Improving soil bearing capacity — identify the method that does NOT help Which of the following actions does not improve the bearing capacity of soils for foundations?

Introduction / Context:
Bearing capacity enhancement methods reduce settlement and increase allowable loads by densifying, draining, or reinforcing the ground. Choosing the correct technique depends on soil type, groundwater, and structural demand. This question asks you to spot the option that does not contribute to improvement.

Given Data / Assumptions:

• Sandy and cohesive soils may both be encountered.
• Ground improvement aims to increase effective stress or soil structure.
• Surface watering means adding water without controlled densification.

Concept / Approach:
Effective methods include drainage (to increase effective stress and reduce pore pressure), densification via ramming or vibro techniques, and installing granular or sand piles to reinforce and drain the soil mass. Simply watering the surface generally reduces shear strength in many soils (especially clays) and can loosen near-surface sands, thus decreasing bearing resistance and increasing settlement risk.

Step-by-Step Solution:

Verification / Alternative check:
Observations from field practice show settlement and bearing failures often follow excessive wetting of foundations without countermeasures.

Why Other Options Are Wrong:

• Drainage: well-established improvement technique.
• Crushed stone ramming: increases density and stiffness.
• Sand piles: improve and drain soft ground.
• None of these: incorrect because one option is clearly not helpful.

Common Pitfalls:
Assuming water aids compaction in all soils; for clays, added water can reduce strength; for sands, uncontrolled wetting may cause loosening.

Final Answer:
watering the surface of soil