Question Two:

a$)$ An engineer is tasked with assessing the vertical stress exerted on a point located $2\mathrm{.}5$ meters below the ground surface, labelled as point A in the diagram. Two concentrated losds, $P_1=350kN$ and $P_2=470kN,$ are applied on the ground surface at different horizontal distances from the point directly above $A.$

Given the following details:

$P_1$ is located $2\mathrm{.}3$ meters horizontally from the point directly above $A.$

$P_1$ is located $1\mathrm{.}1$ meters horizontally from the point directly above $A.$

Determine the vertical stress at point A due to the combined effect of both loads, and discuss any assumptions about the distribution of stress within the soil that may impact your calculation.

b$)$ An engineer is analyzing the impact of a uniformly distributed load of $q=250k\frac{N}{m^2}$ applied over a flexible rectangular foundation area, as shown in the figure. The engineer needs to calculate how this lood affect: the subsurface stress distribution at specific points of intereat. For a depth of $=3m$ beneath the surface, determine the increase in vertical atress $({}_z)$ under points $A,B,$ and $C.$ Given the relative positions of these points to the loaded area, consider whether the effect of the load would vary at esch point and explain the aszumptions involved in your calculations regarding stress distribution.