An example of the application of a filtration model to the prediction of the influence of a deep-founded building on groundwater level changes

Większość obecnie budowanych obiektów wielkokubaturowych, wyposaża się ze względów ekonomicznych w kondygnacje podziemne użytkowe lub z przeznaczeniem na miejsca parkingowe. Bardzo ważnym jest, by już na etapie projektowania zaplanować optymalny, ekonomiczny i bezpieczny system odwadniania, a także zaprojektować rozwiązania techniczne mające na celu eliminację oddziaływań części podziemnej obiektu na zmiany stanów wód podziemnych w jego sąsiedztwie. Zastosowanie matematycznych modeli filtracji wód podziemnych pozwala na przeprowadzenie prognozy oddziaływania procesu odwodnienia wykopu, a także ustalenia wpływu nowo budowanych obiektów na zmianę stosunków wodnych na danym obszarze, w czasie budowy jak i w okresie eksploatacji obiektu. W artykule przedstawiono przypadek wykorzystania modelu filtracji wód podziemnych w programie SPRING do budowy obiektu handlowego, zlokalizowanego w ścisłym centrum Budapesztu. Projekt obejmuje budowę dużego obiektu z garażem podziemnym. Wykorzystując model filtracji, dokonano oceny zmian pola przepływu wód podziemnych, będących skutkiem wykonania obiektu oraz prowadzenia odwodnienia wykopu fundamentowego. Wykonano także prognozę zmiany poziomów zwierciadła wód gruntowych wokół obiektu z uwzględnieniem oddziaływania fali powodziowej w Dunaju na teren inwestycji. Na podstawie wyników obliczeń modelowych zaproponowano stosowne rozwiązania inżynierskie w celu ograniczenie wpływu na obiekty sąsiadujące oraz potencjalne zmiany stosunków wodnych w obszarze planowanej inwestycji.Nowadays, for economical aspect, most of large cubature objects are constructed with underground storeys or car park areas. During the planning phase, it is important to design an optimal, economical and safe dewatering system and technical solutions aimed to eliminate the influence of underground structure on groundwater levels in the neighbourhood. Mathematical modelling of groundwater filtration allows creating a prognosis of excavation dewatering process and influence of new buildings on groundwater levels in subject areas during both execution and operation of structure. The paper presents an example of groundwater filtration modelling for a shopping mall in the centre of Budapest, using SPRING software. The project includes the construction of a large building with an underground story for cars. With filtration models, it was possible to assess the changes in groundwater flow fields caused by projected structure and its excavation dewatering system and the prognosis of groundwater levels around the building, taking into consideration the influence of the flood wave from the Danube on groundwater filtration in the investment area. Based on modelling results the suitable technical solutions were proposed, which allow limiting the effect on the surrounding buildings and the potential changes of water levels in the investment area

Peat consolidation -- new approach

The problem of consolidation of soil has been widely investigated. The basic approach was given by Terzaghi who assumed soil of constant physical and mechanical parameters. In the case of peat consolidation, the permeability coefficient of soil and the elasticity modulus are functions of the settlement which is an important additional factor. The model proposed here assumes varying the elasticity and permeability coefficients. Moreover, the settlement is described by the so-called elementary curve which was approximated empirically based upon laboratory tests. The model allows to consider the case when the filtration in the peat body goes in horizontal direction. It happens so when the charging layer does not receive outgoing water from the pores. The model includes also the case when the load involving consolidation varies in time i.e. the charging layer grows up gradually. The model has been applied practically in several cases and it comes that there is a good agreement between calculated and measured settlement of the consolidated peat layer

Peat Consolidation – New Approach

The problem of consolidation of soil has been widely investigated. The basic approach was given by Terzaghi who assumed soil of constant physical and mechanical parameters. In the case of peat consolidation, the permeability coefficient of soil and the elasticity modulus are functions of the settlement which is an important additional factor. The model proposed here assumes varying the elasticity and permeability coefficients. Moreover, the settlement is described by the so-called elementary curve which was approximated empirically based upon laboratory tests. The model allows to consider the case when the filtration in the peat body goes in horizontal direction. It happens so when the charging layer does not receive outgoing water from the pores. The model includes also the case when the load involving consolidation varies in time i.e. the charging layer grows up gradually. The model has been applied practically in several cases and it comes that there is a good agreement between calculated and measured settlement of the consolidated peat layer