Evaluation of the Volume Measurement Optical Method Suitability for Determining the Relative Compaction of Soils

The goal of this paper is evaluation of the volume measurement optical method suitability for determining relative compaction of soils. The Structure for Motion technique was utilized in order to achieve the goal by making the three-dimensional models (with Bentley ContextCapture software). Created models were used in volume measurement of the pit-holes. The results were compared with the basic methods: the sand cone test and the water method. The laboratory tests were carried out in two stages. In the first stage, the optical method was tested in similar to operating conditions. Ten holes were made in the soil and the volumes were measured with three different methods. The results were compared and submitted for statistical analysis. Statistical analysis showed the potential of optical method. The second laboratory test focused on repeatability and accuracy of measurement. The volume of the vessel imitating a pit-hole was obtained. The results of the second stage showed that the optical method has better accuracy and lower statistical dispersion compared with sand method. On this basis it can be concluded that optical method of volume measurement has great potential in soil compaction testing

From legend to discovery – historical and geotechnical conditions related to the discovery of tunnels under The Castle Hill in Szczecin

The historical past of a building has a key influence on the variability of geotechnical conditions. These conditions change with a modification of the structural system, a change in function or only architectural elements (fashionable in a given period). In the article, various geotechnical and geophysical surveys are described, which led to a discovery of potential causes of a structural failure at historical Castle of Dukes of Pomerania in Szczecin. The investigation resulted in a discovery of an underground tunnel system constructed under the Castle, which existence was only suspected. The tunnels were constructed primarily during II World War, but also before that period. The article summarizes facts discovered due to investigation as well as historical and geological background related to the execution of the reinforced concrete and masonry tunnels. The lesson learned resulting from this discovery is that great care should be taken when historical areas are considered, even if the structure seems to be massive and robust

Praktyczne aspekty prac polowych wykonywanych metodą tomografii elektrooporowej

The following article collects and describes several practical problems that can be encountered when performing geophysical field measurements using the electrical resistivity tomography (ERT) method. The methodology of work carried out with the Terrameter LS apparatus of the Swedish company ABEM (currently the company has changed its name to GUIDELINE GEO) was presented and discussed. The attention was paid to interesting solutions that increase the efficiency of works, especially in works related to linear investments. Errors that may appear during the use of the roll-along method are indicated, in particular, those appearing in measurements where too long measurement sections are transferred, as well as problems resulting from high electrode earthing, nonlinear profile traces and variable morphology. It describes how the use of different measurement systems affects the depth of prospecting, and which systems cope well in the area with disturbances. The article also emphasizes that the work should be properly planned before starting field research.W niniejszym artykule zebrano i opisano kilka praktycznych problemów, z którymi można się spotkać w trakcie wykonywania geofizycznych pomiarów polowych, stosując metodę tomografii elektrooporowej (ERT).Przedstawiono i omówiono metodykę prac wykonywanych aparaturą Terrameter LS szwedzkiej firmy ABEM (obecnie firma zmieniła nazwę na GUIDELINE GEO). Zwrócono uwagę na ciekawe rozwiązania, które zwiększają efektywność prac, szczególnie w pracach związanych inwestycjami liniowymi. Wskazano błędy jakie mogą pojawić się podczas stosowania metody roll-along, w szczególności pojawiające się w pomiarach gdzie przenoszone są zbyt długie sekcje pomiarowe, a także problemy wynikające z wysokich uziomów elektrod. Opisano jak stosowanie różnych układów pomiarowych wpływa na głębokość prospekcji, a także które układy radzą sobie dobrze w obszarze z zakłóceniami. W artykule zwrócono uwagę na to by w odpowiedni sposób planować prace przed przystąpieniem do badań terenowych

Preliminary validation of the dynamic probing methods used in estimation of the relative density of cohesionless soils

The dynamic probing methods are commonly used for the subsoil identification. For example, the relative density/density index (ID) of cohesionless soils can be determined by using appropriate correlation relationships. The results obtained by various probing methods (DPL, DPH, DPM) may vary from one to another. Thus, the field tests were conducted in order to determine how important these discrepancies are. Each of the above mentioned methods were performed 10 times at one location. The effect of the influence of the penetrometer type on the relative density estimation results was determined. Based on the analysis, it can be concluded that the results obtained by the medium and heavy penetrometers are very close to each other. On the other hand, the discrepancies between the results obtained with the light penetrometer and the other two penetrometers are greater, both in terms of mean difference and scatter

A Novel Approach to the Analysis of the Soil Consolidation Problem by Using Non-Classical Rheological Schemes

The paper presents classical and non-classical rheological schemes used to formulate constitutive models of the one-dimensional consolidation problem. The authors paid special attention to the secondary consolidation effects in organic soils as well as the soil over-consolidation phenomenon. The systems of partial differential equations were formulated for every model and solved numerically to obtain settlement curves. Selected numerical results were compared with standard oedometer laboratory test data carried out by the authors on organic soil samples. Additionally, plasticity phenomenon and non-classical rheological elements were included in order to take into account soil over-consolidation behaviour in the one-dimensional settlement model. A new way of formulating constitutive equations for the soil skeleton and predicting the relationship between the effective stress and strain or void ratio was presented. Rheological structures provide a flexible tool for creating complex constitutive relationships of soil

Using Electrical Resistivity Tomography (ERT) as a tool in geotechnical investigation of the substrate of a highway

Geo log i cal and geotechnical en gi neer ing field tests, like struc ture drillings and dy namic (DPL, DPSH) or static probing (CPT), are con sid ered for a fun da men tal source of in for ma tion about soil and wa ter en vi ron ments. Since Eurocode 7 has been in tro duced, it has be come more com mon to use also dilatometers (DMT) or pres sure me ters (PMT). Re sults ob tained us ing all the men tioned tests are al ways of a dis crete na ture – in for ma tion is pro vided in cer tain points in the field. How ever, they de ter mine the ba sis for cre at ing spa tial mod els of geo log i cal struc ture and geotechnical con di - tions of a sub stra tum. The range and num ber of in ves ti ga tions con ducted (in clud ing drill ing, prob ing and lab o ra tory tests) in flu ence pre ci sion, in which a geo log i cal struc ture is iden ti fied and thus, also af fect prob a bil ity of com pat i bil ity be tween spa tial model and real geo log i cal con di tions of a sub stra tum. In the pa per, re sults of non-in va sive elec tri cal re sis tiv ity to mog ra phy (ERT) method are pre sented, com pris ing 2-di men sional im age of a soil me dium re sis tance. Elec tri cal re sis tance is a pa ram e ter that re flects di ver si fi ca tion of a soil me dium, con sid er ing its lithological as pect. In ad di tion, when com bined with drill ing re sults, it can be used to ac cu rate de ter mi na tion of bound aries be tween soil lay - ers. Car ry ing out of ERT tests in the field dur ing ex press way con struc tion con trib uted to iden ti fi ca tion of weak, low-strength soils like or ganic soils (peat, aggradated mud) and of soft con sis tency co he sive soils. These kinds of soil are the main cause for un ac cept able de for ma tions ap pear ing in the new road en gi neer ing struc ture

A Novel Approach to the Analysis of the Soil Consolidation Problem by Using Non-Classical Rheological Schemes

The paper presents classical and non-classical rheological schemes used to formulate constitutive models of the one-dimensional consolidation problem. The authors paid special attention to the secondary consolidation effects in organic soils as well as the soil over-consolidation phenomenon. The systems of partial differential equations were formulated for every model and solved numerically to obtain settlement curves. Selected numerical results were compared with standard oedometer laboratory test data carried out by the authors on organic soil samples. Additionally, plasticity phenomenon and non-classical rheological elements were included in order to take into account soil over-consolidation behaviour in the one-dimensional settlement model. A new way of formulating constitutive equations for the soil skeleton and predicting the relationship between the effective stress and strain or void ratio was presented. Rheological structures provide a flexible tool for creating complex constitutive relationships of soil