Among the works related to the design of structures, one of the most important is the calculation of their foundations. The purpose of the geotechnical studies is to provide design team need to carry out the calculation and reliable baseline data. The adequacy of geological data depends on how it was organised and executed drilling under the Foundation; the price of complex research are also mainly determined by the drilling works.
the Task of drilling for the Foundation
Drilling under the Foundation concrete of a building is usually carried out before the final phase of design, when the first was already resolved all the issues related to the General development planning. Therefore, the objectives of drilling at the site of the Foundation includes a detailed specification of ground, hydrogeodynamic and hydrogeochemical conditions in the border facilities and in close proximity to him in order to making final design decisions about the form of the Foundation and its calculations. Also on the basis of obtained geological information justify methods of execution of earthwork construction.
the Basic requirements during the planning of the volume of drilling under the Foundation
- boreholes should lay:
- along the boundaries and axes of the structures;
- at the points where the expected change in load on the ground;
- in the places of changing geomorphological elements of the area;
- at the points where it is planned to change the depth of the Foundation.
- to clarify the geological settings, the presence of nearby undesirable geological phenomena, it is necessary to plan the drilling of wells beyond the projected structures in the surrounding area. the
- Total number of drilling wells within the area of buildings of the 2nd level of responsibility – three or more, and 1 level four, and more.
- in the design of Foundation tape type is:
- minimum depth of wells to be tested at four meters deeper than the base of the soles in the absence of groundwater and six metres at their meeting;
- if the Foundation rests on rock rocks, can be reduced depths up to one meter below the soles of his feet;
- to design individual objects 3 level of responsibility (utility, storage structure) in a simple geologic conditions drilled one or two engineering-geological wells.
- depth of drilling when designing the pile Foundation must be supported in the preparation of survey programme, taking into account the area of the pile field and the total load. Typically, the drilling in this case is 5-10 metres below the level of penetration of the ends of the piles.
- For slab Foundation depth of drilling is recommended to set equal to 1/2 the width of the base plate. Thus it is necessary to monitor the following conditions:
- the number of wells under a single Foundation – at least 3;
- depth of each well should be at least 20 m;
- between the points of drilling should not be more than 50 m.
How is the drilling for the Foundation price
the Estimated price of drilling is set individually for each object. The main factors that determine the final price:
- distance from base of drilling contractor's works;
- the required number of wells and their depth;
- categories of drillability of rocks under the Foundation;
- used in the drilling technique.
a Quality source of geological data for the calculation of the Foundation for a reasonable and transparent price you can get, entrusting survey work the company "Guild Engineering".