Which CBR rating requires soft soil anchor installation?

Which CBR rating requires soft soil anchor installation?

• A. 15-25 requires soft soil anchor installation
• B. Less than 15 requires soft soil anchor installation
• C. Greater than 30
• D. Not specified

Answer: (B)

A low CBR means the soil is weak and has limited bearing capacity, so additional stabilization is needed to keep loads from causing excessive settlement or movement. Soft soil anchors are installed when the CBR falls below 15 to enhance restraint and transfer load more reliably into the ground. Once the soil is stronger (CBR in the 15–25 range or above 30), the natural bearing capacity is typically sufficient, so soft soil anchors are not ordinarily required. “Not specified” offers no concrete criterion, whereas the low end threshold provides a clear rule of when such anchors are needed.

A low CBR means the soil is weak and has limited bearing capacity, so additional stabilization is needed to keep loads from causing excessive settlement or movement. Soft soil anchors are installed when the CBR falls below 15 to enhance restraint and transfer load more reliably into the ground. Once the soil is stronger (CBR in the 15–25 range or above 30), the natural bearing capacity is typically sufficient, so soft soil anchors are not ordinarily required. “Not specified” offers no concrete criterion, whereas the low end threshold provides a clear rule of when such anchors are needed.