The Cathedral of Vilnius is one of the main architectural monuments in Lithuania. This structure was built in unfavourable geological conditions. Due to this reason, the foundation of the building subsides; there occur wall deformations and cracks. Preservation of the building is today’s urgent problem. When evaluating the geologic environment from the perspective of engineering, construction works require deep analysis of the following key environment components and discuss them: relief, soils of geologic structure and their geotechnical properties, conditions of underground water occurrence and geological processes, and condition of the foundation. The article provides the brief history of construction and reconstruction of the Cathedral based on archival studies, the description of engineering geological conditions, and the archeologic and historic material of the evaluation of the foundation.

The purpose of the investigation is to assess local clay soils of different composition, physical state and mechanical properties as a base and construction material for establishment of landfills for radioactive waste. The investigations have been carried out for three clay soil types of different age and origin in order to assess the potential of this clay to be used for the establishment of engineering barriers, as well as the base and slopes of landfills. The investigations have been performed by laboratory and field methods for both the natural as well as the disturbed and compacted soils. In order to assess the soil to be used for fill-ins (aggregate), field investigations have been performed at a special test site. Changes in geotechnical features of the soils were observed at the test site in autumn and spring. Seasonal investigations enabled to assess the compacted clay soils according to changes of their features over time.

The undrained soil strength is specific to fine soils or to sands with a lot of fines. It is very important characteristic and the evaluation of accurate value is significant step. The undrained soil shear strength can be estimated directly in laboratory and indirectly in field using in-situ methods. The values of undrained shear strength estimated with different methods usually are different, sometimes very much. In geotechnical practice a lot of empirical equations are used to calculate undrained shear strength (cu), however it corrects only in specific conditions and can’t be used universally. The empirical factor (Nk), which is used in mentioned equations, varies in wide range. It depends on many factors. The research of glacial genesis fine soils (various moraines) is complicated because it specific grain size distributions and genesis. In this article we will study relation between different laboratory and field methods to estimate of undrained shear strength (cu) of till soils. For these purposes we will used upper Pleistocene, upper Nemunas formation till fine soils.

Road and foundation deformations in modern Lithuanian construction are one of the most important problems. Constantly rising conflicts between customers and builders due to poor quality of foundations show that Lithuanian road builders do not ensure proper quality of work, do not perform the necessary road foundations and research, do not carry out continuous control of their work. One such example was the construction of the Pagegiai wind farm in 2014÷2015. Improperly installed road and crane installation foundations have forced the wind power plant to stop working, which resulted in enormous losses. Additional cluster engineering geological surveys that included a full range of field and laboratory work made it possible to identify the causes of poor quality work and to properly assess the properties of substrates and primers that are important for safe foundation operation.

Santrauka. Straipsnyje nagrinėjama polių, įgilintų į smėlingą dulkingą molį, ir pagrindo sąveika. Apžvelgiami eksperimentiniai ir teoriniai darbai. Pateikiama gruntų geologinė litologinė sandara, modelio sudarymo metodika. Sumodeliuotas eksperimentas, išanalizuotos grunto judėjimo kryptys. Atlikti lauko ir laboratoriniai tyrimai, jų analizė ir pateiktos grunto pasiskirstymo schemos. Apskaičiuotas grunto pakilimas aplink polius. Sudarytas fizinis modelis remiantis jau anksčiau nagrinėtu fiziniu modeliu ir jo pagrindimu.