JP2010159545A - Dredging method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dredging method which can efficiently perform work by enhancing a mud content and reducing the number of operations of scooping sediment when dredging is performed at a predetermined depth. <P>SOLUTION: The dredging is performed with a finishing depth t left with respect to a preset dredging depth D by means of a first bucket lifted and lowered via a hanging wire 10a by a winch device 13. After that, a finishing bucket 1, which has a maximum digging depth set smaller than that of the first bucket and has a maximum opening area set larger than that of the first bucket is attached to the hanging wire 10a in place of the first bucket, and finishing digging is performed at the finishing depth t by means of the finishing bucket 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dredging method, and more specifically, a dredging method that improves the mud content and reduces the number of times of scooping up soil when performing dredging at a predetermined depth so that the work can be performed efficiently. It is about.

  A method of dredging with a grab bucket that is lifted and lowered via a suspension wire by a winch device installed on a work ship or the like is widely known (for example, see Patent Document 1). Conventionally, when dredging with a predetermined depth is performed, it is common for one winch apparatus to be dredged using one type of grab bucket without changing the grab bucket from the beginning to the end of the process. there were.

  Therefore, when finishing digging, which is the last step, if the finishing depth is smaller than the maximum digging depth by the bucket, excess moisture is taken into the bucket, so the mud content (the amount of sediment relative to the bucket capacity) Ratio) has become a factor of lowering work efficiency. This excess moisture further lowered the efficiency of transporting dredged soil and the processing efficiency at the sewage treatment plant.

  Moreover, in this method, since the maximum opening area of the bucket is constant, the maximum area where the earth and sand can be scooped at a time does not change. Therefore, in order to improve the work efficiency, it is not possible to reduce the number of times that the soil is picked up in order to dredge the entire target area even though the amount of earth and sand that is picked up at the time of finish digging is small. Was a disadvantageous way.

JP 2005-335834 A

  An object of the present invention is to provide a dredging method capable of performing work efficiently by improving the mud content and reducing the number of times of scrubbing when dredging at a predetermined depth. .

  In order to achieve the above object, the dredging method of the present invention leaves the finishing depth of the finishing digging with respect to the preset dredging depth by the first grab bucket that is lifted and lowered by the winch device through the suspension wire. After dredging, instead of the first grab bucket, a finishing digging grab bucket having a maximum digging depth smaller than this grab bucket and a large maximum opening area is attached to the suspension wire, and this finishing digging grab bucket It is characterized by finishing digging.

  Here, for example, the bucket capacity of the finish digging grab bucket is made the same as the bucket capacity of the first grab bucket. Further, the finish digging grab bucket can be provided with a detachable bucket cover whose capacity can be changed, and finish digging can be performed by attaching this bucket cover according to the finishing depth.

  According to the present invention, the first grab bucket that is lifted and lowered by the winch device through the suspension wire scoops the earth and sand so as to satisfy the bucket capacity, and finish digging to a preset dredging depth. It can be dredged leaving depth. Then, instead of the first grab bucket, a finishing digging grab bucket having a maximum digging depth smaller than this grab bucket and a large maximum opening area is attached to the hanging wire, and finishing digging is performed by this finishing digging grab bucket. Even when the finishing depth is small, as compared with the first grab bucket, excess moisture taken into the bucket is reduced, and a high mud content can be ensured.

  In addition, by using a finish digging grab bucket having a larger maximum opening area, the maximum area where the earth and sand can be scooped at a time is increased. Therefore, it is possible to reduce the number of times that the earth and sand are scooped up when the entire area to be dredged is finished.

  As described above, skillful use of two types of grab buckets having different maximum digging depths and maximum opening areas enables efficient dredging up to a preset dredging depth.

It is a front view which illustrates a finish digging grab bucket. It is a front view which illustrates the state which the grab bucket of FIG. 1 opened fully. It is a side view of FIG. It is a front view which illustrates the state which attached the bucket cover to the grab bucket of FIG. It is a front view which illustrates the 1st grab bucket. FIG. 6 is a front view illustrating a state where the first grab bucket of FIG. 5 is fully opened. FIG. 6 is a side view of FIG. 5. It is explanatory drawing which illustrates the dredging process by the 1st grab bucket of FIG. It is explanatory drawing which illustrates the finishing digging process by the finishing digging grab bucket of FIG. FIG. 6 is an explanatory view illustrating the maximum opening area of the finish-digging grab bucket of FIG. 1 and the first grab bucket of FIG. 5.

  Hereinafter, the dredging method of the present invention will be specifically described based on the embodiments shown in the drawings.

  In the present invention, the first grab bucket 11 illustrated in FIGS. 5 to 7 (hereinafter referred to as the first bucket 11) and the finish digging grab bucket 1 illustrated in FIGS. 1 to 3 (hereinafter referred to as the finish bucket 1). Two types of buckets are used.

  The first bucket 11 has an upper frame 3 connected to a hanging wire 10a, and two arms 5 and 5 are rotatably supported on the upper frame 3 via support shafts 6c. Yes. The respective shells 12 and 12 are rotatably supported on the other end portions of the respective arms 5 and 5 via a support shaft 6b.

  The upper ends of the shells 12 and 12 are rotatably supported by a support shaft 6 a provided on the lower frame 4. The lower frame 4 is moved up and down with respect to the upper frame 3 by an opening / closing wire 10b. Then, when the lower frame 4 is moved downward, the shells 12 and 12 are rotated about the support shafts 6b and 6b, and are opened as illustrated in FIG.

  When the lower frame 4 moved downward is moved upward by the opening / closing wire 10b, the respective shells 12 and 12 are rotated around the support shafts 6b and 6b, and the portions facing each other are brought into contact with each other in FIG. As illustrated, a closed state is formed and a sealed space is formed. The volume of this sealed space becomes the bucket capacity. The bucket capacity is set near the upper limit of the capability of the winch device 13 in order to improve the working efficiency.

  Thus, earth and sand are taken into the sealed space formed by the pair of shells 12 and 12. It is preferable to provide a seal member that ensures hermeticity at the mutually opposing portions of the pair of shells 12, 12.

  As illustrated in FIG. 7, the pair of shells 12 and 12 have a width W2 and a maximum digging depth (bucket depth) d2.

  Moreover, the wall surface of each shell 12 and 12 is provided with the opening-and-closing door 9b which opens and closes the through-hole 9a formed in this wall surface. When dropping the first bucket 11 to the bottom of the water with the pair of shells 12 and 12 open, the opening / closing door 9b is opened and water passes through the through hole 9a, so that smooth dropping is possible. Further, when the pair of shells 12 and 12 are closed and pulled up on the water, the open / close door 9b is closed to prevent the earth and sand taken in from leaking to the outside.

  Since the basic structure of the finishing bucket 1 is the same as that of the first bucket 11, only the differences will be described. The finishing bucket 1 has a maximum digging depth smaller than that of the first bucket 11 and a maximum opening area. As illustrated in FIG. 3, the width W1 of the pair of shells 2 and 2 is wider (W1> W2) than the width W2 of the pair of shells 12 and 12 of the first bucket 11. Further, the maximum digging depth (bucket depth d1) is smaller than the maximum digging depth (bucket depth d2) of the first bucket 11 (d1 <d2).

  A fixed angle 8 is provided inside each shell 2, 2. As illustrated in FIG. 4, the bucket cover 7 can be attached to and detached from the fixed angle 8. The bucket capacity can be changed by attaching the bucket cover 7 to the fixed angle 8. The fixed angle 8 can also be provided at a plurality of different positions (up and down positions). Similarly, the bucket cover 7 can be detachably attached to the first bucket 11 to change the bucket capacity.

  As illustrated in FIG. 8, a crane is provided on the work boat 14, and the suspension wire 10 a is wound and fed by a winch device 13 of the crane. A first bucket 11 (upper frame 3) is attached to the suspension wire 10a.

  First, the first bucket 11 is used for wrinkling while leaving a finishing depth t with respect to a preset wrinkle depth D. The finishing depth t is smaller than the maximum digging depth of the first bucket 11. Accordingly, if the first bucket 11 is used for normal dredging, a large amount of excess water is taken up.

  Therefore, after the ridge leaving the finishing depth t, the finishing bucket 1 is attached to the hanging wire 10a instead of the first bucket 11 as illustrated in FIG. Then, the finishing digging of the remaining finishing depth t is performed by the finishing bucket 1.

  Since the finishing bucket 1 has a smaller maximum digging depth than the first bucket 11 as described above, it does not take in excess water compared to the case where the first bucket 11 performs normal dredging. Therefore, the mud content at the time of dredging is increased, and the working efficiency can be improved. Since the mud content is high (because the water content is low), it is possible to improve the transport efficiency of drowned sediment and the treatment efficiency at the sediment treatment plant.

  Further, as illustrated in FIG. 10, the maximum opening area S1 of the finishing bucket 1 is larger than the maximum opening area S2 of the first bucket 11, so that the maximum area where the earth and sand can be scooped at a time becomes large. Therefore, it is possible to reduce the number of times that the earth and sand are scooped up when finishing the entire region S to be dredged.

  In this way, the work efficiency is reduced to a preset dredging depth D by using two types of grab buckets (first bucket 11 and finishing bucket 1) having different maximum digging depths and maximum opening areas sequentially. Can be tricked well.

  The bucket capacity of the finishing bucket 1 may be 90% to 110% of the bucket capacity of the first bucket or the same as the bucket capacity of the first bucket 11 as long as the upper limit of the capacity of the winch device 13 is not exceeded. As a result, the ability of the winch device 13 can be utilized to the maximum without wasting it.

  Depending on the finishing depth t, finishing digging can be performed by attaching the bucket cover 7 to the finishing bucket 1. That is, the bucket cover 7 adjusts the bucket capacity of the finishing bucket 1 so as to match the finishing depth t, and performs dredging.

  Specifically, a plurality of types of bucket covers 7 having different vertical cross-sectional areas (different vertical protrusion amounts) are prepared, and one type of bucket cover 7 selected from these is used as the fixed angle 8 of each shell 2 and 2. Install and adjust the bucket capacity. Alternatively, by using one type of bucket cover 7, the bucket cover 7 is attached to the fixed angle 8 at one position selected from a plurality of fixed angles 8 provided at the respective shells 2 and 2 at different positions (vertical positions). To adjust the bucket capacity.

  In the above embodiment, the first bucket 11 and the finishing bucket 1 are sealed grab buckets, but the present invention can be applied to the case where either one or both are open grab buckets with the upper surface of the shell opened. Can be applied.

DESCRIPTION OF SYMBOLS 1 Finishing digging grab bucket 2 Shell 3 Upper frame 4 Lower frame 5 Arm 6a-6c Support shaft 7 Bucket cover 8 Fixed angle 9a Through-hole 9a
9b Open / close door 10a Hanging wire 10b Open / close wire 11 First grab bucket 12 Shell 13 Winch device 14 Work ship

Claims (3)

  The first grab bucket lifted and lowered by the winch device with the first grab bucket performs the dredging while leaving the finishing depth of the finishing digging with respect to the preset dredging depth, and then switches to the first grab bucket A finishing method in which a finishing digging grab bucket having a maximum digging depth smaller than that of the grab bucket and having a maximum opening area is attached to the suspension wire, and finishing digging is performed by the finishing digging grab bucket.   The dredge method according to claim 1, wherein a bucket capacity of the finish digging grab bucket is the same as a bucket capacity of the first grab bucket.   The dredging method according to claim 1 or 2, wherein the finishing digging grab bucket is detachably provided with a bucket cover capable of changing the bucket capacity, and the finishing digging is performed by attaching the bucket cover according to the finishing depth. .

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