Ground freezing is a technique used in construction and engineering to stabilize soil and create a solid working environment. By lowering the temperature of the ground, water in the soil freezes, turning it into a solid mass. This process helps prevent soil movement and provides support for structures during excavation or tunneling. The method involves circulating a refrigerant through pipes buried in the ground, which cools the surrounding soil. Ground freezing is particularly useful in areas with high groundwater levels or unstable soil conditions, allowing for safer and more efficient construction projects, such as tunnels and foundations.