GB2079345A - Apparatus for treating poor subsoil - Google Patents

Abstract

In an apparatus for treating poor subsoil, a setting agent is stored in a working vessel 1, and a scaffold 3 is carried on the working vessel so that a blender 4 is suspended in a vertically movable manner. The blender has its agitating shafts 10 attached to supporting cylinders 9 and equipped at their lower portions with setting agent feeding devices for injecting the setting agent so that the poor subsoil and the setting agent may be blended and subjected to the setting treatment by the actions of the blades which are attached to the agitating shafts. There are further carried on the working vessel a positioning surveying device, a scavenger of the poor soil in the supporting cylinders, and a circulating circuit of a setting agent feeding hose. <IMAGE>

Description

SPECIFICATION Apparatus for treating poor subsoil The present invention relates to an apparatus for installation on a working vessel for treating poor subsoil.

It is known to set poor subsoil to produce artificial subsoil. The poor subsoil has a far lower moisture content than sludge so that it is more suitable for such a setting treatment. When, however, the poor subsoil extends deeply, the blend of the soft soil and the setting agent has been insufficient to effect a setting treatment of sufficient strength. Moreover, if the setting agent is injected by the use of a treating apparatus into soft soil at the sea bottom so that they may be blended to produce a continuous solid wall, the treating apparatus has to be consecutively shifted from place to place for the setting treatment.

Forthis purpose, there has been adopted, either a method in which a reference post is piaced in the vicinity of the working area of the sea and in which the distance and direction of a working vessel from the reference post are measured by means of a measuring tape or by a transmission so that the measured results are transmitted by wireless to the quarter master of the vessel, or a method in which a gyroscope or compass for navigation is used. Therefore, a plurality of persons is required for the measurements, and the observation error has been large because the works on the sea are accomplished manually.

It is an object of the present invention to provide a treating apparatus for feeding a setting agent to poor subsoil and for blending them by means of a agitating shaft thereby to produce subsoil having excellent properties.

A second object of the present invention is to make it possible to anchor a working vessel carrying the treating apparatus reliably and easily in position.

Athird object of the present invention is to hold a group of agitating shafts aligned, by means of a cylindrical supporting member, while clearing the cylindrical supporting member of the soft soil, thereby not to leave any soft soil untreated.

A fourth object of the present invention is to prevent the setting agent, which is fed from an agitator to the tip of the agitating shaft through a conduit, from becoming solid due to termination of the fluidity of the setting agent by providing a return hose separately of said conduit thereby to form a circulat- ing passage for the setting agent.

According to the present invention there is provided a poor subsoil treating apparatus for a working vessel having facilities for storing a setting agent and a control device for a setting treatment, which apparatus includes a blender for suspension from a scaffold on a said working vessel in a vertically movable manner; a plurality of agitating shafts adapted to be driven by a drive unit of said blender such that adjacent shafts are turned in opposite directions; a plurality of agitating blades attached to the lower portions of said agitating shafts and constituting a blending portion for blending the poor subsoil and the setting agent; and setting agent feeding means for feeding the setting agent from a setting agent supply source to the blending portion of said agitating shafts.

Embodiments of the apparatus will now be described, by way of example only, by reference to the accompanying drawings in which: Fig. 1 is an explanatory view showing the manner in which a treating apparatus according to the present invention and carried on a working vessel is used; Fig. 2A is a side elevation showing the manner in which the blender of the treating apparatus is held; Figs. 2B and 2C are sections taken along lines A-A and B-B of Fig. 2A, respectively; Fig. 3A is a side elevation showing the manner in which a blender of a treating apparatus different from that of Fig. 2A is held; Figs. 3B and 3B are sections taken along lines C-C and D-D of Fig. 3A, respectively; Fig. 4A is a side elevation showing an agitating portion of a said treating apparatus; Fig. 4B is a section taken along line E-E of Fig. 4A;; Fig. 4C is an explanatory view showing the directions of rotation of the agitating shafts of Fig. 4A; Fig. 5 is an explanatory view showing the arrangement of a measuring device to be used for positioning the working vessel; Fig. 6 is an illustration explaining the principles for positioning the working vessel; Figs. 7A, 7B, 7C and 7D are front elevations of the agitating shaft and shows four embodiments for clearing an agitating shaft holding cylinder of soft soil.

Fig. 8 is an illustration of the feeding of the setting agent to the tip of the agitating shadt; and Figs. 9A and 9B are diagramatic views showing the respective operating conditions of a change-over valve for circulating the setting agent.

Figs. 1 to 4, there is shown treating apparatus for poor subsoil which apparatus is carried on a working vessel 1. This vessel 1 is generally rectangular in shape and is provided at its centre with a vertical through hole 2. A scaffold 3 stands on the working vessel 1 in such a manner that it can traverse the through hole 2. At the side of the scaffold 3, there is arranged a blender 4 for improving the subsoil, the upper end of which is held by a wire or rope suspended by a pulley5 at the top of the scaffold 3. The wire is pulled by a winch, which is placed on the base of the scaffold 3, so that the blender 4 can be moved up and down. In order to prevent the blender 4 from swinging while holding its vertical position, upright guide rails 6 are provided, as shown in Figs.

2A to 2C, and sliding ears 7 are attached to the both sides of the blender 4 such that they can slide in said guide rails 6. Although not shown in the drawings, the guide rails 6 are made movable up and down with respect to the scaffold 3 in the same manner as is the blender4.

In an alternative, the holding structure of the blender 4 may be made in such a manner as is shown in Figs. 3Ato 3C. In this modification, specifically, a sliding ear 7, which is attached to the side of the blender 4 facing the scaffold 3, is guided to slide in a single guide rail 6 which is attached to the scaffold 3.

Reverting to Fig. 1, there are also carried on the working vessel 1 a prime mover, a hydraulic device and other equipment for driving the blender 4. There are further carried a pump for pumping a setting agent into the blender 4, a plant Pu for preparing the setting agent and a silo Safor storing a material for the setting agent. By means of a control device in a control room 8 which is also carried on the working vessel 1, the pump and the hydraulic device are operable so that the blender 4 may be moved up and down or stopped.

A ballast tank is also carried on the working vessel 1 so thatthe vessel 1 can always be held in a horizontal position.

Turning to Figs. 4A, 4B and 4C, in the blender 4, agitating shafts 10 are supported through bearings 11 upon the respective quadrants of a cylindrical supporting cylinder 9, thus constituting four agitating shaft portions. These four shaft portions are coupled into such two agitating portions as form a blending part of the present invention. In other words, two groups of the supporting cylinders 9 equipped with the agitating shafts 10 are coupled by means of a horizontal auxiliary member thereby to constitute the blender of the present invention. The upper end of each agitating shaft 10 is connected to a reduction gear mechanism 13, which is driven by a drive motor 12, and is held thereabove by the suspending wire through a supporting frame.The agitating shaft 10 thus held has its lower end portion extending downward from the lower end of the corresponding supporting cylinder9 and is equipped with agitating blades 14. Here, the adjacent agitating shafts 10 are turned in the opposite directions so that little or no torsion is exerted upon the supporting cylinder9 of the adjacent shafts 10. Along the side wall of the supporting cylinder 9, there is arranged a setting agent feeding pipe 15, which has its upper end communicating with the plant Pu through a setting agent feeding hose, a grout pump, etc., the lower end of the pipe being located in the vicinity of the agitating blades 14. As an alternative, the agitating sahfts 10 may be formed into such a cylindrical shape as to provide the passagesforthe setting agent in place of the feeding pipes 15.

To use the blender 4 having the construction thus far described, the agitating shafts 10 are forced, while being turned, into a poor subsoil layer by the operations of the pump or the hydraulic device. After that, if the setting agent is fed through its feeding pipes 15whilethe agitating shafts 10 are bingturned and pulled up, the setting agent is sufficiently blended with the poor subsoil, thus effecting the setting treatments.

However, the working vessel has to be anchored accurately at a preset position where the subsoil is to be improved. The surveying operation of the preset position is performed by a position surveying device which is also carried on the working vessel. The construction of a surveying device according to the present invention will now be described with reference to Figs. 1 and 5.

The device for surveying the position of the working vessel is composed of three optical range finders 16a, 16b and 16c, which are arranged at three positions of the working vessel 1 and a computer 17 which is disposed in the control room 8. The optical range finders 16a, 16b and 16c are of automatic tracking type and are operated by a remote control device 18.

On a reference base 19, there are arranged three reflecting mirrors 20a, 20b and 20c of automatic tracking type, which are spaced at a preset distance.

The three optical range finders 16a, 16b and 16c are so arranged as to measure the distances from the corresponding reflecting mirrors.

The three optical range finders 16a, 16b and 16c thus arranged are connected through respective cabtype cables 21 to the computer 17, which in turn is connected to a display unit 22.

The computing method to be adopted in the position surveying device will now be described with reference to Fig. 6. The positions of the left and right range finders 16a and 16b to be located on the working vessel 1 are designated asA and B, respectively.

Next, the rectangular coordinates of the positionA are assumed to be expressed by (0, 0). Then the position B, which is spaced by a distance d1 from the position A is expressed by (d1, 0), and the position C of the range finder 16c, which is spaced by a distance c from the position B, is expressed by (d1c, 0). If, on the other hand, the position D of the reflector 20a at the reference point is expressed byp, s,!, then the position E of the other reflector 20b, which is spaced by a distance d2 from the reflector 20a, is expressed by (p + d2, s). From these values, the lengths Ii, and l3 of the linesAD, BE and CD can be computed in the following manner.

In the case the working vessel is moved to displace the pointsA and B to pointsA' and B', the displace ments are to be determined. If the pointA' is located at (x1, y1) whereas the point B' is located at (x2, y2), then the lengthes 11', 12' and 13" of the linesA'D, B'E and C'D are surveyed by the optical range finders 16a, 16b and 16c so that they can be computed by the following Equations. Incidentally, the length 13'" and the angles Oi', 7, 62' and E appearing in Fig. 6 are used for the computations.

In Fig. 6: q = d1-d2-p ------------------- (1 d12 hi2 + l3'" -2l1'l3'" cose1' --(2) d2 = l2' + l3'"-2l2'l3'"cos #2' --------- (3) l2'cos = l3'"cos(#2 + #) -------------- (4) c = l3" + l3'"-2l3'"cos&gamma; -------- (5) (d1-c) = l1' + l3"-2l1'l3"cos(#1'-y) --- (6) In the above Equations, since the values c, d1, d2 andp are given and since the lengthes l1',l2' and 13" are surveyed by the range finders, the value q can be determined from Equation (1), and the values 01', y and 13' "can be determined from Equations (2), (5) and (6).

Moreover, the values 02' and E can be determined from Equations (3) and (4), respectively.

Hence: x2 = l2|sin#-q -------------------- (7) y2 = S l2|cos# -------------------- (8) cos#-p/l1 ----------------------- (9) # = #/2 -(#2' +#) ------------------- (10) # =#/2-(# + ss) --------------------- (11) tanss = (d1-p)/S ------------------(12) tan&alpha;=(p/S -------------------(13) &alpha; + ss + # - #=#1' ------------------(14) From the above Equations: x1=p-11( e+) - -----------------(15) y1=S-l2sin(#+#) From these computations, the displaced positions A' (x1, vi) and B' (x,, y,) of the working vessel are determined, whereupon the relative positions are displaced on the coordinates, in which the points A and B are used as the origins, in the display unit 22.

Thus, the position of working vessel 1 can be viewed on the display unit 22.

In the aforementioned blender 4, a device for scavinging any poor soil entering into the supporting cylinder 9 will now be described with reference to Figs. 7A, 7B and 7C. The reason why the supporting cylinder 9 is cleared of the poor soil is to scavenge the poor soil which is left untreated to be set. According to the embodiment shown in Fig. 7A, a hydraulic jack 23 is inserted into the supporting cylinder 9 such that one end thereof is fixed to the upper end of the supporting cylinder 9 whereas and the other end is connected to a rod 24 which extends to the lower end portion of the cylinder 9. There are attached at several positions of the rod 24 blades 25 for up and down movement so that the poor soil in the supporting cylinder 9 is stirred in preparation for its discharge from the cylinder 9 and its subsequent biending with the setting agent outside the supporting cylinder 9.Incidentally, the biades 25 are radially spaced at their outer circumferential edges from the inner wall of the supporting cylinder 9. The extending and contracting operations of the hydraulic jack 23 is accomplished by a hydraulic control device (not shown) which is disposed at an upper portion of the blender 4 or on the working vessel. Thus, the rod 24 is moved up and down under the control of the hydraulic control device.

In the embodiment shown in Fig. 7B, the supporting cylinder9 is provided at its upper portion with a water inlet 26, though which water is suppled, if necessary, under the control of a water supply control device via a hose (un-numbered). Thus, water flowing into the upper portion of the cylinder 9 flows down the poor soil or boosts its pressure so that the poor soil is discharged out of the cylinder 9 until it can be blended with the setting agent. Incidentally, the water acting as a working fluid can be replaced by compressed air.

In the embodiment of Fig. 7C, there is attached to the inner wall of the lower portion of the supporting cylinder 9 a water nozzle 27, which is made operative to inject a water jet upward to reduce or eliminate friction between the poor soil and the inner wall of the cylinder 9. Thus, the poor soil may be discharged out of the supporting cylinder 9. The water supply to the nozzle 27 is controlled by a control device which is preferably disposed at an upper portion of the blender 4 or on the woring vessel. Incidentally, the nozzle 27 is equipped with means for effecting swinging motions of the nozzle 27 along the inner circumferential wall of the supporting cylinder 9.

In the embodiment shown in Fig. 7D, on the other hand, the supporting cylinder 9 has its lower portion formed with a number of holes 28, from which compressed air is injected thorugh a conduit 29 leading from a compressor or the like so that the friction between the poor soil and the inner circumferential wall of the supporting cylinder 9 may be reduced to facilitate the discharge of the poor soil.

Turning now to Fig. 8, a description will be given of a device for feeding the setting agent to the setting agent feeding pipe 15 of the blender 14. The setting agent feeding pipe 15 is connected through a hose with the outlet port of a grout pump 30 which is mounted on the scaffold 3. The grout pump 30 has its inlet port communicating with the outlet port of an agitator 31 which is also mounted on the scaffold 3. The agitator 31 has its inlet port communicating with the outlet port of the plant through a supply hose 33 which is equipped with a grout pump 32 at its mid-portion. The aforementioned agitator 31 is formed with a setting agent-returning outlet port, which has communication through a return hose 34 with a return inlet port positioned at a lower level than the agitator 31 of the plant.

In the setting agent feeding device thus far described, when the feeding pipe 15 is to be suppled with the setting agent e.g., when the poor soil and the setting agent are to be blended while the blender 4 is being pulled out of the poor soil, the grout pump 32 is driven to feed the setting agent from the plant Pu to the agitator storing that agent, and the other grout pump 30 is driven to further feed the setting agent from the agitator 31 to the feeding pipe 15 through the hose. On the contrary, when no setting agent is to be supplied to the feeding pipe 15, the grout pump 32 is driven, while the other grout pump 30 being left de-energized, to supply the setting agent to the agitator 31 from the plant Pu. Then, the return outlet port of the agitator 31 is opened so that the setting agent may be retained to the plant Pu through the return hose 34 due to the water head.

In these ways, when the feeding pipe 15 is supplied with on setting agent, a circulating circuit is constituted by the plant Pu, the supply hose 33, the agitator 31 and the return hose 34. As a result, the setting agent in the supply hose 33 can be prevented from becoming stagnant and accordingly from premature setting. Incidentally, since the passage for the setting agent downstream of the grout pump 30 is positioned substantially upright, the setting agent is prevented from becoming stagnant, thus making the aforementioned circulating passage unnecessary.

In the setting agent feeding device, on the other hand, another embodiment other than the device of Fig. 8 for preventing the setting agent from becoming stagnant and being set in the passage thereof will now be described with reference to Figs. 9A and 9B. According to this embodiment, between the plantPu and the setting agent feeding pipe 15, there is arranged a plurality of setting agent feeding hoses and water feeding hoses, which have their interconnections changed by changeover valve 35 shown in Fig. 9A corresponds to the case in which the setting agent is supplied to the feeding pipe 15 whereas the water is returned. On the other hand, Fig. 9B corresponds to the case in which the setting agent feeding hoses are partially used as return hoses without supplying the setting agent to the feeding pipe 15 so that the setting agent may be returned. Thus, when the setting agent is not supplied to the feeding pipe 15, it is circulated and returned so that it can be prevented from setting in the feeding hoses. Incidentally, the water in these embodiments is supplied and used for rinsing the blender or for discharging the soil in the embodiments in Figs. 7B and 7C.

Claims (13)

1. A poor subsoil treating apparatus for a working vessel having facilities for storing a setting agent and a control device for a setting treatment, which apparatus includes a blender for suspension from a scaffold on a said working vessel in a vertically movable manner; a plurality of agitating shafts adapted to be driven by a drive unit of said blender such that adjacent shafts are turned in opposite directions; a plurality of agitating blades attached to the lower portions of said agitating shafts and constituting a blending portion for blending the poor subsoil and the setting agent; and setting agent feeding means for feeding the setting agent from a setting agent supply source to the blending portion of said agitating shafts.

2. A poor subsoil treating apparatus as set forth in Claim 1, wherein said agitating shafts are supported upon the respective quadrants of a supporting cylinder.

3. A poor subsoil treating apparatus as set forth in Claim 2, wherein a shaft, to which a plurality of soil discharging blades is attached, is inserted into said supporting cylinder and has its upper end connected to a jack which is attached to the base of said blender.

4. Apoorsubsoiltreating apparatus as setforth in claim 2, further comprising a water inlet disposed at an upper portion of said supporting cylinder so that water can be supplied therefrom into the upper portion of said supporting cylinder.

5. A poor subsoil treating apparatus as set forth in Claim 2, further comprising water or air injecting means disposed at a lower portion of said supporting cylinder.

6. A poor subsoil treating apparatus as set forth in any one of the preceding Claims, wherein said agitating shafts are hollow to provide a supply passage for the setting agent.

7. A poor subsoil treating apparatus as set forth in any one of the preceding Claims, carried on a working vessel and including a control room.

8. A poor subsoil treating apparatus as set forth in Claim 7, further comprising three optical range finders carried on said working vessel at spacings from one another, three reflectors arranged on the reference base of the subsoil to be treated, and a computerfor receiving as its inputs the measured distances between the respective optical range finders and the corresponding reflectors thereby to locate said working vessel.

9. A poor subsoil treating apparauts as set forth in Claim 7 or 8 further comprising an agitator communicating with a setting agent feeding pipe and disposed on the scaffold of said working vessel, a setting agent feeding hose providing communication between said agitator and the setting agent supply source on said working vessel and equipped with a grout pump at its midway, and return hose provided in parallel with said setting agent feeding hose for returning the setting agent, whereby then no setting agent is supplied to said feeding pipe the setting agent fed out of said feeding hose is returned through said return hose.

10. A poor subsoil treating apparatus as set forth in Claim 7 or 8, further comprising at least two setting agent feeding hoses for providing communication between a setting agent feeding pipe and the setting agent supply source on said working vessel, a changeover valve disposed generally midway of said setting agent feeding hoses so that the setting agent fed out of a portion of said feeding hoses may be returned through the remaining feeding hoses by means of said changeover valve.

11. A poor subsoil treating apparatus, substantially as hereinbefore described with reference to the accompanying drawings.

12. A working vessel including a poor subsoil treating apparatus substantially as hereinbefore described with reference to the accompanying drawings.

13. The features hereinbefore disclosed, or their equivalents, in any novel selection.