Influence of the excavation work and construction process of the 57 residencial buildings and its effect on the tunnel vault of line 12 of Madrid´s Subway through a 2D analysis.
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According to Rankine's State Theory, due to the movement of the wall, a progressive horizontal relaxation will occur in the active zone until the breakage is reached:
The simulation of the non-linear behaviour of the soil and the excavation process will be carried out using the DRUCKER PRAGER constituent material model.
The project consisted of 8 phases:
-Construction of the pile screen
-Excavation process
-Construction process of the nearest pile casing
-Application of building loads on the waling and perimeter wall slabs
-Emptying the pool tank
-Construction of the pool piles
-Construction of the bottom and walls of the pool and the exterior soils filling
-Application of full pool loads
Phase 6: Construction of the pool piles
Tunnel section´s displacements
Maximum (traction) and minimum (compression) main stresses: Maximum stresses are produced in the lower right gable, with compressions of 8.69 MPa in the inner part and traction of 5.92 MPa due to the negative moments of the gable's recess with the base.
Representing the variation of tensions between the initial and final state, the results are:
Virtually all relative displacement occurs during the excavation process. Therefore, in order to meet the deformation rate of <2mm/week, this excavation process should be carried out in two weeks in the areas of the pile screen closest to the Subway infrastructure.
The increase in tensions is low. The largest increases in traction occur in section 1, from 1,432 to 2,382 MPa, values below the concrete cracking stress.
Therefore, and based on the results obtained, the new work will not affect the effects of stress or deformation of the infrastructure