Beräkningsmetoder för flerbandssponter - Skillnader mellan metoderna och deras inverkan på resultatet.

2018 a new guide for designing retaining structures was published, which describes different methods for designing sheet pile walls. This master thesis aims at comparing and analysing these methods to find out how results obtained using them differ from each other and how well they correspond to measured values. The result shows that the methods in some aspects differ signicantly while in other aspects the methods are well-matched. As a reference project a sheet pile wall from Dingersjo, outside Sundsvall, is used. This master thesis has been carried out at the Department of Construction Sciences at the Faculty of Engineering LTH at Lund University in collaboration with Peab Anläggning AB. The guide for designing sheet pile walls (Sponthandboken 2018) describes three different calculation methods; the analytic method, the spring method and the finite element method. The analytic method is the simplest and least time-consuming method where calculations are performed manually. In the spring method the sheet pile wall is modelled as a beam with springs that replace the passive soil pressure. Anchors have also been modelled as springs. For the spring method the computer program Frame Analysis has been used. Finally, for the most advanced method, the finite element method, the computer program PLAXIS 2D has been used. For all methods, a model has been set up that resembles the sheet pile wall in Dingersjo. Calculations have been performed for anchor forces, bending moments and displacements of the sheet pile wall. In contrast to the other methods, the analytic method can not calculate displacements. Anchor forces calculated in all methods are well matched with measured anchor forces. The magnitude of the bending moments calculated using the different calculation methods varies greatly, however, all methods show the greatest bending moment in about the same position of the sheet pile wall. In the studied case the spring method gives the largest dimensioning bending moment and the finite element method gives the smallest. The dimensioning bending moment calculated using the spring method is just over three times as large as the dimensioning bending moment from the finite element method. The dimensioning bending moment calculated using the analytic method is almost twice the dimensioning moment from the finite element method. The result of the calculated displacements differ between the spring method and the finite element method. In conclusion, it is stated that the analytic method is a simple method that is least time consuming and is suitable for uncomplicated projects while the finite element method should be used for more complex projects and where more detailed investigations have been carried out.Spont är en stödkonstruktion som används som hjälpmedel vid djupa schakt och vid grundläggning av konstruktioner. Spontens uppgift är att hålla emot det jordtryck som uppstår mot sponten vid schaktning. Det finns flera beräkningsmetoder för att dimensionera en spont, från en enklare handberäkning till en mer avancerad beräkning med finita element. Dessa beräkningsmetoder har jämförts och analyserats för att utvärdera lönsamheten med respektive beräkningsmetod