ACL Project List


One of the most important findings from the study is the need to understand how water moves through a masonry wall system, especially as it is influenced by grade, repairs, orientation, and associated fill.


The moisture level graph shows that the increase in soil moisture level coincides with the melting of the standing snow in spring as temperature rises.  Moisture uptake by the wall from the adjacent soil fill and ground occurs for an extended period of time, especially as snow drift melt, and ultimately may be more damaging to the overall stability of the wall than moisture entering from the top through occasional precipitation events. 


The high humidity level inside the sealed environment of the cap shows the need for ventilation to lower the moisture level inside the caps.  Both soil cap gravel layer and hard cap experienced very high relative humidity throughout the testing period, due to the lack of drying within the spaces.  The use of mortar or geosynthetics should be used with the clear understanding of water movement as these materials can trap water in unwanted spaces.  Creating a functioning outlet for water in both liquid and vapor phases is critical for designing effective caps.


The soil layer was resilient in handling moisture.  Soil depth, its immediate surroundings, and orientation all influence the amount of water soil can hold.  Despite the same soil depth of the probes located in Room 13, one recorded a higher moisture level than the other due to the close proximity to the water path.  In addition, while both caps received the same precipitation, those located in Room 13 showed much lower moisture content compared to the one in Room 28.  This is likely to be the result of different orientation and the presence of geosynthetics.

Cap design diagram