Precautions excavations

Plastic pipe for ground coupled heat pumps must withstand Installation at depths of approximately 1-2 m for horizontal systems or In vertical shafts as deep as 100 m In vertical systems without extraordinary excavation precautions, as well as ground settling after Installation, and thermal stresses during operation without failure. 

Deep excavation precautions appropriate to confined space entry may apply... 

Collecting samples of ancient nucleic acids is a delicate operation that requires what are basically surgical procedures. It is advantageous, whenever possible, that the samples be collected at excavation sites and precautions taken to ensure that they do not become contaminated with other, particularly more recent, nucleic acids. At high temperatures and humidity, nucleic acids decay quickly. Well-preserved ancient nucleic acids can, therefore, be expected in sites where low temperatures and a dry environment prevail, as, for example, in cold, desert areas of the world. Once collected, the samples need to be isolated from any other remaining materials until they can be amplified by PCR and their chemical composition and structure can then be studied. 

When found, the bomb should be handled with great precaution and not be turned upside down, because some bombs, (called "bombes a ren-versement ) explode on such movement. In order to prevent anybody else from such an action, the upper part of the bomb should be marked with chalk or pencil. Then the bomb is moved carefully into an excavation dug in a field, a cartridge of Dynamite or Tonite (provided with a primer and a 100 meter long piece of fuse), is placed over it and the ensemble covered with earth. Detonation of the cartridge explodes the contents of the bomb and shatters it to pieces... 

Excavation in order to remove drums and highly polluted waste. If the most contaminated waste in the landfill body can be identified, excavation may be an efficient remediation technique. Partly corroded drums may be difficult to handle without contaminating the waste material this is for precautions and care. The excavated material may be removed for off-site treatment or may be re-landfilled in landfill sections established with landfill liners, leachate drainage collection, and treatment systems. 

If chemical agent detector dogs are demonstrated to be able to reliably detect CWM at very low concentrations, this capability could be applied to assessing large CWM burial sites. For example, it is to be expected that some of the sites, or portions of some of the sites, are free of chemical agent because no CWM was buried in that section of the burial or only empty CWM containers were buried there.8 If chemical detector dogs could reliably confirm the absence of CWM, the excavation and removal of objects from portions of the burial pits so identified could possibly be carried out with reduced personal protective equipment and without other precautions normally taken for CWM excavation (negative pressure enclosures, for example). 

Both the pipeline operator and the excavator should take their precaution measures. The excavator has to write down the precaution measures and discuss them with the pipeline operator. 

It is accepted that excavations less than 1.2 m (4 ft) deep do not present a serious risk to those working in them. In any excavation of greater depth suitable precautions must be taken. 

Some confined spaces can be ventilated naturally. This is the case with most excavations. However, any time a naturally ventilated confined space is occupied, adequate precautions must be taken to prevent employee exposure to atmospheres containing less than 19.5 percent oxygen or to other hazardous atmospheres. Confined spaces that cannot be ventilated naturally must be ventilated with mechanical equipment. 

Employees must monitor for hazardous atmospheres to prevent the possible exposure to harmful levels and atmospheric contaminants. If oxygen levels are less than 19.5 percent the atmosphere must be tested before employees can enter. Oxygen-deficiency exposure precautions should include proper ventilation, respiratory protection, and mandatory testing. If hazards arise while employees are present in the excavation, emergency rescue equipment such as a breathing apparatus, safety harnesses, and stretchers should be readily accessible. 

Numerous precautions should be taken when excavating or working in trenches. 

While finalizing the layout of underground excavation, the high cover areas are generally avoided. If it can t be averted, appropriate precautions are taken. 

The decision as to which mining method to use for a particular deposit is governed by the nature of the ore body, safety, and economic considerations. In the case of underground uranium mines, special precautions, consisting primarily of increased ventilation, are required to protect against airborne radiation exposure. Excavation and in situ techniques are used to recover uranium ore. Excavation may be underground and open pit mining. 

Provide site security - particularly to stop children getting in °. Investigate the nature of the ground before excavations begin and decide the form that the support work will need to take and ensure that adequate supplies of sufficiently strong materials are available. Special precautions may be needed where trenches pass near adjacent roads or buildings. 

Excavations must be constructed so that they are safe environments in which construction work can take place. This means that they must be fenced and suitable notices posted so that neither people nor vehicles fall into them. However, there are many other precautions and controls that must be taken and several of these should have emerged during the communication and liaison with the occupants of adjacent buildings at the planning stage of the project. 

If excavation work is the only option available, the following precautions and controls should be adopted ... 

The following precautions are suggested when there is uncertainty about the location of underground services in an area to be excavated ... 

Outline the main precautions to be taken when carrying out excavation work. 

All successful oil and gas extraction work begins with proper site preparation, such as building the access road, leveling the site, ensuring the ground is stable, and digging the necessary trenches and excavations. Remember to take critical precautions when drilling... 

Electrocution from striking an underground cable can be spectacular when it occurs and the most effective precaution is to obtain clearance from the local Electricity Board or the location s electrical engineer that the ground is clear of cables. If doubt exists, locating devices are available that enable underground cables to be traced. Excavations near buried cables should be by hand. 

The precautions described in the preceding sections on bums and fires also serve to prevent the explosions consequent on short circuits in high fault level circuits. Reference should also be made to Chapter 12 for the relevant measures to avoid the explosions that can occur when an underground cable is damaged during excavation work. 

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