Ground freezing for support of open excavations

A practical discussion of critical factors for designing and constructing temporary frozen earth ground support and groundwater control systems for large open excavations is reported. Many construction projects require extensive subsurface work which can best be completed in a large open excavation, shaped to accommodate the subsurface structure. Frequently, lateral ground support of adjoining property and groundwater control within the excavation are major problems for completion of subsurface work. Construction ground freezing has now become an economically competitive solution for many such applications, particularly in bad ground.

The general experience gained from completing ground freezing for numerous open excavation projects over the past ten years is reported to assist in the evaluation, design and construction of future projects. The principal emphasis of this report is the practical construction and field instrumentation procedures necessary successfully to complete ground freezing for a project. Examples from past projects ranging from large nuclear power plants to small sewerage pumping stations are employed to emphasize important points.