Geological engineering and geophysical engineering surveys

Geological engineering surveys

Geological engineering surveys are the part of engineering geology research focused on considering of geological conditions of proposed sites of different industrial and civilian projects.

Some undesirable constructive changes might appear as a result of interaction between the structure being designed and environment. Forecasting of these changes is the essential point of geological engineering surveys.

Scope and content of geological engineering surveys are determined by the degree of complexity and level of knowledge of natural conditions of the proposed site region and project purpose. Geological engineering surveys are regulated by construction code SNiP 11-02-96 («Engineering Surveys for Construction. The Fundamentals»).

The structure of geological engineering surveys comprises:

field inspection of the facility being considered;
shaft-sinking and tunneling — geological engineering wells drilling by various methods: with earth auger, air-leg rock drill (blowing down or washing), rotary-percussion drilling using pneumatic percussion tool;
thermometric measurement in permafrost sections;
soil testing by static probing and rotary cut method.

Examples of integrated geological engineering surveys.

	Geological engineering surveys for Karskaya station sites of the design «Construction of Bovanenkovo oil and gas condensate field cenomanian-apt deposits», 2009.

	Geological engineering surveys for Zapolyarnoe gas-turbine power station, 2009.

	Integrated geological engineering surveys for the investment project «Gas pipeline Kirinskoye gas-condensate field onshore processing facility - base compressor station ‘Sakhalin’». Surveys were at the length 74.3 km — 135.6 km. 2010.

	Performing integrated geological engineering surveys for the design «Gas main pipeline Yakutia — Khabarovsk — Vladivostok». Chayanda — Lensk section. 2011.

Geophysical engineering surveys

Geophysical engineering surveys are the part of geological engineering research within all stages of its performing (design, detail documentation).

Geophysical engineering surveys are necessary for specifying the data recieved by geological drilling. It increases the information value of geological engineering surveys.

The essential geophysical engineering techniques

Exploration seismology,
electrical exploration,
ground-penetrating radiolocation.

Within geological and geophysical engineering surveys Ingeocom LLC accomplishes the following tasks:

Study of landslide processes, mapping of soil sliding surface, detection of landslide foot thickness and depth, ground-water level, humidity testing of soils;
Study of karstic processes, geological and geophysical attributes of conditions within the karst rocks forming areas, detection of karst cavities with different fillings;
Study of physical parameters and lithological profiles of upper part of the geological section including the areas of permafrost;
Detailed study of country rocks at highway bridge crossings, oil and gas main pipelines, sections of pipelines underwater crossings, areas of designing industrial and civil constructions;
Detection of thickness of motor roads and construction sites filled-up ground;
Detection of soil bearing capacity and dynamic response.

	A fragment of geological profile along the gas-main pipeline «Bovanenkovo — Ukhta». Geophysical surveys were performing at the stage «Detail documentation» of the design. Their purpose was the detailed study of the upper part of geological cross section. Geophysical methods package included vertical electrical sounding, refracted wave method and comprehensive interpretation of acquired data.

	Scheme of geophysical profiles location at the section of main pipelines «Bovanenkovo — Ukhta» underwater crossing through the Chernaya River.

	Consolidated geophysical profile along the main pipeline route «Bovanenkovo — Ukhta» at the section of underwater crossing through the Chernaya River. Surveys for the underwater crossing were performed as thin ice on the river did not allow for drilling geological engineering borehole. Main purposes of surveys included vertical geological column, locating geological boundaries and forecasting lithological structure and permafrost conditions in riverbed area between key riverside wells.

	Сonstruction of Kharasaveiskoye gas condensate field. Scheme of apparent formation resistivity distribution. Data of vertical electrical sounding. The purpose of integrated engineering surveys for Kharasaveiskoye field was obtaining the data on peculiarities of natural conditions and its spatial changeability within the area of allotment. Surveys were performed with the use of vertical electrical sounding and common depth point method.