(iv) Permanence : It is the resistance of grout from being washed away from soil voids with time.
(vi) Toxicity : It should not be toxic.
34
Running Speed
Time Mean Speed
Space-mean Speed:
Running Speed: It is the average speed maintained by a vehicle over a particular stretch
of road, while the vehicle is in motion. This is obtained by dividing the distance covered by the time during which the vehicle is actually in motion.
Time Mean Speed: It represents the speed distribution of vehicles at a point on the roadway and it is average of instantaneous speeds of observed vehicles at the spot.
Space-mean Speed: If represents the average speed of vehicles in a certain road length at any time. This is obtained from the observed travel time of vehicles over a relatively long stretch of the road. (Harmonic mean speed)
35
equivalent radius of resisting section
In case of design of rigid pavements, considering the case of interior loading, the maximum bending moment occurs at the loaded area and acts radially in all directions.
With the load concentrated on a small area of the pavement,
the question arises as to what sectional area of the pavement is effective in resisting the bending moment. This effective sectional area radius is termed as equivalent radius of resisting section.
b = sqrt(1.6*a^2 + h^2) - 0.675h
36
Prime coat
Prime coat : Bituminous prime coat is the first application of a low viscosity liquid bituminous material over an existing porous or absorbent pavement surface like the WBM base course.
The main objective of priming is to plug in the capillary voids of the porous surface and to bond the loose mineral particles on the existing surface using a binder of low viscosity which can penetrate into the voids.
Generally MC and SC cutbacks are used.
The primed surface is allowed to cure for at-least 24 hours during which no traffic is allowed.
37
Green highways
Green highways : Green highways are those that are environmentally friendly, pollution-free, aesthetically pleasing and ecologically sustainable.
Some of the guidelines for developing green highways are:
• promote growth of native species of trees and vegetation and control population of invasive species.
• protect hydrology and restore natural drainage paths.
• promote porous pavements for better management of storm water.
• promote wildlife corridors and passages in areas identified through wildlife conservation plans.
• use recycled materials.
• reduce energy consumption in building roads.
• promote water-harvesting.
38
National Highways Development Project (NHDP)
National Highways Development Project (NHDP) : National Highways Authority of India (NHAI) took up the National Highways Development Project (NHDP) by the year 2000, in different phases. Phase-I of NHDP is called the ‘Golden Quadrilateral’ of total length 5846 km connecting the four major metropolitan cities.
The four sides of the quadrilateral are,
(i) Delhi-Mumbai,
(ii) Mumbai-Chennai (via Bangalore),
(iii) Chennai-Kolkata and
(iv) KolkataDelhi.
This project was started in December 2000 and was planned to be completed in six years.
Phase-II of NHDP consists of , (a) North-South corridor
connecting Srinagar to Kanyakumari and (b) East-West corridor connecting Silchar to Porbandar, of total length 7300 km.
Additional spurs connecting some of the major industrial cities and ports were also taken up along with these
projects.
Further development of selected stretches of national highways was planned in phases III, IV and V. Development of expressways was planned as phase VI
and improvements of urban road networks in phase VII.
39
P/W or impact factor for skidding in super elevations
P/W = V^2 /2g = (e+f)/(1-ef)
40
Va and Vb in overtaking sight distance calculation, if not mentioned
```
Va = Vc = 80 kmph (design speed)
Vb = Va -16kmph
```
41
Wastergaard’s stress equations for rigid pavement
Wastergaard’s stress equations for rigid pavement
if a> 1.724 h :
b= a
else
b = √(1.6〖a〗^2+h^2 ) -0.675h and
l =[(E h^3)/(12K.(1-μ^2))]^0.25
Interior
Sc = [4*log_10〖l/b〗 +1.069]×(0.316 P)/h^2
Edge
Se = [4*log_10〖l/b〗 +0.359]×(0.572 P)/h^2
Corner
Sc = [1-〖(a√2)/l〗^0.6 ]×(3 P)/h^2
42
maximum spacing of slabs for expansion joint
140m
| slab is allowed to expand to 1/2 of expansion gaap
43
Write down the construction steps for Water Bound Macadam road.
The construction of WBM roads may be divided into following steps:
(i) Preparation of foundation for receiving the WBM course: The foundation layer i.e.
subgrade, subbase or base course is prepared to required grade and camber. On existing road surfaces, the depressions and pot holes are filled and corrugations are removed by scarifying and reshaping the surface to the required grade and camber
(ii) Provision of Lateral Confinement: It may be done by constructing the shoulders to
advance to a thickness equal to that of compacted WBM layer.
(iii) Spreading of Coarse Aggregate: The coarse aggregates are spread uniformly to proper profile to even thickness upon the prepared foundation.
(iv) Rolling: Rolling is started from the edges and then gradually shifted towards the centreline of the road.
(v) Application of screenings: After the coarse aggregates are rolled adequately, the dry screenings are applied gradually over the surface to fill the interstices in three or more applications.
(vi) Sprinkling and Grouting: After screeching, the surface is sprinkled with water, swept and rolled.
(vii)Application of Binding Material
(viii) Setting and Drying
44
Difference between WMM and WBM
Wet Mix Macadam (WMM)
-Stone aggregates are comparatively smaller in size (4.75-20 mm)
-Stone aggregates and binding materials are
premixed in a batching plant
-Prepared by stone aggregates and binders
Water is premixed
Water Bound Macadam (WBM)
- Stone aggregate are larger in size (45-90 mm)
- Stone aggregates, screening material and binders are overlaid one after another
- Prepared by stone aggregate, screening and binding material
- Water is sprinkled on dry material
45
The limitation of the plate load test are:
Limitation of the plate load test
The plate load test has the following limitations:
1. Size effect: The results of the plate load test reflect the strength and the settlement characteristics
of the soil within the presure bulbs. As the pressure bulb depends upon the size of the loaded area,
it is much depper for the actual foundation as compared to that of the plate Figure. The plate load
test does not turly represent the actual conditions if the soil is not homogenous and isotropic to
a large depth.
2. Scale effect: The ultimate bearing capacity of saturated clays is independent of the size of the
plate but for cohesionless soils, it increases with the size of the plate. To reduce scale effect, it
is desirable to repeat the plate load test with plates of two or three different sizes and extraplate
the bearing capacity for the actual foundation and take the average of the values obtained.
3. Time effect: A plate load test is essentially a test of short duration. For clayey soils, it does not
give the ultimate settlement. The load settlement curve is not truly representative.
Interpretation of failure load: The failure load is not well-defined, except in the case of a general
shear failure. An error of personal interpretation may be involved in other types of failure.
4. Reaction load: It is not practicable to provide a reaction of more than 250kN. hence, the test on
a plate of size larger than 0.6m width is difficult.
5. Water table: The level of the water table affects the bearing capacity of the sandy soils. If the water
table is above the level of the footing, it has to be lowered by pumping before placing the plate.
The test should be performed at the water table level if it is within about 1m below the footing
46
Housel’s method of plate load size relation
Housel’s method of plate load size relation
| Q = Area.m + P.n
47
Runway corrections
- only elevation correction applied on landing runway length, all other are for take off only
- elevation corr = 7% for every 300m increase in height above MSL
-ART = 2/3.Tm + 1/3.Tmax
dT = 15 - 0.0065.h
-temp corr = 1% increased for every (ART-dT)
- temp correction + elevation correction < 35%
- grade correction =20% for every 1% grade
48
tests on bitumin
Penetration Test: 100g needle 5 sec, at 27 C temp
Ductility Test: 10x10mm briquette @ 50mm/min
Float test:
Viscosity test: 10mm orifice , 50 cc bitumin
solubility test:
specific gravity test:
softning point test:
fire and flash point test:
spot test
loss of heating test
water content test
