Abstract: Replacement drainage structures and methods for replacing drainage structures are disclosed. An example method includes driving a plurality of sections of a replacement drainage structure around a buried drainage structure to be replaced. At least a portion of the drainage structure to be replaced is positioned within the interior of a section of the replacement drainage structure. Portions of the drainage structure to be replaced are removed.

Abstract: A drilling fluid composition for horizontal directional drilling is a flowable aqueous slurry of biodegradable, non-toxic, preferably edible plant particles. The particle size of the plant-derived particles depends on the drill bit used. The particles should be small enough not to clog the fluid jet orifices in normal use. The slurry is pumped through to the drill bit in a warm or preferably hot state, e.g. 80-100° C. After ejection, the slurry cools rapidly, causing solidification and creating a lining on the tunnel wall.

Abstract: A drilling fluid composition for horizontal directional drilling is a flowable aqueous slurry of biodegradable, non-toxic, preferably edible plant particles. The particle size of the plant-derived particles depends on the drill bit used. The particles should be small enough not to clog the fluid jet orifices in normal use. The slurry is pumped through to the drill bit in a warm or preferably hot state, e.g. 80-100° C. After ejection, the slurry cools rapidly, causing solidification and creating a lining on the tunnel wall.

Abstract: Replacement drainage structures and methods for replacing drainage structures are disclosed. An example method includes driving a plurality of sections of a replacement drainage structure around a buried drainage structure to be replaced. At least a portion of the drainage structure to be replaced is positioned within the interior of a section of the replacement drainage structure. Portions of the drainage structure to be replaced are removed.

Abstract: A wick assembly for installation under a roadway according to the invention includes a perforated drain pipe, an inner sheet of a wicking fabric disposed on the perforated drain pipe in a manner effective to cover the perforations therein, an outer sheet of a wicking fabric, and a layer of filter aggregates confined between the inner and outer wicking fabric sheets to form a wick drain in combination with the perforated drain pipe. Water passes through the sheets and filter aggregates in order to enter the perforated drain pipe through the perforations therein. The wick drain may be disposed inside an outer pipe with the outer fabric sheet in slidable contact with the inner periphery of the pipe casing. The outer pipe casing serves to protect the wick drain during installation and is later removed once the wick drain is in position.

Abstract: Replacement drainage structures and methods for replacing drainage structures are disclosed. An example method includes driving a plurality of sections of a replacement drainage structure around a buried drainage structure to be replaced. At least a portion of the drainage structure to be replaced is positioned within the interior of a section of the replacement drainage structure. Portions of the drainage structure to be replaced are removed.

Abstract: A wick assembly for installation under a roadway according to the invention includes a perforated drain pipe, an inner sheet of a wicking fabric disposed on the perforated drain pipe in a manner effective to cover the perforations therein, an outer sheet of a wicking fabric, and a layer of filter aggregates confined between the inner and outer wicking fabric sheets to form a wick drain in combination with the perforated drain pipe. Water passes through the sheets and filter aggregates in order to enter the perforated drain pipe through the perforations therein. The wick drain may be disposed inside an outer pipe with the outer fabric sheet in slidable contact with the inner periphery of the pipe casing. The outer pipe casing serves to protect the wick drain during installation and is later removed once the wick drain is in position.

Abstract: A tool for cleaning a drainage structure comprises a rod having a center longitudinal axis, a barrel housing having a proximal opening and a distal opening, the barrel housing having a center longitudinal axis and coupled coaxially to the rod, the barrel housing having an outside dimension that can be accommodated within the drainage structure, the distal opening of the barrel housing having a sinusoidal tearing contour. The tool further comprises a plurality of cutting implements radially coupled to and between the rod and the barrel housing, the cutting implements having a distal cutting edge and being angularly oriented to facilitate sweeping debris in a selected direction, and the barrel housing and cutting implements operable to rotate about the center longitudinal axis of the rod to dislodge and loosen debris inside the drainage structure.

Abstract: A wick assembly for installation under a roadway according to the invention includes a perforated drain pipe, an inner sheet of a wicking fabric disposed on the perforated drain pipe in a manner effective to cover the perforations therein, an outer sheet of a wicking fabric, and a layer of filter aggregates confined between the inner and outer wicking fabric sheets to form a wick drain in combination with the perforated drain pipe. Water passes through the sheets and filter aggregates in order to enter the perforated drain pipe through the perforations therein. The wick drain may be disposed inside an outer pipe with the outer fabric sheet in slidable contact with the inner periphery of the pipe casing. The outer pipe casing serves to protect the wick drain during installation and is later removed once the wick drain is in position.

Abstract: A tool for cleaning a drainage structure comprises a rod having a center longitudinal axis, a barrel housing having a proximal opening and a distal opening, the barrel housing having a center longitudinal axis and coupled coaxially to the rod, the barrel housing having an outside dimension that can be accommodated within the drainage structure, the distal opening of the barrel housing having a sinusoidal tearing contour. The tool further comprises a plurality of cutting implements radially coupled to and between the rod and the barrel housing, the cutting implements having a distal cutting edge and being angularly oriented to facilitate sweeping debris in a selected direction, and the barrel housing and cutting implements operable to rotate about the center longitudinal axis of the rod to dislodge and loosen debris inside the drainage structure.

Abstract: A wick assembly for installation under a roadway according to the invention includes a perforated drain pipe, an inner sheet of a wicking fabric disposed on the perforated drain pipe in a manner effective to cover the perforations therein, an outer sheet of a wicking fabric, and a layer of filter aggregates confined between the inner and outer wicking fabric sheets to form a wick drain in combination with the perforated drain pipe. Water passes through the sheets and filter aggregates in order to enter the perforated drain pipe through the perforations therein. The wick drain may be disposed inside an outer pipe with the outer fabric sheet in slidable contact with the inner periphery of the pipe casing. The outer pipe casing serves to protect the wick drain during installation and is later removed once the wick drain is in position.