This invention relates to a method for insulating sub-soil comprising mechanically destructuring the sub-soil, injecting an insulating material into the destructured sub-soil, and mixing the sub-soil and the insulating material. The thermal conductivity of the insulating material is strictly lower than the thermal conductivity of the sub-soil.

Extensible shells and related methods for constructing a support pier are disclosed. An extensible shell can define an interior for holding granular construction material and define a first opening at a first end for receiving the granular construction material into the interior and a second opening at a second end. The extensible shell can be flexible such that the shell expands when granular construction material is compacted in the interior of the shell. A method may include positioning the extensible shell in the ground and filling at least a portion of the interior of the shell with the granular construction material. The granular construction material may be compacted in the interior of the extensible shell to form a support pier.

A method for reinforcing an aggregate pier. The method includes inserting a conical-head pipe into the aggregate pier, injecting grout into the aggregate pier by injecting the grout into the inner chamber of the hollow rod, driving the conical-head pipe into a soil under the aggregate pier by driving a secondary pipe into the aggregate pier and pushing the conical-head pipe toward the soil under the aggregate pier by utilizing the secondary pipe, filling the secondary pipe with grout, and inserting a reinforcement bar into the secondary pipe and the hollow rod. This method reinforces an aggregate pier against excess tensional and compressional loads of a concrete foundation.