Geotechnical Design Exercise for a Multi-Span Bridge Foundation

There are no word limits for this assignment. The assignment is mainly calculations and a bit of sketches. I will attach a brief which explains everything in detail. I can send presentation slides as well if needed.

This coursework provides the opportunity to perform a geotechnical design exercise. Based on data rom in situation and laboratory tests you will practice the design of different foundation systems for a multi-span bridge and you will have to decide on the optimum foundation system based on rational nd well documented assumptions. Thus, you will improve your design and problem-solving pabilities and you will demonstrate your engineering judgement skills. Furthermore, this ursework being a group project, enables the development of communication skills and improves our team working capacity. 

For the construction of a new A road over a valley, a multi-span bridge will be constructed. As path the highway's civil engineering works design team you are asked to perform a preliminary design f the bridge's foundation. The soil profile in the area consists of a layer of silty clay which overlays silty sand layer, the latter resting on the rocky bedrock of the area. The depth of the water table at he area is halfway down the depth of the Silty Clay layer. The soil profile is presented in Figure 1 hile the corresponding thickness of each layer is given in Table 1 

-For the preliminary evaluation of the geotechnical conditions a set of borstal's was realized in the alley along the bridge alignment. The investigation campaign included Standard Penetration Tests SPT) and the measured average values for the two layers are given in Table 2. Moreover, invited aboratory investigation on borehole samples revealed the index properties and some of the chanical parameters for the two layers as presented in Tables 3 and 4 for the silty clay and the ilty sand layers. respectively. 

-The initial bridge design proposes a simple multi-span bridge with spans of 12m between individual liars. A typical section of the bridge at a pillar location is given in Figure 2. while the presented uniform load of 300kNfm2 represents both the dead and the live load of the bridge and has already been property factored. ft can be directly used to calculate the total load acting on the foundation system by assuming that it also accounts for the weight of the pillar itself. Figure 3 shows a plan view of the bridge deck which has a width of 7m. The length of the altar Is 5m and its width 0.70m. In terms of loading, apart from the vertical load, the structural analyses indicates mat the badge imposes to the foundation system momentsequal to 30% of the vertical load In both directions.