Precompression in Soil Consolidation: A Solution to Postconstruction Settlement Problems

Precompression-General Considerations Precompression of soil is a technique used to eliminate postconstruction settlement problems that may arise when highly compressible, normally consolidated clayey soil layers are located at a limited depth. This technique is commonly employed in the construction of large buildings, highway embankments, or earth dams. The principles of precompression can be explained by considering the structural load per unit area, denoted as \( \Delta p_{(m)} \), and the thickness of the clay layer undergoing consolidation, denoted as \( H_{e} \). The maximum primary consolidation settlement caused by the structural load, denoted as \( S_{(m)} \), can be calculated using the following equation: \[ S_{(G)}=\frac{C_{c} H_{c}}{1+e_{e}} \log \frac{p_{0}+\Delta p_{(p)}}{p_{0}} \] The settlement-time relationship under the structural load follows a specific pattern, as illustrated in Figure \( 12.14 \mathrm{~b} \). However, if a surcharge of \( \Delta p(n) \) is applied to the soil layer, the settlement-time relationship will change. In conclusion, precompression of soil is an effective technique to mitigate postconstruction settlement problems in clayey soil layers. By understanding the principles of precompression and its impact on settlement, engineers can design structures that minimize long-term settlement issues.