GB2101656A

GB2101656A - Trenchless pipe laying

Info

Publication number: GB2101656A
Application number: GB08121892A
Authority: GB
Inventors: Alexandr Dmitrievich Kostylev; Anatoly Yakovlevich Tishkov; Vladimir Alexan Grigoraschenko; Khaim Berkovich Tkach; Vladimir Pavlovich Gileta; Valery Afanasievich Kozlov
Original assignee: Trest Orgtekhstroi Glavnovosibirskstroya Minstroya Ssr; Institut Gornogo dela Sibirskogo Otdelenia Akademii Nauk SSSR; TREST ORGTEKHSTROI GLAVNOVOSIB
Current assignee: Trest Orgtekhstroi Glavnovosibirskstroya Minstroya Ssr; Institut Gornogo dela Sibirskogo Otdelenia Akademii Nauk SSSR; TREST ORGTEKHSTROI GLAVNOVOSIB
Priority date: 1981-07-15
Filing date: 1981-07-15
Publication date: 1983-01-19
Also published as: GB2101656B

Abstract

A pipe 1 is driven into earth by a pneumatic hammer 4 which applies a driving force to the pipe 1 lengthwise. The pipe 1, where it enters earth, is acted upon by a vibration load perpendicular to the pipe axis. Spoil 8 is discharged from the pipe 1. <IMAGE>

Description

SPECIFICATION Trenchless pipe laying The present invention relates to methods of trenchless pipe laying and is particularly intended for use where open laying of underground pipe lines may cause damage to structures on the ground, for example where pipelines intersect roads.

The invention provides a method of trenchless pipe laying in which a pipe is driven into earth by a pneumatic hammer or other means which applies a driving force to the pipe lengthwise thereof and spoil is removed from the pipe, and in which during the process of driving-in, the pipe is acted upon by vibration load applied to the pipe transversely (preferably perpendicular) to the axis thereof where it enters earth.

It is desirable for the magnitude of the vibration load to be varied, more particularly increased, as the pipe is driven in.

The method of trenchless pipe laying according to the present invention provides for efficient removal of spoil from pipes, even from those of substantial length, during the process of pipe driving-in. The combination of the disturbances acting upon the pipe due to the application of the driving force and the vibration increases the rate of conveying spoil from the pipe, i.e. decreases power consumption and increases the working capacity of the process.

The invention will be described further, by way of example, with reference to the accompanying drawings, wherein: Figure 1 depicts the initial stage of a pipe driving operation; Figure 2 depicts the same operation as in Figure 1, the pipe being already driven into the earth to a major extent and the source of vibration load being now nearer the tailend of the pipe; and Figure 3 is a section on line Ill-Ill of Figure 1.

A pipe 1 with its head end open, is placed in a pit 2. In the other end of the pipe 1 is rigidly secured a sleeve 3 with a pneumatic hammer 4.

Radial ribs 5 are provided between the sleeve 3 and the pipe 1. The sleeve 3, the pneumatic hammer 4, and the ribs 5 are rigidly secured in the pipe 1 by means of a wedging fit which is obtained by providing the said elements with taper surfaces whose angle of taper is less than the angle of metal-to-metal friction. A vibrator 6 is installed on the pipe 1 where it enters the earth, the vibrator being mounted on a sleeve 7 which is movably mounted on the pipe 1. The vibrator 6 can be of any design known in the art, preferably a pneumatic vibrator.

When the pneumatic hammer 4 operates, it produces impact impulses lengthwise of the pipe 1, whereby the pipe 1 is driven into the earth, spoil 8 entering the pipe 1. The vibrator 6 comes into action simultaneously with the pneumatic hammer 4 and creates forces acting upon the pipe 1 perpendicular to its axis, owing to which transverse vibrations spread along the pipe 1.

Under the action of these vibrations the spoil 8 is transferred along the pipe 1 towards the pipe end and is discharged through the spaces between the ribs 5 (Figure 3). As the pipe 1 (Figure 2) is driven into the earth, the vibrator 6 mounted on the sleeve 7 is displaced with respect to the end of the pipe 1, always staying at the point of entry of the pipe 1 into earth. This positioning of the vibrator 6 makes it possible to most effectively act upon the pipe 1, especially the part already driven into earth. The disturbance force of the vibrator 6 is varied as the pipe 1 is driven in. the minimum force is used when a small part of the pipe 1 is driven in; further, the force of the vibrator 6 is increased.

The pipe laying method described above provides for decreasing the power consumption of the process by virtue of regulating both the disturbance force of the vibrator 6 and the impact impulse produced by the pneumatic hammer 4.

Thus, the rate of conveying spoil in laying the pipe 1 in soft ground can be increased by decreasing the impact impulse and increasing the disturbance force. In compact ground, it is advantageous to increase the impact impulse, i.e.

to increase the rate of pipe driving-in.

Example A pipe of 426mm outside diameter was driven into solid ground by means of a pneumatic hammer and at the same time the pipe, where it entered the earth, was acted upon by a vibration load applied perpendicular to the pipe axis. The characteristics of the vibration load were as follows: disturbance force 2t, frequency 24Hz. As the pipe was driven in by the impacts of the pneumatic hammer, the vibrator was moved along the p;pe toward the end where the pneumatic hammer was installed. The combination of the disturbances acting upon the pipe due to the operation of the pneumatic hammer and the vibrator resulted in efficient discharge of spoil from the pipe.

Claims

1. A method of trenchless pipe laying in which a pipe is driven into earth by applying a driving force to the pipe lengthwise, the pipe being acted upon by a vibration load applied to the pipe transversely to its axis where it enters the earth, and spoil being removed from the pipe.

2. A method as claimed in claim 1, in which the vibration load is increased or otherwise varied as the pipe is driven in.

3. A method as claimed in claim 1 or 2, in which the vibration load is applied by a pneumatic vibrator.

4. A method as claimed in any of claims 1 to 3,

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Trenchless pipe laying The present invention relates to methods of trenchless pipe laying and is particularly intended for use where open laying of underground pipe lines may cause damage to structures on the ground, for example where pipelines intersect roads. The invention provides a method of trenchless pipe laying in which a pipe is driven into earth by a pneumatic hammer or other means which applies a driving force to the pipe lengthwise thereof and spoil is removed from the pipe, and in which during the process of driving-in, the pipe is acted upon by vibration load applied to the pipe transversely (preferably perpendicular) to the axis thereof where it enters earth. It is desirable for the magnitude of the vibration load to be varied, more particularly increased, as the pipe is driven in. The method of trenchless pipe laying according to the present invention provides for efficient removal of spoil from pipes, even from those of substantial length, during the process of pipe driving-in. The combination of the disturbances acting upon the pipe due to the application of the driving force and the vibration increases the rate of conveying spoil from the pipe, i.e. decreases power consumption and increases the working capacity of the process. The invention will be described further, by way of example, with reference to the accompanying drawings, wherein: Figure 1 depicts the initial stage of a pipe driving operation; Figure 2 depicts the same operation as in Figure 1, the pipe being already driven into the earth to a major extent and the source of vibration load being now nearer the tailend of the pipe; and Figure 3 is a section on line Ill-Ill of Figure 1. A pipe 1 with its head end open, is placed in a pit 2. In the other end of the pipe 1 is rigidly secured a sleeve 3 with a pneumatic hammer 4. Radial ribs 5 are provided between the sleeve 3 and the pipe 1. The sleeve 3, the pneumatic hammer 4, and the ribs 5 are rigidly secured in the pipe 1 by means of a wedging fit which is obtained by providing the said elements with taper surfaces whose angle of taper is less than the angle of metal-to-metal friction. A vibrator 6 is installed on the pipe 1 where it enters the earth, the vibrator being mounted on a sleeve 7 which is movably mounted on the pipe 1. The vibrator 6 can be of any design known in the art, preferably a pneumatic vibrator. When the pneumatic hammer 4 operates, it produces impact impulses lengthwise of the pipe 1, whereby the pipe 1 is driven into the earth, spoil 8 entering the pipe 1. The vibrator 6 comes into action simultaneously with the pneumatic hammer 4 and creates forces acting upon the pipe 1 perpendicular to its axis, owing to which transverse vibrations spread along the pipe 1. Under the action of these vibrations the spoil 8 is transferred along the pipe 1 towards the pipe end and is discharged through the spaces between the ribs 5 (Figure 3). As the pipe 1 (Figure 2) is driven into the earth, the vibrator 6 mounted on the sleeve 7 is displaced with respect to the end of the pipe 1, always staying at the point of entry of the pipe 1 into earth. This positioning of the vibrator 6 makes it possible to most effectively act upon the pipe 1, especially the part already driven into earth. The disturbance force of the vibrator 6 is varied as the pipe 1 is driven in. the minimum force is used when a small part of the pipe 1 is driven in; further, the force of the vibrator 6 is increased. The pipe laying method described above provides for decreasing the power consumption of the process by virtue of regulating both the disturbance force of the vibrator 6 and the impact impulse produced by the pneumatic hammer 4. Thus, the rate of conveying spoil in laying the pipe 1 in soft ground can be increased by decreasing the impact impulse and increasing the disturbance force. In compact ground, it is advantageous to increase the impact impulse, i.e. to increase the rate of pipe driving-in. Example A pipe of 426mm outside diameter was driven into solid ground by means of a pneumatic hammer and at the same time the pipe, where it entered the earth, was acted upon by a vibration load applied perpendicular to the pipe axis. The characteristics of the vibration load were as follows: disturbance force 2t, frequency 24Hz. As the pipe was driven in by the impacts of the pneumatic hammer, the vibrator was moved along the p;pe toward the end where the pneumatic hammer was installed. The combination of the disturbances acting upon the pipe due to the operation of the pneumatic hammer and the vibrator resulted in efficient discharge of spoil from the pipe. Claims

4. A method as claimed in any of claims 1 to 3, in which the driving force is applied by a pneumatic hammer.

5. A method of trenchless pipe laying substantially as described with reference to the accompanying drawings.