engineering-geological works are wells and pits. It can be used virtually all of the main drilling methods: auger, core barrel, shock and vibration cable. Select this method of drilling, to provide the best possible core recovery. When the percussion-rotary method for the destruction of rocks are used chisels. Rock collapses from shock or rotational effects. Use the following drilling tools: core pipe, augers, glasses, probes, drills. For drilling in geological engineering is often used drilling rig URB-2A2 and PBU-2, rarely use other machines.
Choose a method of exploration based on the type of the future building is possible only for engineering-geological conditions of the 1st category of complexity. For 2nd and 3rd categories of complexity parameters of intelligence largely determined by soil characteristics, geological conditions. This applies particularly to soft ground: swelling, subsiding, etc.
For drilling through rock is taken as the minimum diameter of the bore is 89 mm, sand-clay varieties over 108. the Method of penetration is chosen such as to preserve the natural settings of the monolith, and come from a techno-economic feasibility calculations drilling in various conditions. For different geological conditions, different soils are different kinds of drilling. For example, experimentally, the shock and vibration cable ways most fruitfully used in the field of distribution loam (loess and moraine).
When large volumes of work and when we are dealing basically with the same type of geological conditions – choose high-performance drilling methods: vibratory, vibratory rotary and air percussion. When drilling activity is not significant – widely used method of drilling for most soils. Such a widespread way is core drilling. This method of drilling can be used in all the rocks to a considerable depth, with the possibility to save in original natural soil properties. Diameter drilling with this method is limited. Drilling is mainly produced "dry", often used the sampler receiver; type. In this way, the bottom hole is blown with compressed air.
For hydrogeological purposes, a shock-cable and rotary drilling methods.
But whatever drilling method was not used when engineering-geological surveys – all methods are applied grunthos. Use different type grunthos to the magnitude of the depth of from one and a half their diameter to 0.4 M. In hard and semi-hard clay soils are used in the receiver; gronthos, and press grunthos used in plastic loamy soil, megaplatinum and temacapulin soils. Grunthos is the devices which are selected monoliths. There are different grunthos intended for monoliths of different sizes. The inner diameter of the sampler according to GOST 12071/72 is taken over 90mm. Accordingly, the diameter of a drilled well must be greater than 127 mm. This type of wells refers to technical with diameter from 127 to 325 mm. Such wells are used for sampling undisturbed soil structure, test cut, die trials, etc.
the Distance between holes is selected depending on geological conditions and depending on the class the responsibility of buildings and structures. And well depth is selected depending on the number of storeys of the building, which determines the load on the Foundation. In the presence of, or absence of water in the rocks is necessary or to increase the depth of drilling, or reduce it. In the presence of rocky soils the hole should be drilled at 1-2 m below the base of the Foundation, or the surface kabuliwallah soils.
When planning the location of soil borings should be taken into account access equipment, roads, relief, land. Also be aware of the early wells were drilled and used in the calculation of these data.