JP2016186167A - Modifier mixing method into soft soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a modifier mixing method into soft soil that offers a high degree of freedom of application, and can simply and inexpensively mix soft soil such as dredge soil and a modifier such as steel slag.SOLUTION: A throw-down conveyor 5 is installed such that an edge part on a throw-down side is higher by a desired drop height from a throw-down ground surface in front of a top of slope 2a, and a pair of downstream-side regulating side walls 8, 9 is installed on the throw-down ground surface, the side walls extending in a downstream direction from a throw-down point. Modifier-added soft soil is thrown down between the downstream-side regulating side walls 8, 9 from the throw-down conveyor, the modifier-added soft soil having modifier 4, 4, ... mixed at a prescribed ratio into soft soil 3. Modifier-added soft soil 17 is made to accumulate between the downstream-side regulating side walls 8, 9 while retaining a constant mixture effective thickness. Furthermore, the modifier-added soft soil 17 is thrown down sequentially from the throw-down conveyor 5 onto the modifier-added soft soil 17 accumulated between the downstream-side regulating side walls 8, 9, thus mixing the modifier 4, 4 with the soft soil 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for mixing modifiers with soft soil for improving the strength of soft soil by mixing modifiers such as steelmaking slag and cement produced as a by-product in the refining process of steel with soft soil such as dredged soil. .

  Modified soil made from soft soil such as dredged soil mixed with modified materials such as steelmaking slag and cement produced as a by-product during the steel refining process. Have been proposed (see, for example, Patent Document 1, paragraph 0035).

  As a method of mixing two substances simply and in large quantities, a method of mixing using a belt conveyor connection is known, but this method is mainly used in a dry state or sandy soil having a low water content. It is not suitable for mixing soft soil and steelmaking slag with high water content such as dredged soil with a high silt / clay content (for example, Non-Patent Document 1). See).

  As another method of mixing soft soil and additive, the soft soil with additive added is dropped into a tall tower-shaped cylindrical kneading device, and the inside of the device is dropped. It is also conceivable to mix soft soil and additives using, for example, Patent Document 2).

  However, in the method of mixing soft soil and additives using falling energy, a tall and unstable tower-type kneading device is used, and therefore it is necessary to install the kneading device in a stable state. In addition, there is a problem that the equipment becomes large and the installation place is limited, and such a kneading apparatus is often provided with a stirring means such as a paddle that operates with electric power in order to obtain a sufficient mixing state. There has been a demand for the development of an apparatus capable of mixing soft soil and steelmaking slag with a simpler structure.

  Therefore, as a new modifier mixing method, the advantages of the mixing method using the belt conveyor connection and the method of mixing the soft soil and the additive using the falling energy are utilized, and soft soil such as dredged soil is used. And a reforming material such as steel slag have been developed in a simple and inexpensive manner (see Patent Document 3).

  In this mixing method, steelmaking slag is added to soft soil adjusted to have an appropriate viscosity and fluidity at a predetermined ratio, and the soft soil to which the steelmaking slag is added is connected to each belt conveyor on the downstream side. The soft soil added with steelmaking slag at each transfer between the belt conveyors is dropped from a certain height from the discharge side end of the belt conveyor to collide with the mixing repellent. Steelmaking slag and soft soil are mixed.

JP 2009-121167 A Japanese Patent Application Laid-Open No. 11-028719 JP 2014-173285 A Pre-mixing treatment method technical manual (revised version) Coastal Technology Research Center, December 2008, p. 61

  However, in the conventional technology as described above, after introducing a modifying material such as steel slag into soft soil, a plurality of (at least three or more times) transfer between belt conveyors, and a rebound for mixing and dropping at that time And it is necessary to ensure a certain distance from the position where the modifier such as steelmaking slag is introduced to the soft soil to the final placement position. For example, there is a limitation, and it is not suitable for directly placing the modified soil in a place close to the reclaimer ship such as the back of the revetment.

  Therefore, in view of such a conventional problem, the present invention has a high degree of freedom in application, and is applicable to soft soil that can easily and inexpensively mix soft soil such as clay and a modifier such as steelmaking slag. It was made for the purpose of providing a modifying material mixing method.

  The feature of the invention described in claim 1 for solving the conventional problem as described above is that the modifier is mixed with soft soil at a predetermined ratio, which is introduced from the front of the shoulder, and the slope is allowed to flow down. In the modified material mixing method for soft soil, the dropping conveyor is installed so that the dropping side end portion is higher than the dropping destination ground before the legal shoulder by a desired drop height, and the dropping destination ground is installed. A pair of flow regulation walls extending from the drop point to the downstream in the flow direction is installed, and a modifier added soft soil with a predetermined ratio to a certain amount of soft soil adjusted to the desired water content ratio Is dropped from the dropping conveyor between the flow regulating side walls, the modifier-added soft soil is stored between the flow regulating side walls while maintaining a certain effective mixing thickness, and is stored between the flow regulating side walls. For the dropping on the soft soil added with the modifier The modified material-added soft soil is sequentially dropped from the NVEA to mix the modified material and the soft soil, and the modified soil formed by mixing the modified material and the soft soil is added to the flow regulating side wall. A method of mixing a modifier with soft soil that extrudes the modified soil along the slope and causes the modified soil to flow along the slope.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the ratio of the length in the flow direction of the flow restriction side wall to the wall height is formed larger than the slope of the slope.

  According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the reformed soil pushed out along the flow regulation side wall and flowed down along the slope reaches a certain amount. Every time it is done, the dropping point of the dropping conveyor and the flow regulating side wall are moved along the shoulder.

  According to a fourth aspect of the present invention, in addition to the structure of any one of the first to third aspects, the desired water content ratio is 1.36 to 1.85 times the liquid limit, and the desired mixing efficiency The thickness is 30 cm to 1.5 m.

  As described above, the method for mixing the modifier with the soft soil according to the present invention is to mix the modifier with the soft soil at a predetermined ratio, and then add the modifier from the front of the method to flow down the slope. In the modifying material mixing method for soft soil, a dropping conveyor is installed so that the dropping side end portion is higher than the dropping destination ground before the legal shoulder by a desired drop height, and the dropping point is set on the dropping destination ground. A pair of flow-regulating side walls extending from the downstream in the flow direction is installed, and the modifier-added soft soil obtained by adding the modifier at a predetermined ratio to a certain amount of soft soil adjusted to a desired water content ratio is dropped. Dropped between the flow regulating side walls from the conveyor, the modifier-added soft soil is stored between the flow regulating side walls while maintaining a certain mixing effective thickness, and stored between the flow regulating side walls. The dropping conveyor is placed on soft soil with a modifier added. The modifier-added soft soil is dropped in order to mix the modifier and the soft soil, and the modified soil formed by mixing the modifier and the soft soil is placed along the flow regulating wall. It is not necessary to transfer a plurality of belt conveyors by extruding the modified soil along the slope, so that soft soil and steel making can be made when it is dropped from the dropping conveyor to the ground with a simple structure. A modifying material such as slag can be mixed, and high quality modified soil can be supplied toward the slope.

  Further, in the present invention, by forming a ratio between the flow direction length of the flow regulation side wall and the wall height larger than the slope of the slope, a constant mixing effective between the flow regulation side walls is promoted while promoting flow. It is possible to temporarily store the modifier-added soft soil with a thickness.

  Further, in the present invention, the dropping point of the dropping conveyor and the flow regulating side wall each time the modified soil pushed out along the flow regulating side wall and flowed down along the slope reaches a certain amount. Can be accommodated even when the construction application range is wide.

  Furthermore, in the present invention, the desired water content ratio is 1.36 to 1.85 times the liquid limit, and the desired effective mixing thickness is 30 cm to 1.5 m. Can be implemented.

It is a schematic side view which shows an example of the embodiment of the modifier mixing method with respect to the soft soil which concerns on this invention. It is a partial expanded sectional view which shows the outline of the mixing part in FIG. (A)-(d) is sectional drawing for demonstrating the mixing principle same as the above. It is sectional drawing for demonstrating the movement process of the flow-down control side wall in this invention.

  Next, an embodiment of the method for mixing a modifier with soft soil according to the present invention will be described based on the examples shown in FIGS. In addition, the code | symbol A in a figure is a reclaimed land which casts reformed soil.

  The reclaimed land A is separated from the offshore side by the revetment structure 1, and the slope 2 (slope) gently inclined toward the inside of the reclaimed land A by the modified soil placed on the back side of the revetment structure 1 ) Is formed, and a reforming material such as steelmaking slag or the like is added and mixed at a predetermined ratio to the soft shoulder 3 from the shoulder 2a, that is, before the upper edge of the slope 2 The soil is introduced and the modified soil is driven by flowing down along the slope 2.

  In the method of the present invention, at the time of placing the modified soil, a modified material 4, 4..., Such as steelmaking slag, is added to the soft soil 3 such as dredged soil at a predetermined ratio, and the mixed material is reformed. It is to generate soil.

  The apparatus used in the method of the present invention adjusts the water content ratio of the transfer means 6 including the dropping conveyor 5 for supplying the soft soil 3 such as dredged soil to the landfill A and the soft soil 3 input to the transfer means 6. A water content ratio adjusting means (not shown), a modifier supply means 7 for adding modifiers 4, 4..., Such as steelmaking slag, to the soft soil 3 that moves the transfer means 6; A soft soil 3 (hereinafter referred to as a modifier-added soft soil 17) having a pair of flow-restricting side walls 8, 9 to which the modifiers 4, 4. Has been dropped.

  In addition, this apparatus is provided with a flow promotion means 10 for promoting flow from the flow regulation side walls 8 and 9 to the slope 2 side, and for example, a mud excavator is used as the flow promotion means 10.

  As the transfer means 6, for example, as shown in FIG. 1, an unloading ship (reclaimer ship) floated on the water is used, and soft soil 3 such as dredged soil is unloaded from the ship carrier 12 by the backhoe 11 or the like. Then, it is cut out in a certain amount and sequentially supplied to the front belt conveyor 13, and a modifier 4, 4..., Such as steelmaking slag, is added on the front belt conveyor 13 and then dropped into the conveyor 5. To supply.

  The dropping conveyor 5 is installed on the hull so as to be able to rotate horizontally and vertically, and the dropping side end is higher than the dropping destination ground before the shoulder 2a by a desired drop height h and flows down from the shoulder 2a. It is designed to be located on the front side of the direction.

  Reference numeral 14 in the figure denotes a soft soil supply hopper provided with a feeder capable of adjusting the discharge amount, and the soft soil 3 such as dredged soil pumped by the backhoe 11 etc. is supplied to the soft soil. The hopper 14 is inserted into the hopper 14, cut out at regular intervals, and sequentially supplied to the front belt conveyor 13.

  The water content ratio adjusting means is arranged on the upstream side of the near-side belt conveyor 13 such as a hydrating device for adding water to the soft soil 3 mounted on the earth vessel 12, and the soft soil 3 is used as a modifier 4 such as steelmaking slag. , 4 ... is adjusted to the most suitable water content.

  The soft soil 3 has a water content ratio of 1.36 to 1.85 times the liquid limit (wL), that is, 1.36 wL to 1.85 wL (%), and the soft soil 3 has appropriate viscosity and fluidity. It will be adjusted to the state.

  The reforming material supply means 7 includes, for example, a reforming material supply hopper 15 provided with a feeder whose discharge amount can be adjusted, and a reforming material supply belt conveyor 16 disposed on the front belt conveyor 13. The reforming material 4, 4..., Such as steelmaking slag, cut out by the feeder every predetermined amount, is sequentially fed into the soft soil 3 on the front belt conveyor 13 by the reformer supply belt conveyor 16, and the soft soil 3 The modifiers 4, 4... Such as steelmaking slag are added at a predetermined ratio (10 to 40 vol%).

  As shown in FIGS. 2 and 3, the flow restriction side walls 8 and 9 are extended from the drop point to the downstream side in the flow direction in the flat part of the drop destination ground before the shoulder 2a, and are desired in a direction crossing the flow direction. It is installed so as to face each other with an interval W. In addition, the space | interval W of the flow-down control side walls 8 and 9 can maintain the fixed mixing effective thickness D (30 cm-1.5 m) for the soft soil adjusted to the water content ratio 1.36 wL-1.85 wL (%). It is set.

  Here, the effective mixing thickness D is a thickness that is affected by an impact at the time of dropping, and is a thickness that is sufficient to prevent the diffusion of the modifiers 4, 4. The mixing effective thickness D can obtain a predetermined mixing effect as long as it can maintain a certain thickness (30 cm) or more. However, if the mixing effective thickness D is thicker than necessary (1.5 m), the drop height h decreases accordingly. The upper speed of the effective mixing thickness D is preferably about 1.5 m because the speed at the time decreases and the mixing range becomes smaller.

  The flow restricting side walls 8 and 9 are formed by, for example, building a steel plate or the like, and the installation position can be easily changed.

  The ratio between the flow direction length L of the flow regulation side walls 8 and 9 and the wall height H is formed larger than the slope of the slope 2, and the modifier-added soft soil 17 dropped from the drop conveyor 5 flows down. Storage is possible while maintaining a constant effective mixing thickness D (30 cm to 1.5 m) at the front side in the flow direction between the regulating side walls 8 and 9.

  Further, a closed body 18 that closes the opening on the sea side between the flow-down regulating side walls 8, 9 is disposed at the sea side end portions of the flow-down regulating side walls 8, 9, and the dropped modifier-added soft soil 17 is dropped. Can flow down only to the slope 2 side, and in this embodiment, as shown in FIGS. 1 and 2, the sea side end portions of the flow restriction side walls 8 and 9 are covered with the back portion of the revetment structure 1. It is made to contact | abut to the end surface of 1a, and the end surface of the back part 1a is made into the obstruction | occlusion body 18. FIG. The closing body 18 may be made of a plate material such as a steel plate, and the closing body 18 and both the flow-down regulating side walls 8 and 9 may form a U-shaped frame body having a downstream opening in the flow direction. .

  Furthermore, both the flow-down regulating side walls 8 and 9 are installed on the back-filling portion 1a made of a back-filled stone or solidified modified soil before the shoulder 2a, for example, so It is preferable to secure strength at the bottom, and when the strength of the bottom between the two flow-down regulating side walls 8, 9 is insufficient due to installation on the reformed soil layer before solidification, the double flow-down regulating side wall 8, A steel plate is arranged at the bottom between 9 and strength is ensured at the bottom between both flow regulation side walls 8 and 9.

  Next, the specific procedure of the modifier mixing method for soft soil will be described.

  First, as shown in FIG. 1, the transfer means (reclaimer ship) 6 is moved to a predetermined position in the vicinity of the revetment, and the drop-side end of the drop conveyor 5 is moved to a position before the shoulder 2a to a desired drop height from the ground. Install the unit so that it is higher by h.

  Further, in accordance with the setting of the dropping conveyor 5, the flat portion of the destination ground before the shoulder 2 a extends from the dropping point to the downstream side in the flow direction and faces each other at a desired interval W in the direction intersecting the flow direction. A pair of flow-down regulating side walls 8 and 9 are installed as described above.

  Next, after measuring the water content ratio of the soft soil 3 such as dredged soil carried by the soil carrier 12 in advance, the water content is adjusted by means of water content ratio adjusting means. It adjusts so that it may be in the state suitable for mixing of the material 4,4 ..., ie, the state which has moderate viscosity and fluidity (the soft soil 3 has a water content ratio of 1.36 wL to 1.85 wL (%)). .

  Next, the soft soil 3 whose water content ratio is adjusted is pumped up by the backhoe 11 or the like, and is put into the soft soil supply hopper 14.

  The soft soil 3 introduced into the soft soil supply hopper 14 is cut out by a predetermined amount, introduced into the front belt conveyor 13, and transported in a leveled state on the front belt conveyor 13.

  Then, the modifiers 4, 4..., Such as steelmaking slag, are added to the fixed amount of the soft soil 3 transferred from the modifier supply means 7 at a predetermined ratio. That is, the reforming materials 4, 4... Are cut out from the reforming material supply hopper 15 at regular intervals, and are sequentially transferred onto the front belt conveyor 13 by the reforming material supply belt conveyor 16, and soft soil. 3 is added at a predetermined ratio. At that time, since the soft soil 3 has a moisture content of a certain level or more, the modifiers 4, 4... Having a higher specific gravity than the soft soil 3 are in a state of being embedded in the soft soil 3.

  Then, the soft soil 3 to which the modifiers 4, 4... Such as steelmaking slag are added (hereinafter referred to as the modifier-added soft soil 17) is transferred onto the dropping conveyor 5, and FIG. As shown, it is dropped sequentially from the end of the drop conveyor 5 between the flow-down regulating side walls 8 and 9 on the destination ground.

  Since the dropped modifier-added soft soil 17 is regulated to flow laterally by the flow regulation walls 8, 9, at the dropping point, that is, at the front side in the flow direction between the flow regulation walls 8, 9. Overlaid one after another, and temporarily stored while maintaining a constant mixed effective thickness D (30 cm to 1.5 m). When the mixed effective thickness D is exceeded, the weight of the newly added modifier-added soft soil 17 is increased. The part of the modified soil that has already been mixed is pushed out toward the shoulder 2a.

  In that case, first, as shown in FIG. 3A to FIG. 3B, the dropped modifier-added soft soil 17a is placed on the modifier-added soft soil layer 20 that is primarily stored at the drop point. The soft soil 3 is mixed with the upper layer of the existing soft soil 3 by the impact at that time, and the modifiers 4, 4... Having a higher specific gravity than the soft soil 3 are mixed in the existing soft soil 3. To spread.

  Next, as shown in FIGS. 3 (c) to 3 (d), when a new modifier-added soft soil 17 b is dropped, the existing modifier-added soft soil 17 a dropped before that The soft soils 3 are mixed with each other by falling to the overlapping portion, and the modifiers 4, 4... Of the new modifier-added soft soil 17b are added to the existing modifier-added soft soil 17a. While being diffused, the modifiers 4, 4... Of the existing modifier-added soft soil layer 17a further diffuse toward the outside.

  Therefore, by repeating the series of operations shown in FIGS. 3A to 3D, the new modifier added soft soil 17b to be sequentially dropped is added to the existing modifier added before that. The impact on the soft soil 17a is repeated, and the impact causes the modifiers 4, 4 ... to diffuse evenly in the soft soil 3, and the soft soil 3 and the modifiers 4, 4 ... are mixed. Modified soil is produced.

  On the other hand, when the modified material-added soft soil layer 20 exceeds a certain mixing effective thickness D, the reformed material-added soft soil 17 is reformed by the weight of the newly-added modified material-added soft soil 17 and the pressure from the side walls 8 and 9 that restrict the flow down. The materials 4, 4... Are repeatedly diffused from the existing portion of the modified soil in a sufficiently mixed state toward the shoulder 2 a side.

  In this series of mixing steps, for example, when the effective mixing thickness D is set to 30 cm and the average volume of each modified material-added soft soil 17a is 5 liters, the area affected by the drop is 50 × 50 cm. Assuming that the constant mixing effective thickness D = 30 cm is maintained, the volume of the portion to be mixed is maintained at 15 times (75 liters) of the volume (5 liters) of each modifier-added soft soil 17a. Each time a new modifier-added soft soil 17a is introduced, the existing modifier-added soft soil 17 is pushed out in the flow direction, so that 5 liters of the newly added modifier-added soft soil 17 flows down. It is calculated that the dropping of the new modifier-added soft soil 17 is repeated 15 times before being pushed out in the direction, and kneading is performed every time, so the modifier-added soft soil 17 is dropped and pushed out. 15 times So that the kneading is repeated.

  Next, the flow of the reformed soil generated from the flow regulating side walls 8 and 9 toward the slope 2 side is promoted by using the flow facilitating means 10 such as a mud excavator, etc. It is made to flow along the slope 2 by the shoulder flow method and is placed in the landfill A.

  Further, when the placement range is wide, etc., as shown in FIG. 4, the dropping conveyor 5 every time when the modified soil flowed down along the slope 2 reaches a certain amount as necessary. The above-described series of operations may be repeated by moving the drop-off point and the flow-down regulating side walls 8 and 9 along the shoulder 2a.

  In the modification material mixing method for soft soil thus configured, the soft soil 3 is adjusted to a water content ratio (1.36 wL to 1.85 wL (%)) suitable for mixing, and the soft soil 3 has an appropriate viscosity and Since it has fluidity, it is stored while maintaining a constant mixing effective thickness D (30 cm to 1.5 m) between the flow regulating side walls 8 and 9, and is newly added to the existing modifier-added soft soil layer 20. When the appropriate modifier-added soft soil 17 is dropped, as shown in FIG. 3, the soft soil 3 is taken into the upper layer of the modifier-added soft soil layer 20 so that water is disturbed by the waterfall. The modifiers 4, 4... Are diffused and mixed by impact when colliding with the existing modifier-added soft soil layer 20, and the mixing is repeated every time the modifier-added soft soil 17 is dropped.

  Therefore, a predetermined kneading effect can be obtained at the point where it is dropped from the dropping conveyor 5, it is not necessary to transfer a plurality of conveyors, and it is suitably high even in a place near the reclaimer ship such as the back side of the revetment structure 1. Quality modified soil can be supplied.

  Next, a reference experiment for verifying the effect of the modifying material mixing method on the soft soil according to the present invention will be described. In addition, the same code | symbol is attached | subjected and demonstrated to the structure similar to the above-mentioned Example.

  In this experiment, the water content ratio was adjusted by adding water to soft soil 3 (liquid limit wL = 101.3%) such as dredged soil, and steelmaking slag, etc. at a predetermined ratio (30 vol% in this experiment). Drop the modified material-added soft soil 17 (samples 1 to 7) to which the modified materials 4, 4... Are added from the drop height h (h = 5 m) between the flow regulation walls 8 and 9. The uniaxial compressive strength of the modified soil produced on the 28th day is measured by mixing work, and the average compressive strength and visual modifier of soft soil 3 and steelmaking slag, etc. 4, 4. The mixed state with .. was evaluated.

  The modified soil produced in the same manner also when the thickness D of the modifier-added soft soil layer 20 temporarily stored between the flow regulating side walls 8 and 9 is different (D = 10 cm, 30 cm, 50 cm). The uniaxial compressive strength on the 28th day of material age was measured, and the mixed state was evaluated by the average strength and visual observation.

  In this experiment, the uniaxial compressive strength (hereinafter referred to as “indoor blending strength”) of the specimen uniformly mixed with the same blending as in each case above was measured in advance, and the average strength of each sample was measured indoors. Evaluation was made based on whether or not the strength ratio β to the blending strength (= average strength for each sample / indoor blending strength) satisfied 0.7 or more.

  That is, the uniaxial compressive strength of the generated modified soil depends on the degree of kneading between the soft soil and the modifying material. The degree of kneading between the soft soil and the modifier of each sample is evaluated by the uniaxial compressive strength of the sample, that is, the strength ratio β.

The standard strength ratio β is standardized based on past construction data in this type of pre-mixing method. If the purpose of using the modified soil is only to prevent liquefaction, the strength ratio β The ratio β is set to 0.5 and the strength ratio β is set to 0.7 when the purpose is to reduce earth pressure. For the evaluation of the present invention, a method satisfying the strength ratio β = 0.7 or more was set with the aim of a method with better kneadability.
The results are shown in Table 1.

  When the moisture content of the soft soil 3 is low (water content ratio 1.23 wL (%)), the strength ratio is less than 0.7 in any effective mixing thickness D, and sufficient strength is not exhibited. It was confirmed that it was not.

  Further, even when the water content ratio is high (water content ratio 1.97 wL (%)), in any effective mixing thickness D, the strength ratio is less than 0.7, and sufficient strength is not exhibited, and the mixture is sufficiently mixed. Not confirmed.

  Furthermore, even when the moisture content of the soft soil 3 is 1.36 wL to 1.85 wL (%), when the effective mixed thickness D of the modifier-added soft soil layer 20 is 10 cm, the strength ratio is It was less than 0.7 and remained below half of the indoor blending strength.

  On the other hand, when the moisture content of the soft soil 3 is 1.36 wL to 1.85 wL (%) and the effective mixed thickness D of the modifier-added soft soil 17 is 30 cm or more (D = 30 cm and 50 cm), In this case, the strength ratio β is 0.7 or more, and even by visual confirmation, it was confirmed that the modifiers 4, 4 ... such as steelmaking slag were uniformly mixed in the soft soil 3. .

  Therefore, in the mixing of the soft soil 3 and the modifiers 4, 4... According to the present invention, the soft soil 3 is adjusted to have a desired water content, and the soft soil 3 has an appropriate viscosity and fluidity. It was confirmed that a suitable mixed state could be obtained by adjusting the water content ratio of the soft soil 3 to 1.36 wL to 1.85 wL (%).

  In addition, in the mixing of the soft soil 3 of the present invention and the modifiers 4, 4... Such as steelmaking slag, it is sufficient to ensure a mixing effective thickness D (30 cm or more) above a certain level at the dropping point. It was also confirmed that the strength was secured.

  In the above-described embodiment, the example in which the steelmaking slag is added to the soft soil 3 flowing on the front belt conveyor 13 using the modifying material supply belt conveyor 16 is described. The means for adding the slag is not limited to the above-described embodiment. For example, the soft soil 3 cut into a certain amount directly is put into the dropping conveyor 5 and a certain amount is placed on the soft soil 3 flowing on the dropping conveyor 5. You may make it throw in modifiers 4,4 ..., such as steelmaking slag cut out every time.

  In the above-described embodiment, the example in which the steelmaking slag is applied to the reforming materials 4, 4 ... has been described. However, the reforming materials 4, 4 ... are not limited to the steelmaking slag, for example, cement. There may be.

A Reclamation site 1 Revetment structure 2 Slope 3 Soft soil 4 Reformer 5 Dropping conveyor 6 Transfer means 7 Reformer supply means 8, 9 Drainage regulation side wall
DESCRIPTION OF SYMBOLS 10 Flow down promotion means 11 Backhoe 12 Earth transport ship 13 Front side belt conveyor 14 Soft soil supply hopper 15 Reformer supply hopper 16 Reformer supply belt conveyor 17 Reformant addition soft soil 18 Closure body 20 Reformant Additive soft soil layer

Claims (4)

In the modifying material mixing method for the soft soil, the modifying material is mixed with the soft soil at a predetermined ratio, it is thrown from the front of the shoulder, and the slope is allowed to flow down.
A pair of dropping conveyors are installed so that the dropping side end portion is higher than the dropping destination ground before the above-mentioned shoulder by a desired drop height, and the pair is extended on the dropping destination ground from the dropping point to the downstream side in the flow direction. The side wall of the flow regulation of
A modifier-added soft soil obtained by adding a modifier to a predetermined amount of soft soil adjusted to a desired water content ratio is dropped between the flow regulating side walls from the dropping conveyor, and between the flow regulating side walls. The modified material-added soft soil is stored while maintaining a certain effective mixing thickness, and the modified material-added soft soil is transferred from the dropping conveyor onto the modified material-added soft soil stored between the flow regulation walls. By sequentially dropping the soil, the modifier and the soft soil are mixed, and the modified soil formed by mixing the modifier and the soft soil is extruded in the flow direction along the flow regulating side wall. A modifying material mixing method for soft soil, wherein the modified soil is allowed to flow along the slope.   The method for mixing a modifier with soft soil according to claim 1, wherein a ratio between the length in the flow direction of the flow regulation side wall and the wall height is formed larger than the slope of the slope.   Each time the modified soil pushed down along the slope and flowed down along the slope reaches a certain amount, the drop point of the drop conveyor and the flow restriction side wall follow the shoulder. The modifier mixing method for soft soil according to claim 1 or 2, wherein the modifier is moved.   The desired water content ratio is 1.36 to 1.85 times the liquid limit, and the desired mixing effective thickness is 30 cm to 1.5 m. Modification to soft soil according to any one of claims 1 to 3 Material mixing method.

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