EP-4739877-A1 - STEERING HEAD FOR PIPE RAMMING/HAMMER BORING INSTALLATIONS

Abstract

A steering head for a pipe ramming hammer bore construction system, configured to allows passage of soil through the center of the steering head while maintaining the ability to change the bore alignment through the use of inflatable bags which are underlying and adjacent to a portion of a shell member which extends radially outward from the steering head upon inflatation of the inflatable bag. The inflatable bags may be inflated by inflation media supply lines which extend from the bore pit to the steering head and deflated by release of the inflation media. The media flow to the inflatable bags may be controlled by media valves which may be located in the steering head or, alternatively, at a different location, such as in the bore pit. The remote nature of the system eliminates the need for frequent removal of the pneumatic hammer, confined space entry, and manual corrections performed inside the casing.

Inventors

• ORNDORFF, AARON
• SHERRELL, BRIAN

Assignees

• PLG TECHNOLOGIES, INC.

Dates

Publication Date

20260513

Application Date

20240708

Claims (17)

1. 1. A steering head for a pipe ramming hammer bore system utilized for boring a borehole, the steering head comprising: a casing member having an inside diameter, an exterior surface, an interior, a lead end and a tail end, wherein the lead end of the casing member is configured to be utilized in a boring operation; a pocket section defined on the exterior surface; an inflatable bag disposed within the pocket section; and a shell member disposed on the casing member thereby enclosing the pocket section and the inflatable bag, wherein at least a portion of the shell member is configured to extend radially outward upon an inflation of the inflatable bag.
2. 2. The steering head of claim 1 wherein the inflatable bag is configured to cycle between an inflated state and a deflated state.
3. 3. The steering head of claim 2 wherein a hose is connected to the inflatable bag, the hose providing a conduit for delivery of an inflation media to the inflatable bag.
4. 4. The steering head of claim 3 wherein the hose provides a conduit for release of the inflation media from the inflatable bag.
5. 5. The steering head of claim 3 wherein the inflation media comprises air.
6. 6. The steering head of claim 1 wherein the casing member comprises a plurality of pocket sections, each pocket section disposed at a different circumferential position of the exterior surface.
7. 7. The steering head of claim 6 wherein the casing member comprises a rear section, a middle section, and a front section, wherein the pocket sections are disposed within the middle section.
8. 8. The steering head of claim 7 wherein the middle section comprises a forward end and an aft end wherein the internal diameter of the middle section decreases from a first diameter at the forward end to a smaller diameter at the aft end.
9. 9. The steering head of claim 7 wherein a bulkhead member is disposed between the rear section and the middle section.
10. 10. The steering head of claim 9 wherein the bulkhead member comprises a plurality of hose penetrations through which a plurality of hoses extend through the hose penetrations to the pocket sections.
11. 11. The steering head of claim 1 wherein the shell member comprises a window at a position overlying and adjacent to the inflatable bag, wherein a steering plate has been disposed over the window, wherein the steering plate is configured to pivot outwardly upon inflation of the inflatable bag.
12. 12. The steering head of claim 10 wherein the steering plate is attached to the shell member by a welded flat bar.
13. 13. The steering head of claim 1 wherein the shell member comprises a plurality of overlapping plate members, wherein at least a portion of the overlapping plate members extend radially outward upon the inflation of the inflatable bag.
14. 14. The steering head of claim 12 wherein the plurality of overlapping plate members are disposed in a parallel pleated configuration.
15. 15. The steering head of claim 1 wherein the shell member comprises a thinwalled deformable plate, wherein at least a portion of the thin-walled deformable plate extends radially outward upon inflation of the inflatable bag.
16. 16. The steering head of claim 14 wherein the thin-walled deformable plate is configured as cylindrical shell having a first edge of the thin-walled deformable plate overlapping a second edge of the thin-walled deformable plate.
17. 17. The steering head of claim 1 wherein the inflatable bag is restrained from lateral expansion by a strut bar.

Description

STEERING HEAD FOR PIPE RAMMING/HAMMER BORING INSTALLATIONS INVENTORS: AARON ORNDORFF BRIAN SHERRELL DOCKET NO.: 2024-001 BACKGROUND OF THE INVENTION [0001] The present invention generally relates to pipe ramming (also known as hammer boring) utilized in trenchless construction operations. As opposed to open cut construction, in trenchless construction line-of-sight locating of the boring or trenchless apparatus is a costly and time-consuming process. While trenchless construction methods are, by themselves, more expensive than open cut construction, trenchless construction provides a number of benefits because it avoids a number of costs associated with open cut construction. These costs include pavement removal and replacement, dewatering, surface restoration, right-of-way, or utility acquisition, public inconvenience, lost business revenue arising from road closure or obstruction, reduction of noise and dust, tree removal, etc. In other cases, such as river crossings, lakes, wetlands, etc., trenchless construction provides the only available construction method. [0002] In many cases, the soil type, distance of the required bore, type of utilities to be installed in the casing, and regulations from an authority having jurisdiction over the project will dictate the construction methods of casing installation. Certain types of soil conditions make conventional jack-and-boring, auger boring, or the like, unfeasible. These conditions include flowing sand, marshy/high ground water conditions, and soils comprising unpredictable quantities and sizes of cobbles. In these cases, the method of construction that is generally preferred is a pipe ramming operation. [0003] In the pipe ramming method of horizontal casing installation, a high- volume compressor powers a pneumatic hammer which is placed at the rear of a first section of casing. The pneumatic hammer and its support structure and the first casing section are typically placed in a generally horizontal orientation at the bottom of a bore pit, with the front of the first section of casing facing an earth wall through which the bore will extend. The front of the first section of casing will have a "shoe" which is configured to encounter and penetrate the earth as the pneumatic hammer applies blows at the opposite end of the casing. [0004] Upon application of a high flow rate of high-pressure air to the pneumatic hammer, a steel slug moves back and forth, causing the hammer to strike the rear of the casing at approximately 2-3 cycles per second. This impact slowly drives the casing horizontally through the ground. Once the casing has been driven a certain length into the ground, the pneumatic hammer is removed from the casing and an additional section of casing are welded to the end of the casing in the bore pit. The hammer is placed back in position and the operation continues, with sections of casing added as the bore proceeds. When the leading edge of the casing penetrates through the ground to a receiving pit located at the opposite end of the bore, the hammer is removed from the bore pit and the soil inside the casing is cleared out to complete the installation, with the casing typically cleaned out with a traditional auger or by using compressed air to push a cleaning pig through the casing. [0005] The pipe ramming bore method has certain advantages, including the ability to break apart cobbles from the impact force of the hammer. Without rotating augers disturbing the native soil, there is less chance of a cobble getting into a bind with the cutting head or augers thereby causing damage. In addition, spoils are not actively excavated away from the leading edge of the casing as is done with auger bore installations. This feature results in a substantial dirt plug being maintained inside the casing toward the front. The dirt plug prevents flowing sugar sand and/or muddy/marshy soil from flowing into the casing and creating a void above the casing, which is a major concern for auger bore installations. [0006] Among the disadvantages of the pipe ramming method is its unpredictability. Pipe ramming operations are essentially conducted using a "point and shoot" approach because the known operations provide no ability to steer the bore. As a result, if the casing encounters a large cobble or soil stratification, the bore may be deviated from its intended line and grade. There have been documented cases of such bores surfacing in the middle of active roadways and railroad tracks because the bore took a drastic, upward trajectory. Resolving this unpredictability has typically involved installing a much larger casing than required for the utility. This is especially true for sewer and other gravity fed pipelines that must be installed on a slope. If a casing much larger than required for the intended utility is installed there is less chance that the design grade of the utility will be compromised. [0007] The steering heads known for use in auger bore operations