Which of the following is NOT typically a sign of settlement?

Answer: C — Plant growth

The correct answer identifies plant growth as not typically being a sign of settlement. Settlement generally refers to the vertical downward movement of a structure due to factors like soil compression, moisture changes, or insufficient foundational support. While various physical indicators can suggest that a structure is experiencing settlement, such as joint openings, cracks in concrete, and buckling of steel members, plant growth does not inherently indicate this issue. In fact, plant growth might occur in areas with sufficient moisture or nutrients, independent of the structural integrity of the nearby elements. Instead, the first three options—joint openings, cracks, and buckling—are direct manifestations of settlement or related structural problems. For example, joint openings can emerge as loads shift and the foundation settles, leading to misalignment. Similarly, cracks in concrete may develop as the materials flex or shift due to unequal settling, while buckling of steel members can occur when underlying support is compromised, causing excessive lateral forces. Hence, plant growth is not a direct sign of settlement, making it the correct choice in this context.