1. SAFETY MEASURES IN EXCAVATIONMost of the new civil engineering structures and buildings will require excavations to be made for their foundations. It is also absolutely essential that before the surface excavation is commenced on a site the position of all underground utilities and services such as water supply pipelines, sewers, gas-pipelines, electric cables, telephone cables etc. should be verified to avoid accidents and hazards to workers and damage to utilities and services. The gas and water pipelines should be shut off and the electric cables should be disconnected.

1.1. HAZARDS IN SURFACE EXCAVATION: a) EARTH COLLAPSE b) PUNCTURING ELECTRICAL CABLES/WATER LINES c) POISONOUS GASES1.2. SAFETY MEASURES IN SURFACE EXCAVATION IN EARTH, SOIL,

CLAY, SAND ETCIt is essential that before the excavation in earth, soil, clay, sand etc., is commenced, an engineer or a competent person has ascertained the type, nature and properties, including ground water table of the strata of the entire area of the excavation. If the borehole data are available it should be analysed carefully to decide the suitable methods of excavation viz., cutting back the sides of the excavation to a safe slope, or adopting vertical sides supported by timbering or sheeting, either partial or close-sheet piling etc. This will help in taking proper and adequate safety measures.

1.3. ANGLE OF REPOSE FOR VARIOUS SOILS:ANGLE OF REPOSE: Measured from the horizontal, it is the maximum angle of plane which coarse particles in the material begin to fall under the affluence of gravity. Also known as critical slope.

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Slope ratio Angle ofHori : Veri Repose

inDegrees

Ashes : Coal 1.0 : 1 45Cinders : Coal 1.0 : 1 45Clay : Dry 1.3 : 1 38

: Damp 2 .0 : 2 27Coal : Broken 1.4 : 1 36 Earth : Dry 1.3 : 1 38

: Damp 2 .0 : 1 27Gravel : Round 1.7 : 1 30

: Angular 1.3 : 1 38

Rock : Broken : Soft 1.5 : 1 34 : Hard 1.3 : 1 38

Rock : Weathered : Residual 1.5 : 1 34: Weathered rock

In all excavations safe means of access and egress should be provided for the workers carrying out the excavations. As far as practicable, the excavations should be kept free from water, which will provide safe working conditions.The side slopes of the excavations wherever they are adopted should be designed properly and should be stable under all conditions. No materials should be stacked near the edge of any excavation. No load, plant or equipment should be placed or moved near the edge of any excavation where it is likely to cause a collapse of the side of the excavation and thereby endanger any person.The workers in a narrow trench are exposed to hazards from falling soil or rock, from the dislodgement of trench supports, and from vehicles, plant and construction materials falling into an unguarded excavation.In deeper excavations (more than 1.50 M. deep) where there is unstable or moving ground, the excavation should be made safe by shoring or timbering or sheet pilling. All struts, brace and waling in excavations should be adequately secured so as to prevent their accidental displacement. Deep trenches and pits should be provided with adequate ladder which should extend atleast one meter

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above ground level. The ladders should be firmly fixed in position. When buckets of materials or heavy materials are lowered, precautions should be taken to prevent injuries to the worker in the trench.Excavations for basement type of structures are normally sited in urban areas where there is need to safeguard existing building. Large-scale excavation for highways, dams etc., do not usually involve hazards from instability of slopes. 1

Accidents, which do take place in this type of work, are usually confined to those in which the workers are injured by the construction equipment and transport vehicles/dumpers deployed in the works. For safety of the workers in this type of excavation vehicle/dumpers should be fitted with warning lights and sirens; there should be uniform system of signaling; enforcement of rules to drivers and plant operators and adequate floor lighting for night work.

1.4. SAFETY MEASURES IN ROCK EXCAVATION:

Excavation in rock is required for the foundations of civil engineering structures such as dams, bridges etc; quarrying of rock for stones and for tunneling and shaft sinking.Excavation in soft rock or bedded and fissured rock can be done by hand tools if the quantity of the excavation is small; otherwise, it is to be done by pneumatic tools or excavating equipments. However, the excavation in sound and solid rock is normally done by pneumatic drilling and blasting of the rock by suitable explosives.Excavation of solid and sound rock for foundation which requires the use of explosives should be done by an experienced engineer as it is particularly important to control the throw of blasted material and also the vibration level which is achieved by means of short delay multiple row blasting with small diameter of holes and appropriate charges of explosives depending on the nature and type of the rock and size of the fragmentation required.Specific safety measures required for the excavation of rock by pneumatic drilling and blasting by explosives are detailed here as under.Loose or disintegrated rock is removed by hand tools or pneumatic jackhammers. Holes are drilled by pneumatic hand held drills to a specific pattern. Drillers should were protective hand-gloves and gumboots and helmets if they are drilling in a pit where there is a danger of rock fall.

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The explosives and detonators are used for blasting the rock. The storage, transport and handling of the explosives should be laid down in explosives rule, 1940. Explosives are transported on roads .in a specially built vehicle called as explosive van.Explosives and detonators are to be carried in separate trips. The explosives and detonators are stored in a specially approved magazines. The explosives and detonators are removed by the authorised blasting foreman only.When drilling of all the holes in a specific pattern is completed and checked for the correct required depth of the holes, the drilling crew is withdrawn from the site with all the drilling equipment and accessories. The blasting foreman will check all the holes to be blasted before he brings the explosives and detonators to the area to be blasted. No smoking or open flare shall be allowed in the explosive loading area.The explosive cartridges are prepared with the detonators and are inserted into the drilled holes. The cartridges are not forced into the holes. The holes are filled with clay and sand sticks at the top, tamping of the cartridges in the hole is done by a wooden stick gently. Care should be taken so that the detonators wires are not damaged or pulled out. Continuity of the entire circuit is checked by a blasting circuit tester and the resistance of the circuit also measured. The lead wire of the circuit are connected to the exploder. The firing switches of the exploder must be kept in "open" position and locked, and the keys are to be kept with the blasting foreman only who is responsible for the firing of the shots. The surplus explosives and detonators are returned to the magazines. The blasting foreman then sounds a warning siren so that the persons move out of danger area to a safe distance and nobody is allowed to enter the blasting area. Then he fires shots by closing the switch of the exploder.After the explosive fumes are dispersed the blasting foreman returns to the firing area and checks if there is any misfire. If there is a misfire, the unblasted hole it is flooded with water. The blasting foreman arranges very carefully to drill a new hole parallel to the unexploded hole, charges it with suitable charge of explosive and blasts the new hole by observing the same precautions stated before. If there is no misfire then he signals "all clear" sign so that the work of removing of the blasting materials can commence

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4.0. SAFETY MEASURES IN SHAFT SINKING EXCAVATION, PILING & OTHER RELATED WORKS.4.1. SHAFT SINKING

The shaft which is not sunk through solid rock should be cased, lined or otherwise made safe. As far as practicable ,workers employed in sinking shafts should be protected against the falls of objects. Workers employed on sinking shafts should be provided with staging or cradles from which they can work safely.As soon as practicable, the shaft top should be protected by adequate fencing or guard rails and toe boards and gates. When a shaft is being sunk through water bearing strata, adequate means of escape from the bottom should be provided. All shafts should have ladder way from the surface to the workings, in additions to any mechanical means of ingress and egress. Winches at shaft tops should be so installed that the bucket can be attached and detached safely. Top of the shaft should be adequately protected against inrushes of water. All shafts over 30M in depth should have an adequate headframe .All landings in shafts should be provided with gates that effectively close the opening to a height of atleast 2.00M.

4.2. EXCAVATION

a) Sides of all excavations must be sloped to a safe angle not steeper than the angle of repose of the particular soil. Angle of repose for various soils are given in Table 2. If it is not possible to give a proper slope, the sides of excavation, where there is a danger of fall or dislodgement of earth or any material shall be securely supported by timber or any other type of shoring. Where the excavation is being carried out with ' Poclain' step down procedure should be followed.

b) No excavation or earth work below the foundation level of any adjoining building in an existing plant/factory shall be taken up unless adequate steps are taken to prevent damage to the existing structure.

c) Every accessible part of an excavation, pit or opening in the ground into which there is a danger of person falling shall be suitably fenced with a barrier upto a height of three feet as close to the edge the excavation as practicable.

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d) No material or load shall be placed or stacked near the edge of the 85 excavation or opening in the ground. The excavated material shall not be placed within 5 Ft of the trench or half the depth of the trench whichever is more.

e) Cutting shall be done from top to bottom. No undercutting of side of excavation shall be allowed.

f) All narrow trenches 4 feet or more deep shall at all times be supplied with at least one ladder for each height of in length or fraction there of. Ladder should be extended from bottom of the trench to at least 3 feet., above the surface of the ground

g) The side of trenches which are 5 feet. or more in depth shall be stepped back to give suitable slope or securely held by planking, strutting and bracing, so as to avoid the danger of side collapse.

h) Before starting any excavation of any description in the existing plant /factory area premises, permission in writing (WORK PERMIT) must be obtained from Electrical Division, Civil Engineering and Design Department of the clients to avoid any damage to the underground electric cables or pipelines.

i) Any excavation or ditch more than 5 feet deep must be properly shored if angle of repose is not given, before any worker is permitted to work in it. All timber and planks used there in shall be inspected by a competent person. Undercutting of banks shall not be permitted. Erosion of soil over excavated pits, trenches must be prevented from running water by dewatering pumps, etc.

j) Excavation inside any part of the existing plant/factory must be properly fenced and marked with suitable warning boards or lights at all times. This also applies to any trench or drain which has its cover removed.

k) No loose material or load shall be placed or stacked near the edge of any excavation so as to endanger the lives of person working below.

l) When it is necessary to block off any road inside the existing plant or factory premises, proper road-barrier must always be used and existing rules of clients to be followed.

m) Pick and shovel people working in excavations should be kept far enough apart to prevent injury to one another.

n) All workmen working inside the pit shall necessarily wear Safety helmets and those who are working in the slopes or benches of the pit shall use safety belt also.

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4.3. SOIL TESTING, PILING AND OTHER RELATED WORKS :Following safety measures are observed in Soil Testing, Piling And Other Related Works :

a) The wire ropes used should be of sufficient dia and strength to take the impact lead of chisel casing and sludge pump. A regular inspection of wire ropes should be carried out at frequent intervals.

b) Wire ropes with broken strands should not be used. A register showing history of wire ropes be maintained giving information on the inspections, repair carried out.

c) Suitable attachments be made in the pump and chisel so that these may safely be recovered without sending any person inside the bore holes whenever necessary.

d) If a person is to be sent inside any confined space i.e. sewer line, tunnel, well etc. the following steps be taken.

i) A certificate, in writing has to be given by a competent person, based on a test carried out by himself that the space is free from dangerous fumes and fit to enter and/or

ii) The worker is wearing suitable bearing apparatus and belt securely attached to a rope the free end of which is held by a person standing outside the confined space.

e) No person shall be permitted to enter any boiler furnace, boiler flue chamber, tank vat, pipe or other confined space for the purpose of working or making any examination there in until it has been sufficiently cooled by ventilation or otherwise made safe for persons to enter.

f) In case there is no sufficient projection of mental casing above ground level, adequate fencing should be provided in order to avoid fall of persons inside.

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3. 0. SAFETY MEASURES FOR UP GRADING OF EXISTING ROAD WORKS.

Road maintenance poses a greater variety of safety problem than do most other fields of heavy constructional engineering, since the hazards normally associated with such operation are multiplied several times over. The process of surfacing or resurfacing a roadway involving as it does the use of heavy mobile equipment and the close proximity of moving streams of road traffic, calls for a high degree of safety consciousness on the part of the work party as a whole.

3.1. HAZARDS

Vehicle – Trucks reversing to unload asphalt or crushed stone are particular source of danger, since the driver’s vision is partially obscured and his attention is concentrated on placing his truck in the most advantageous position. The works crew should be repeatedly warned highlighting that a backing maneuver is in progress. Personnel should remain clear of raised truck dump bodies to prevent injury in the event of hydraulic lift failure. When empty, the tailgate of the dump body becomes a pinch point and caution is called for on the part of the workers assigned to clean the dump bed.

For large compacting equipment (smooth wheeled, pneumatic tyred or sheep’s foot rollers), hazard pose because of its size and the frequent inability of the operator to see adequately while braking. Brakes and steering should be in a good state of repair at all times. (Only road rollers provided with a stopping device Operators must exercise great care when rolling surfaces in the midst of a work party: one man should be given the responsibility of making sure the area to be rolled is clear of personnel.

Small vibrating plate compactors used on small areas expose workers to the hazards of vibration and noise guards must be provided.

All workers engaged on works with hot asphalt should wear good clothing covering the entire body, shoes with sound soles and heavy socks.

The asphalt distributor used to apply the prime and tack coats for new surfaces should be kept clean and free of asphalt residue, burners should be examined for freedom from obstructions and the circulating system should be checked for proper circulation and for leaks. Highly volatile fluids such as petrol should not be used for cleaning purposes and open flames should be kept away from distributor spray bars. Rags or waste material capable of spontaneous ignition should never be allowed to collect on the distributor. The

exhaust system of the truck motor should be vented away from the tank and checked frequently for holes and leaks.

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Only persons who are thoroughly familiar with asphalt kettle and the characteristics of asphalt should be chosen a s kettle attendants. Gloves should be worn when handling the hand spray attachment. Kettles should be set securely and kept clean. Special attention being given to exhaust stacks. Loose connection should be tightened and worn hoses replaced immediately.Bituminous fumes: During asphalting in open air, fumes and dust concentrations in the brathing zone of the worker are as a rule, relatively low. They can, however, reach significant levels during liquid asphalt pouring. To minimise the risk of polycyclic aromatic hydrocarbons, the use of coal tar base asphalt should be prohibited. In the central mixing plant short term peak concentrations of amines can provoke irritations of conjunctivae and respiratory mucous. Asphalt mixers should be provided with efficient fume and dust control devices and in case of high concentrations of fumes and dust respiratory protection should be available.Power Cables: Whenever operations necessitate the use of equipment as booms, cranes, excavation and digging machines etc there may be accidental contact with utility services supplies unless all employees maintain a constant awareness of the proximity of electrical lines, (both overhead and underground), Underground waterpipe and so on. Before work is started in the vicinity of these, the respective company should be advised as they may be able to reduce or remove the hazards. Arrangement should be made far enough in advance to prevent delay.

3.2. SAFETY MEASURES

The responsibility of the safety officer is to ensure the safety of the general public motorist, pedestrian, resident, the workers and the construction equipment. Priorities should be assigned to specific hazardous areas as determined by location, length of job, night-time requirements etc. the type of work area protection required being determined by the nature and density of the traffic. For all practical purposes, drilling or boring across a roadway will necessitate the same precautions.Barriers, signs, lights: The appropriate protective and warning devices should be erected before work begins. Barriers should be of the type approved according to the time they are to remain in place. Cones and drums should be used for temporary protection where mobility is desired.All traffic control signs should conform to recognized standards. Before work starts, all necessary signs should be set up generally at the side of the road with their near edge 2 to 4 m from the road edge

or at least 70 cm outside an unmountable curb. They should be mounted so that the bottom of the sign is at least 1.70m above the pavement. However, if obstructions such as equipment or parked cars are present, this height should be increased to 2.30m. Signs should be mounted at right angles to the line of traffic they serve. Advance warning signs should be spaced in

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accordance with their legend and prevailing highway speeds. Signs intended to convey a message at night should be reflectorised or illuminated. Light sources for night lighting include torches, lanterns, flashers and electric lights.Special care should be taken that supplies stored equipment and parked vehicles are not permitted to obscure signs. All signs should be inspected daily for legibility, proper position cleanliness and good repair. Damages signs should be replaced immediately.Electric or battery operated automatic red and green and/or amber flashing signals may be used in urban areas handling high volumes of traffic.Members of a work party should whenever possible wear bright coloured clothing.Shoring: Proper shoring is essential where traffic or machine set up

ground vibrations. Each trench or excavation will present unique problems due to variables such as soil structure, weather, hydrostatic pressure, nearness of structure etc. The safety officer with shoring experience should be consulted.

Vehicles: All trucks should be well marked with flashing amber lights and flags. They should be of a distinctive color which has a good target value. Each truck should be equipped with a small fire extinguisher, a first-aid kit and a reflector set.

Flagmen: Flagman should be used whenever traffic passing through the project is required or because of conflict with construction equipment or because the safe travel path cannot accommodate two way traffic. Since flagmen have frequent public contacts and are responsible for human safety, well qualified personnel should be selected as their supervisors. They should be of average intelligence, physically fir, have good eyesight and hearing and be mentally alert. They should manifest a courteous but firm manner, be neat and fully dressed, be of a calm disposition and have a sense of responsibility.

In performing their duty, flagmen should remain apart from any crowd so that they may direct the attention of traffic toward the hazardous condition. A flagmen never leaves his post until properly relieved, he always faces traffic while standing at the edge of a traveled roadway or in a barricaded lane outside the traffic lane, he

positions himself 50-80m from the end of the work area, in a location where he can see and be seen by motorist for at least 170m. A flag or light should never be used to signal traffic to proceed. Signals should be definite, a flag should never be waved. A flagman’s attire should consists of a white hat, red fluorescent vest and red fluorescent warning flag at least 50x50cm, mounted on a 1m staff.

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e) No persons shall be allowed to deepen drill holes which has been loaded with explosive agent.

f) No explosives or blasting agents shall be left unattended at the blast site.

g) No machines and equipment shall be operated within 50 feet of loaded holes.h) Power lines and portable electric cables for equipment being used shall be kept at a safe distance from explosives being loaded into the holes.i) Warning sign indicating a blasting area must be maintained at all approaches to the blasting area.

j) No loaded holes shall be left unattended or unprotected.

6.6. FIRING THE BLAST

Before a blast is fired, a loud warning signal should be given by the blaster, who has made certain that all surplus explosives are in safe place and all employees an equipment are at a safe distance.Flagmen should be positioned on highways which pass through the danger zone so as to stop traffic during blasting operation.It shall be the duty of the blaster to fix the time of blasting.

6.7. SAFETY MEASURES IN ELECTRICAL BLASTING :

Following safety measures are observed in Electrical Blasting :

a) Electric blasting caps should not be used where Sources of extraneous electricity make the use of electric blasting caps dangerous. Blasting cap leg wires shall be kept short-circuited until they are connected into the circuit for firing.

b) Before adopting any system of electrical firing, the blaster must check thoroughly for any external Sources of current, and it shall be eliminated before any holes are loaded.c) In any single blast using electric blasting caps, all caps shall be of same type and function and of same manufacture. d) Electric blasting shall be carried out by using blasting circuits or power circuits in accordance with the manufacturer’s recommendation.

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e) When firing a circuit of electric blasting caps, care must be taken to ensure adequate quantity of current is delivered in accordance with manufactures recommendations.

f) A power circuit used for firing electric blasting caps shall not be grounded.

g) When firing from a power circuit the firing switch shall be locked in the open or " OFF" position at all times, except when firing. Keys of this switch must be kept only with the blaster.

h) Blasting machines must be in good condition and the efficiency of the machine must be tested periodically to make certain that it can deliver power at its rated capacity.

i) The blaster shall be in charge of the blasting machines; no other person shall connect the lead wires to the machine.k) Blasters, when testing circuits to charged holes, shall use only blasting galvanometer equipped with silver chloride cell especially designed for this purpose.l) In electric firing only the man making leading wire connection shall fire the shot.m) After firing an electric blast from a blasting machine, the leading wires shall immediately disconnected from the machine and short-circuited.

6.8. INSPECTION AFTER BLASTING

Immediately after the blast has been fired, the firing line should be disconnected from the blasting machine, or where power switches are used, they should be locked open or in the off position.Sufficient time shall be allowed, not less than 15 minutes in tunnels, for the smoke and fumes to leave the blasted area before returning to the spot. An inspection of the area and surrounding should be made by the blaster to determine if all charges have been exploded before

workers are allowed to return back to operation, and in tunnels, after the muck pile has been wetted down.

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6.9. SAFE HANDLING OF MISFIRES:

If a misfire is found, the blaster should provide proper safeguards for excluding all employees from the danger zone.No other work should be done except that necessary to remove the hazard of the misfire and only those employees necessary to do the work should remain in the danger zone.No attempt should be made to remove explosives from any misfired hole. Another hole as to be drilled parallel to misfire and the new hole is blasted.

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5. SAFETY MEASURES FOR HOT MIX PLANT

5.1. SAFE WORKING & MAINTENANCE. Following safety measures are observed in Hot Mix Plant :

a) All motors and belt drives should be well protected. Workmen with loose clothing should be not be allowed.

b) Before starting the plant “Alarm Horn” should be sounded to alert workmen working inside the plant.

c) Non-smoking zone should be marked and properly highlighted.

d) Sufficient nos. of fire extinguishers should be provided and workmen should be trained on it.

e) Emergency shut down switches should be placed in well visible areas and highlighted properly.

f) Before starting pump 3 way valve should be heated externally to avoid jamming.

g) All nozzles should be made free from Bitumen jamming after each day’s work.

h) Drier drum burner should not be fired when drum is empty as it may cause bending of drum structure.

i) The plant should be cleaned everyday and made free of inflammable items like diesel, grease, etc. lying in unwanted places.

j) LIMIT SWITCHES of Safety devices should not be by passed in system.

k) Condition of LOAD CELLS for Hot Bitumen weighing bucket should be inspected every day, failure of which may cause overflow of Hot Bitumen.

l) Unauthorised persons should not be allowed inside the cabin.m) While carrying out any maintenance in Plant ensure that the power source is disconnected and under observation of a responsible person.

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2. 0. SAFETY MEASURES FOR MAJOR MECHINERIES 2.1. TIPPER AND LORRY. Follwing safety measures are observed

while operating Tipper and Lorry. a) While loading earth or material to a tipper the load should be

well distributed on the tipper body & while unloading it should be kept on a level ground.

b) Tipper should never be used for shifting manpower from one place to another.

c) Before traveling it should be ensured that the tipping level is fully disengaged. No lay man; except trained helper should be allowed inside the cabin.

d) Wheel Bolts, brakes, emergency brakes should be checked regularly.e) Reverse horn & light should be fittedf) Before starting the m/c attention is to be paid to the

equipment surroundings.g) While working under the fully lifted tipping body it should be

properly supported.h) Wheel should be jammed to prevent rolling of the tipper while

under repair.2.2. MOTOR GRADER Follwing safety measures are observed while

operating MOTOR GRADER:a) Examine the land and kind of soil at the work site.b) Inspect leakage in fuel, lubricant & hydraulic systems. Also

check tyre inflation & damaged parts.c) Don’t leave any parts or tools lying around.d) Check that all control levers are in neutral position.e) Don’t shift lever in ‘neutral’ or declutch while going down slope.f) Please ensure the blade is kept in diagonal position.g) Indication lights should be switched on at night.

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MANUAL OF SAFETY IN ROAD CONSTRUCTIONRBM. PATI JV

INTRODUCTION

1. General.This safety manual is prepared by RBM-PATI JV for the NHAI project of Widening to 4/6 lanes and Strengthening of Existing 2 lanes Carriageway of NH-6 in the State of West Bengal (Dankuni- Kolaghat) package WB-1. National Highway.

The functions of safety is to locate, define and rectify the operational errors that allows accident to occur. At RBM –PATI JV, We treat safety as an important management function.

2. Methodology.This manual describes in point form the major safety procedures to be observed by RBM-PATI JV while executing various operations of road construction works in this project (Package-WB-1)

Additional procedures shall be introduced whenever, during progress of contraction work, they are formed necessary, and forwarded to the Engineer of the project for their approval.

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2.3. SAFETY MEASURE FOR POCLAIN, EXCAVATOR & W-20 LOADER. Follwing safety measures are observed while operating Poclain, Excavator W-20 Loader :

a) Before starting operations, place must be properly observed (obstructions/overhead powerlines /marks for underground cabling)

b) For Poclain Swing area should be free from obstructions.c) Poclain should be placed horizontally while digging.d) Don’t use Poclain as lifting equipment or Loader for shifting materials.e) While idling loaded bucket should be restsed on groundf) After stopping m/c release all hydraulic pressure in system.g) Workmen should not be carried in W-20 buckets.h) Before removing any hose or working on hydraulic system air

pressure should be released form pressurized hydraulic tank of 90CK-III & W-20 loader.

i) Diesel soaked cotton waste/cloth should not be left on exhaust manifold/silencer.

j) While transporting 90 CK on road swing lock should be insrted.

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