Jean_Wong
Structural
- Sep 8, 2016
- 29
Good day!
I am designing an mse wall abutment (stub abutment supported by deep foundation). I have already designed MSE walls before the bridge abutment (along/parallel to traffic). In my understanding, if the conditions for back-to-back MSE walls in the NHI code are satisfied (length of reinforcement overlap, ratio of height of wall to width of railway, etc), then there would be no more retained fill consideration.
Would this be the case for the front MSE wall, perpendicular to traffic? Since the grids for the front mse wall would be overlapping with the mse walls from both sides?
Another issue that needs to be addressed is settlement. There is a 0.6m diameter high pressure water supply pipe 1.2m below N.G.L. and directly below the guideway. The height of the MSE wall at the abutment would be 8.0m from N.G.L. which would be fill/reinforced soil.
At the abutment area, the load from the girders would be transferred to the stub abutment supported by 3 drilled shafts which are positioned to avoid the pipe. Would there be significant downdrag from the shafts that would affect the pile? If so, what should be the minimum face to face distance of the shaft from the pipe?
In the other parts of MSE wall with heights ranging from 3.5m to 8.0m of reinforced soil above N.G.L., how is settlement prevented so that the pipe underneath would not burst?
I am designing an mse wall abutment (stub abutment supported by deep foundation). I have already designed MSE walls before the bridge abutment (along/parallel to traffic). In my understanding, if the conditions for back-to-back MSE walls in the NHI code are satisfied (length of reinforcement overlap, ratio of height of wall to width of railway, etc), then there would be no more retained fill consideration.
Would this be the case for the front MSE wall, perpendicular to traffic? Since the grids for the front mse wall would be overlapping with the mse walls from both sides?
Another issue that needs to be addressed is settlement. There is a 0.6m diameter high pressure water supply pipe 1.2m below N.G.L. and directly below the guideway. The height of the MSE wall at the abutment would be 8.0m from N.G.L. which would be fill/reinforced soil.
At the abutment area, the load from the girders would be transferred to the stub abutment supported by 3 drilled shafts which are positioned to avoid the pipe. Would there be significant downdrag from the shafts that would affect the pile? If so, what should be the minimum face to face distance of the shaft from the pipe?
In the other parts of MSE wall with heights ranging from 3.5m to 8.0m of reinforced soil above N.G.L., how is settlement prevented so that the pipe underneath would not burst?
