Grain Storage Structures and Silos

According to Janssen's theory for grain silos, the lateral pressure $P_L$ at depth $h$ is related to vertical pressure $P_v$ as:

Options:

• (A) $P_L = k P_v$, where $k = \frac{1 - \sin\phi}{1 + \sin\phi}$
• (B) $P_L = P_v / k$
• (C) $P_L = P_v \sin\phi$
• (D) $P_L = P_v$