Underwater anti-dispersion cement soil, preparation device and preparation method

Abstract

The invention discloses underwater anti-dispersion cement soil, a preparation device and a preparation method. The underwater anti-dispersion cement soil comprises waste soft clay, a curing agent, water, an anti-dispersion agent and a fiber material, the waste soft clay is selected from marine-facies muddy clay or river-facies muddy clay; the curing agent is selected from ordinary Portland cement; the mass ratios of the curing agent, the anti-dispersing agent and the fiber material to the waste soft clay are respectively 5-20%, 0.25 per mill to 0.75 per mill and 0.2-0.6%. The device comprises a stirring barrel, stirring blades, a backflow barrel and a suction device, the top of each stirring blade is provided with a fiber dispersion plane, and each stirring blade is uniformly provided with a plurality of fiber distribution holes; the suction device is arranged on the outer side of the mud separation bin and can suck cement soil at the bottom of the stirring barrel to the top of the backflow barrel. According to the invention, fibers can be uniformly mixed with cement soil, and the phenomena of non-uniform local stirring of the cement soil and cracking generated after hardening of the cement soil can be prevented.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering materials and preparation and construction, in particular to underwater anti-dispersion cement soil, a preparation device and a preparation method. Background Art

[0002] As society's demand for energy continues to increase, in order not to occupy too much land resources, offshore wind power equipment is increasing, and corresponding engineering problems are gradually emerging. Pile foundations are one of the most important foundation forms for bridges and offshore wind power structures. Under the long-term action of water flow, scour pits are prone to appear around them, resulting in a decrease in bearing capacity. Traditional pile foundation anti-scour measures in engineering include building riprap protection and sand blanket protection, but the engineering cost of obtaining sand and gravel resources is relatively high. At the same time, a large amount of waste soil generated in the municipal and waterway fields needs to be handled. How to use the waste soil for pile foundation scour repair is a practical issue.

[0003] Cement soil is a composite of waste soft clay, cement, water and other materials. Although it has low compressibility and is environmentally friendly, its strength is limited. In order to improve performance, fiber reinforcement technology is often used to add fibers and anti-dispersants. Although the strength and anti-dispersibility are significantly enhanced, the strength is often affected by fiber entanglement and some fluidity is sacrificed. The ratio needs to be optimized to take into account the fluidity, anti-dispersibility and strength required for underwater construction. In addition, traditional mixing devices are difficult to ensure that the cement soil is fully uniform, especially in corners, which increases the difficulty of construction. At the same time, the large amount of heat released during the cement hydration process causes the internal temperature to rise, and the subsequent self-contraction during the cooling process can easily cause cracks, which damages durability and strength. Comprehensive technical improvements are urgently needed to improve overall performance and application effects.

[0004] Therefore, it is necessary to develop an underwater anti-dispersion cement-soil mix with high anti-dispersion performance, good flowability and good mechanical properties, and to develop a cement-soil preparation device and method with uniform mixing and rapid condensation functions to address the problems of cracks caused by uneven fiber mixing and hydration heat. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an underwater anti-dispersion cement soil, a preparation device and a preparation method for the above-mentioned deficiencies of the prior art. The underwater anti-dispersion cement soil, the preparation device and the preparation method add an appropriate amount of anti-dispersion agent and fiber material to the cement soil, so that the cement soil has good anti-dispersion, fluidity and compressive strength, and can be effectively applied to pile foundation scour control. In order to evenly mix the fiber with the cement soil during the production process, and to prevent uneven local mixing of the cement soil and more cracking after the cement soil hardens, an underwater anti-dispersion cement soil preparation device is proposed.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] An underwater anti-dispersion cement soil comprises waste soft clay, a curing agent, water, an anti-dispersion agent and a fiber material; wherein the curing agent is selected from ordinary Portland cement.

[0008] The mass ratios of the curing agent, the anti-dispersion agent and the fiber material to the waste soft clay are 5% to 20%, 0.25‰ to 0.75‰ and 0.2% to 0.6% respectively.

[0009] The water is 1.4 to 2 times the liquid limit of abandoned soft clay.

[0010] The waste soft clay is selected from marine silt clay or river silt clay.

[0011] The fiber material is polyester fiber, basalt fiber, glass fiber, polypropylene fiber, sisal fiber or polyvinyl alcohol fiber.

[0012] Anti-dispersant is a high molecular polymer.

[0013] The anti-dispersing agent is polyacrylamide, xanthan gum, ethylene-vinyl acetate copolymer or hydroxypropyl methylcellulose.

[0014] An inclined mud separator is integrally arranged at the bottom of the mixing barrel.

[0015] The reflux barrel is coaxially arranged at the center of the stirring barrel and can rotate actively; a reflux gap is provided between the bottom of the reflux barrel and the bottom of the stirring barrel, and a reflux port is provided at the bottom of the reflux barrel.

[0016] There are a plurality of stirring blades which are evenly arranged along the circumference of the middle part of the reflux barrel and are all detachably connected to the reflux barrel.

[0017] The top of each stirring blade is provided with a fiber dispersing plane, and each stirring blade is evenly provided with a plurality of fiber distributing holes.

[0018] The suction device is arranged outside the mud separator and can suck the cement soil at the bottom of the mixing barrel to the top of the reflux barrel.

[0019] A condensing device is also included.

[0020] The condensing device is arranged on the mud outlet pipe at the bottom of the mixing barrel, and comprises a condenser, an inner condensing pipe, an outer condensing pipe and a heat insulation bin.

[0021] The inner condenser pipe, the mud outlet pipe and the outer condenser pipe are coaxially arranged in sequence; and the inner condenser pipe is connected to the outer condenser pipe.

[0022] The condensers are connected to the free ends of the inner condenser tube and the outer condenser tube respectively.

[0023] The heat-insulating chamber is wrapped around the outer condenser pipe and the outer periphery of the condenser.

[0024] It also includes a pressure pump; the pressure pump is arranged on the mud outlet pipe downstream of the condensation device.

[0025] Each stirring blade is a rectangular blade arranged obliquely; and racks are arranged on the periphery of each stirring blade.

[0026] A method for preparing underwater anti-dispersion cement soil comprises the following steps.

[0027] Step 1, spreading fiber material: first, all stirring blades are removed from the periphery of the reflux barrel; then, a set amount of fiber material is evenly spread on the fiber dispersion planes of all stirring blades; finally, the stirring blades spread with fiber material are sequentially installed on the periphery of the reflux barrel;

[0028] Step 2: Add the set amount of waste soft clay, curing agent, water and anti-dispersant into the mixing barrel outside the return barrel in sequence.

[0029] Step 3, stirring: The return barrel rotates actively, driving the stirring blade to rotate synchronously, and the fiber material spread on the stirring blade is evenly dispersed in the return barrel through the fiber distribution hole, and the waste soft clay, curing agent, water, anti-dispersant and fiber material are evenly mixed.

[0030] Step 4, reflux: During the stirring process, a suction device is used to return the stirring mud at the bottom of the stirring barrel to the bottom of the reflux barrel; the stirring mud entering the reflux barrel flows back from the reflux port at the bottom of the reflux barrel to the middle of the stirring barrel, and continues to be stirred evenly.

[0031] Step 5, condensation: the mud material after reflux stirring is discharged from the mud outlet pipe and condensed by the condensation device.

[0032] Step 6: Pressurize: discharge the condensed mud under pressure.

[0033] The present invention has the following beneficial effects:

[0034] Compared with the prior art, the present invention has the following characteristics and advantages:

[0035] (1) In current projects, the scour protection for pile structures such as offshore wind power foundations is still mainly based on stone throwing measures. This method has poor integrity, and sand and gravel materials are often obtained through blasting and other methods, resulting in high project costs. At the same time, with the increase in various waterway regulation projects, a large amount of waste silt soil is difficult to use directly, and the process of stacking waste soil causes environmental problems such as dust and flying sand. The present invention adds cement, anti-dispersant and other admixtures to the waste soil to produce underwater anti-dispersible cement-cured soil for pile structure scour repair. This not only solves the source of anti-scour and filling materials and reduces project costs, but also consumes waste soil to a large extent, turning waste into treasure, and is green and environmentally friendly.

[0036] (2) The underwater anti-dispersion cement soil proposed in the present invention uses marine muddy clay and river muddy clay, with a cement content of 5% to 20%, a water content of 1.4 to 2 times the liquid limit, an anti-dispersion agent polyacrylamide content of 0.25‰ to 0.75‰, and a polyester fiber content of 0.2 to 0.6%. This ratio has been tested for fluidity, anti-dispersion, and unconfined compression, and has excellent fluidity and anti-dispersion, and high strength. It solves the problem that underwater anti-dispersion cement soil has insufficient fluidity due to excessive fiber and anti-dispersion agent content, and low strength and anti-dispersion performance due to insufficient content. It is a cement soil ratio recommended for marine or river muddy clay base materials for pile foundation scour repair.

[0037] (3) In the existing cement soil mixing process, by directly placing the fibers into the cement soil and stirring, the fibers are often mixed unevenly in the cement soil matrix. The fibers are entangled and knotted with each other, reducing the fluidity and strength of the cement soil. Compared with the traditional process, the cement soil preparation device proposed in the present invention arranges a number of distribution holes on a detachable hollow stirring blade, and the fibers are evenly placed inside the stirring blade before the cement, soil sample, etc. are placed in the mixing barrel. The rotating reflux barrel drives the stirring blade to rotate, and the cement soil takes away the fibers therein through the distribution port. The fibers can be more evenly distributed in the cement soil, avoiding the phenomenon of uneven fiber mixing and entanglement.

[0038] (4) Traditional stirring devices are mostly a single combination of a stirring barrel and stirring blades. The cement soil at the bottom of the stirring barrel will be stirred much less than the cement soil in the upper part of the stirring barrel, which will lead to uneven distribution of the various components of the cement soil. Compared with the traditional stirring device, the present invention has a mud separator arranged obliquely in the stirring barrel, and a mud pump is placed inside the mud separator. The mud pump is used to extract the cement soil and introduce it into the rotating reflux barrel. The cement soil then returns to the stirring barrel through the reflux port in the reflux barrel. The cement soil refluxes through the combined reflux effect of the mud pump and the reflux barrel in the stirring barrel, which avoids the phenomenon of uneven local stirring of the cement soil at the bottom of the stirring barrel and improves the stirring efficiency.

[0039] (5) In the existing technology, cement hydration generates a large amount of heat, which will cause a large temperature difference between the inside of the cement soil and the external water flow. As the temperature inside the cement soil drops, more shrinkage cracks will be generated after hardening. The cement soil preparation device proposed in the present invention arranges inner and outer double-ring condensers on the mud outlet pipe. The condenser pipes filled with condensed water condense the output cement soil; at the same time, the insulation effect of the insulation bin and the pressurization effect of the pressure pump behind it on the cement soil, the two combined to reduce the negative impact of the external temperature and the long-term transportation of cement soil in the conduit on the condensation effect, and reduce the phenomenon of cracking of cement soil after hardening. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1The schematic diagram of the structure of the underwater anti-dispersion cement soil preparation device of the present invention is shown.

[0041] Figure 2 A partial cross-sectional view of the stirring device is shown.

[0042] Figure 3 Shows the front view of the reflux barrel and stirring blades.

[0043] Figure 4 A longitudinal cross-section of the condensation section is shown.

[0044] Figure 5 Shows Figure 4 Middle AA section view.

[0045] Figure 6 Shows a longitudinal section of the outer ring connecting shaft (without the inner connecting shaft installed).

[0046] Figure 7 A longitudinal section of a stirring blade is shown.

[0047] Figure 8 The underwater conduit method construction drawing is shown.

[0048] Fig. 9 The graph shows the change of the expansion degree of fresh cement soil and the strength after 28 days of curing with cement content when the polyester fiber content is 0.6%, twice the liquid limit, and the polyacrylamide content is 0.5‰.

[0049] Fig.10 The graph shows the change of the expansion degree of fresh cement soil and the strength after 28 days of curing with the polyacrylamide dosage when the polyester fiber dosage is 0.6%, twice the liquid limit, and the cement dosage is 10%.

[0050] Among them, 1-mixing barrel, 2-mixing barrel wall, 3-mixing blade, 4-fiber distribution hole, 5-tooth rack, 6-outer ring connecting shaft, 7-fixing nut, 8-inner connecting shaft, 9-connecting sleeve hole, 10-stud, 11-mud pump, 12-mud separation bin, 13-mud suction pipe, 14-mud discharge steel pipe, 15-mud pump wire, 16-reflux barrel, 17-reflux port, 18-rotating shaft, 19-rotating motor, 20-mud discharge plate, 21-mud discharge pipe, 22-discharge valve, 23-tension spring, 24-condenser, 25-refrigeration section, 26-refrigeration section wire, 27-insulation bin, 28-condenser, 29-outer condenser, 30-inner condenser, 31-support rod, 32-pressurization section, 33-pressurization pump, 34-pressurization section wire, 35-support leg, 36-cement soil mud, 37-fan foundation. DETAILED DESCRIPTION

[0051] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.

[0052] In the description of the present invention, it should be understood that the terms "left side", "right side", "upper part", "lower part" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. "First", "second" and the like do not indicate the importance of the components, and therefore cannot be understood as limiting the present invention. The specific dimensions used in this embodiment are only for illustrating the technical solution, and do not limit the scope of protection of the present invention.

[0053] An underwater anti-dispersion cement soil comprises waste soft clay, a curing agent, water, an anti-dispersion agent and a fiber material.

[0054] The waste soft clay may be waste silt soil generated during foundation excavation, channel excavation in channel regulation engineering, road excavation in municipal engineering, land transformation, etc. In this embodiment, marine silt clay or river silt clay is preferred.

[0055] The curing agent is ordinary silicate cement, and the cement content is 5% to 20% according to the mass ratio of ordinary silicate cement to soft clay. Preferably, the curing agent is PO42.5 silicate cement, and the content is 10%.

[0056] The fiber material can be one or a combination of polyester fiber, basalt fiber, glass fiber, polypropylene fiber, sisal fiber and polyvinyl alcohol fiber. In this embodiment, polyester fiber is preferably used. According to the ratio of polyester fiber to soft clay mass, the polyester fiber content is 0.2% to 0.6%. Preferably, the polyester fiber content is 0.6%.

[0057] The anti-dispersant is a high molecular polymer, which can be one or a combination of polyacrylamide, xanthan gum, ethylene-vinyl acetate copolymer or hydroxypropyl methylcellulose. In this embodiment, polyacrylamide is preferred. According to the ratio of its mass to the soft clay, the amount of the anti-dispersant is 0.25‰ to 0.75‰. Preferably, the amount of the anti-dispersant is 0.5‰.

[0058] The water content is preferably 1.4 to 2 times the liquid limit. Further, in this embodiment, a water content of 2 times the liquid limit is selected.

[0059] like Figure 1 and Figure 2 As shown, an underwater anti-dispersion cement soil preparation device includes a stirring barrel 1, a stirring blade 3, a reflux barrel 16, a suction device, a condensing device and a pressure pump 33.

[0060] The mixing barrel 1 is preferably a cylindrical container, and a plurality of supporting legs 35 are arranged outside the mixing barrel.

[0061] The bottom of the mixing barrel is integrally provided with an inclined mud separator 12, and the bottom of the mixing barrel located inside the mud separator is also provided with a mud outlet, which is preferably provided with a mud outlet plate 20, and the outer side of the mud outlet is connected to a mud outlet pipe 21. In order to prevent the underwater anti-dispersion cement soil from having many cracks after hardening due to high temperature, the mud outlet pipe is preferably arranged with a cooling section 25 and a pressurizing section 32 in sequence along the flow direction.

[0062] The above-mentioned mud discharge plate can be opened and closed, and the preferred opening and closing method is: a discharge valve 22 is preferably arranged on the mud discharge pipe adjacent to the mud discharge plate, one side of the mud discharge plate 20 of the discharge pipe is hinged to the bottom end of the mixing barrel 1, and the other side is connected to a tension spring 23, and the discharge valve 22 controls the tension spring 23 to realize the switching of the mud discharge plate 20.

[0063] The reflux barrel is coaxially arranged at the center of the stirring barrel and can rotate actively; there is a reflux gap between the bottom of the reflux barrel and the bottom of the stirring barrel, and a reflux port 17 is arranged at the bottom of the reflux barrel.

[0064] The active rotation of the reflux drum is preferably driven by a rotary motor 19 , which is connected to the bottom of the reflux drum via a rotary shaft 18 .

[0065] like Figure 3 , Figure 6 and Figure 7 As shown, there are several stirring blades, preferably three, which are evenly arranged along the circumference of the middle part of the reflux barrel and are all detachably connected to the reflux barrel.

[0066] The above-mentioned detachable connection method between the stirring blade and the reflux barrel is preferably: the side of the reflux barrel 16 is equipped with an outer ring connecting shaft 6 equal to the number of the stirring blades, and the outer ring connecting shaft 6 is a cylindrical columnar structure, one end of which is fixed to the reflux barrel and the other end is open.

[0067] Each stirring blade has a fiber dispersing plane on the top, and a plurality of fiber distribution holes 4 are evenly distributed on each stirring blade. Each stirring blade is preferably a rectangular blade arranged obliquely.

[0068] In order to evenly disperse the fiber material in the cement soil slurry 36 and to increase the service life of the stirring blades 3, racks 5 are evenly arranged on the periphery of each stirring blade, and the racks of two adjacent stirring blades mesh with each other.

[0069] The inner end of each stirring blade is provided with an inner connecting shaft 8, which is preferably a semi-cylindrical structure with a diameter sufficient to be inserted into the outer ring connecting shaft 6. Connecting sleeve holes 9 are opened at corresponding positions of the outer ring connecting shaft 6 and the inner connecting shaft 8. The inner connecting shaft 8 is inserted into the connecting sleeve hole 9, and the threaded connection between the stirring blade and the reflux barrel 16 is achieved by fixing the nut 7 and the stud 10.

[0070] In this embodiment, the fixing nut 7 is loosened, the stud 10 is taken out from the connecting sleeve hole 9, the stirring blade 3 is disassembled, the polyester fiber is evenly scattered inside the stirring blade 3, and then the stirring blade 3 is reinstalled.

[0071] The suction device is arranged outside the mud separator and can suck the cement soil at the bottom of the mixing barrel to the top of the reflux barrel.

[0072] like Figure 2 As shown, in order to achieve uniform mixing of underwater anti-dispersion cement soil, a suction device is installed outside the mud compartment inside the mixing barrel 1. The suction device includes a mud pump 11, a mud pipe 13 and a mud outlet steel pipe 14. The mud pump 11 is isolated from the cement soil by the inclined mud compartment 12, and the mud pump wire 15 is led out through the channel opened in the mixing barrel wall 2. The mud pipe 13 at one end of the mud pump 11 passes through the mud compartment 12 and contacts the cement soil mud in the mixing barrel 1, and the mud outlet steel pipe 14 at the other end is fixed to the mixing barrel wall and connected to the reflux barrel 16.

[0073] like Figure 1 , Figure 4 and Figure 5 As shown, the condensing device is arranged on the refrigeration section of the mud outlet pipe, and preferably includes a condenser 24, a condensing pipe 28 and an insulation bin 27.

[0074] The condensing device is preferably arranged obliquely, and the condensing pipe includes an inner condensing pipe 30 and an outer condensing pipe 29 which are interconnected. The inner condensing pipe, the mud discharge pipe and the outer condensing pipe are coaxially arranged in sequence, and the condenser is connected to the free ends of the inner condensing pipe and the outer condensing pipe respectively; the heat insulation chamber is coated on the outer condensing pipe and the outer periphery of the condensing pipe.

[0075] That is, one end of the condenser tube 28 is preferably connected to the inner ring condenser tube 30, and the other end is connected to the outer ring condenser tube 29. The inner ring condenser tube 30 is arranged in the middle of the mud outlet tube 21 and fixed by a plurality of support rods 31. The outer ring condenser tube 29 is sleeved on the outside of the mud outlet tube 21. The refrigeration section is wrapped by the insulation bin 27.

[0076] The pressurizing section 32 reduces the time that the condensed cement soil stays in the mud outlet pipe 21 by installing a pressurizing pump 33 on the mud outlet pipe 21 .

[0077] A method for preparing underwater anti-dispersion cement soil comprises the following steps.

[0078] Step 1, spreading fiber material: first, all stirring blades are removed from the periphery of the reflux barrel; then, a set amount of fiber material is evenly spread on the fiber dispersion planes of all stirring blades; finally, the stirring blades spread with fiber material are sequentially installed on the periphery of the reflux barrel;

[0079] Step 2: Add the set amount of waste soft clay, curing agent, water and anti-dispersant into the mixing barrel outside the return barrel in sequence.

[0080] In this example, if Figure 1 As shown by the arrows, the weighed soil sample, cement, anti-dispersant and water are transported into the mixing barrel 1. When the mixing barrel 1 is almost full, the rotating motor 19 is started to drive the mixing blade 3 to rotate, and the cement soil passes through the fiber distribution hole 4 and takes away the internal fibers, so that the fiber material can be evenly distributed in the cement soil mud.

[0081] Step 3, stirring: The return barrel rotates actively, driving the stirring blade to rotate synchronously, and the fiber material spread on the stirring blade is evenly dispersed in the return barrel through the fiber distribution hole, and the waste soft clay, curing agent, water, anti-dispersant and fiber material are evenly mixed (stir at a uniform speed until no clumping of fibers can be seen by the naked eye, and then conduct fluidity test and anti-dispersion test).

[0082] Step 4, reflux: During the mixing process, the mixing mud at the bottom of the mixing barrel is refluxed to the bottom of the reflux barrel by a suction device; the mixing mud entering the reflux barrel flows back to the middle of the mixing barrel from the reflux port at the bottom of the reflux barrel, and continues to be mixed evenly. That is, while mixing, the mud pump 11 is started to pump part of the cement soil in the mixing barrel 1 into the reflux barrel 16, and the cement soil in the reflux barrel 16 returns to the mixing barrel 1 through the reflux port 17 at the bottom of the barrel, so that all the cement soil can be completely and evenly mixed and the fibers can be evenly dispersed in the cement soil.

[0083] Step 5, condensation: the mud material after reflux stirring is discharged from the mud outlet pipe and condensed by the condensation device.

[0084] In this example, after the underwater anti-dispersion cement soil is mixed, the discharge valve is rotated to pull the tension spring 23 to open the mud discharge plate 20, and the mixed cement soil is discharged through the mud discharge pipe 21. At the same time, the condenser 24 is started, and the condensed water flows into the inner ring condenser tube 30 from the lower end. After it is full, the condensed water overflows into the outer ring condenser tube 29. After the condensed water is full in the outer ring condenser tube 29, it flows back to the condenser from the higher end of the condenser tube 28 to achieve condensed water reflux. At the same time, the outermost layer of the refrigeration section 25 is arranged with an insulation bin 27 to isolate it from the outside air and enhance the refrigeration effect of the refrigeration section 25. The refrigerated underwater anti-dispersion cement soil is reduced by the pressure pump 33 of the pressurizing section 32, which reduces the time the cement soil stays in the conduit, prevents the condensation effect from being weakened, reduces the cracking phenomenon after the cement soil hardens, and can increase the efficiency of production.

[0085] Step 6, pressurization: the condensed mud is pressurized and discharged to the vicinity of the flushing pit of the fan foundation 37.

[0086] In the following embodiments, for the above-mentioned preferred underwater anti-dispersion cement soil, a fluidity test was performed to measure the expansion degree of the freshly mixed underwater anti-dispersion cement soil to reflect its fluidity, an anti-dispersion test was performed to measure the turbidity of the suspension of the underwater anti-dispersion cement soil after entering water to reflect its anti-dispersion performance, and an unconfined compressive strength test was performed to measure the unconfined compressive strength of the sample at a curing age of 28 days.

[0087] The cement soil used in the fluidity test, anti-dispersion test and 28d-age unconfined compressive strength test is preferably prepared by the above-mentioned underwater anti-dispersion cement soil preparation method.

[0088] Next, the prepared mud-like underwater anti-dispersion cement soil is cast and formed, which specifically includes the following steps:

[0089] Step S1, pouring: Before pouring, evenly apply a thin layer of mineral oil on the inner surface of the test mold to facilitate demoulding after molding. Fill the evenly stirred soil sample into the test mold in multiple layers.

[0090] Step S2, compaction: Use manual vibration to make the sample dense, and use a spatula to tamp at the same time. Scrape off the excess cement soil on the top of the test mold to make the surface flat and smooth, and then cover it with plastic film and let it stand.

[0091] Step S3, demoulding: the specimen is demoulded after standing at room temperature for 48 hours.

[0092] Step S4, curing: after demoulding, the specimens are placed in water for curing for 28 days, ensuring that the interval between the specimens is greater than 10 mm and the water surface is 20 mm higher than the specimens.

[0093] In this embodiment, the flow performance test of cement soil is carried out according to the JCT1023-2007 specification of "cement-based self-leveling mortar for ground", and the expansion is greater than 55.5mm; the anti-dispersion test of cement soil is carried out according to the SGZ-200B model turbidity meter, and the turbidity is less than 54NTU; the unconfined compressive strength of cement soil after 28d of curing is carried out according to the JTGE51-2009 specification of "Test Code for Stabilized Materials of Inorganic Binders for Highway Engineering", and the strength is greater than 210kPa.

[0094] like Fig. 9 As shown in Figure 10, the test results of the cement soil using the preferred ratio are: expansion 63.5mm, turbidity 39.9NTU, and unconfined compressive strength 245.1kPa, indicating that the underwater anti-dispersion cement soil prepared by this preferred ratio of cement soil has good fluidity, anti-dispersion and compressive strength.

[0095] The preferred embodiments of the present invention are described in detail above; however, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. An underwater anti-dispersion cement soil, characterized in that: Including waste soft clay, curing agent, water, anti-dispersant, fiber materials; among which: The curing agent is selected from ordinary Portland cement; The mass ratios of curing agent, anti-dispersion agent and fiber material to waste soft clay are 5% to 20%, 0.25‰ to 0.75‰ and 0.2% to 0.6% respectively; The water is 1.4 to 2 times the liquid limit of abandoned soft clay.

2. The underwater anti-dispersion cement soil according to claim 1, characterized in that: The waste soft clay is selected from marine silt clay or river silt clay.

3. The underwater anti-dispersion cement soil according to claim 1, characterized in that: The fiber material is polyester fiber, basalt fiber, glass fiber, polypropylene fiber, sisal fiber or polyvinyl alcohol fiber.

4. The underwater anti-dispersion cement soil according to claim 1, characterized in that: Anti-dispersant is a high molecular weight polymer.

5. The underwater anti-dispersion cement soil according to claim 4, characterized in that: The anti-dispersing agent is polyacrylamide, xanthan gum, ethylene-vinyl acetate copolymer or hydroxypropyl methylcellulose.

6. An underwater anti-dispersion cement soil preparation device, characterized in that: It includes a mixing barrel, a mixing blade, a reflux barrel and a suction device; An inclined mud separator is integrally provided at the bottom of the mixing barrel; The reflux barrel is coaxially arranged at the center of the mixing barrel and can rotate actively; there is a reflux gap between the bottom of the reflux barrel and the bottom of the mixing barrel, and a reflux port is arranged at the bottom of the reflux barrel; There are a plurality of stirring blades, which are evenly arranged along the circumference of the middle part of the reflux barrel and are all detachably connected to the reflux barrel; Each stirring blade has a fiber dispersing plane on the top, and each stirring blade is evenly provided with a number of fiber distributing holes; The suction device is arranged outside the mud separator and can suck the cement soil at the bottom of the mixing barrel to the top of the reflux barrel.

7. The underwater anti-dispersion cement soil preparation device according to claim 6, characterized in that: Also includes a condensing device; The condensing device is arranged on the mud outlet pipe at the bottom of the mixing barrel, and comprises a condenser, an inner condensing pipe, an outer condensing pipe and an insulation bin; The inner condenser pipe, the mud outlet pipe and the outer condenser pipe are coaxially arranged in sequence; and the inner condenser pipe is connected to the outer condenser pipe; The condenser is connected to the free ends of the inner condenser tube and the outer condenser tube respectively; The heat-insulating chamber is wrapped around the outer condenser pipe and the outer periphery of the condenser.

8. The underwater anti-dispersion cement soil preparation device according to claim 7, characterized in that: It also includes a pressure pump; the pressure pump is arranged on the mud outlet pipe downstream of the condensation device.

9. The underwater anti-dispersion cement soil preparation device according to claim 6, characterized in that: Each stirring blade is a rectangular blade arranged obliquely; and racks are arranged on the periphery of each stirring blade.

10. A method for preparing underwater anti-dispersion cement soil, characterized in that: The steps include: Step 1, spreading fiber material: first, all stirring blades are removed from the periphery of the reflux barrel; then, a set amount of fiber material is evenly spread on the fiber dispersion planes of all stirring blades; finally, the stirring blades spread with fiber material are sequentially installed on the periphery of the reflux barrel; Step 2, adding materials: add the set amount of waste soft clay, curing agent, water and anti-dispersant into the mixing barrel on the periphery of the return barrel in sequence; Step 3, stirring: the return barrel rotates actively, driving the stirring blade to rotate synchronously, and the fiber material spread on the stirring blade is evenly dispersed in the return barrel through the fiber distribution hole, and the waste soft clay, curing agent, water, anti-dispersant and fiber material are evenly mixed; Step 4, reflux: During the stirring process, a suction device is used to reflux the stirring mud at the bottom of the stirring barrel to the bottom of the reflux barrel; the stirring mud entering the reflux barrel refluxes from the reflux port at the bottom of the reflux barrel to the middle of the stirring barrel, and continues to be stirred evenly; Step 5, condensation: the mud material after reflux stirring is discharged from the mud outlet pipe and condensed by the condensation device; Step 6: Pressurize: discharge the condensed mud under pressure.

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