Soft soil solidification accurate mixing system and mixing method thereof

Abstract

The invention discloses a soft soil solidification accurate mixing system and a mixing method thereof. The mixing system comprises a conveying device, a smashing unit, a moisture content adjusting unit, a curing agent adding unit, a mixing device and a control unit. The smashing unit, the moisture content adjusting unit and the curing agent adding unit are sequentially arranged in the conveying direction, the discharging positions of the smashing unit, the moisture content adjusting unit and the curing agent adding unit correspond to the conveying device, the discharging position of the conveying device is connected with the mixing device, and the smashing unit, the moisture content adjusting unit, the curing agent adding unit, the conveying device and the mixing device are all in signal connection with the control unit. The crushing unit comprises a feeding bin, a first spiral conveyor, a cutting crusher and a soil moisture sensor arranged in the feeding bin. The mixing system can automatically calculate the type and dosage of the added soft soil treatment material according to the moisture content of the soft soil in the storage yard and accurately add the soft soil treatment material, it is guaranteed that the soft soil finally reaches the optimal moisture content and is fully solidified, and therefore the construction quality of soft soil solidification treatment is improved.

Description

Technical Field

[0001] The invention relates to the technical field of soft soil ex situ solidification disposal, and in particular to a system and a mixing method thereof suitable for adding a solidifying agent for mixing production when ex situ solidification of soft soil is performed. Background Art

[0002] The soft soil of the tidal flats in coastal areas is widely distributed and is a considerable land resource for coastal areas. However, the soft soil of the tidal flats generally has the characteristics of high water content, low shear strength and poor foundation bearing capacity, which makes it difficult to be directly used for urban construction. Solidifying the soft soil by adding a curing agent to improve its mechanical strength is a relatively mature way of improving soft soil, which has been applied in major engineering projects. The commonly used construction methods for soft soil solidification construction are road mixing method and factory mixing method. The road mixing method mainly spreads the abandoned soil and various curing materials on the road surface or backfill area with the help of mechanized operation of the road mixer. The factory mixing method refers to the construction method of setting up a fully enclosed centralized solidified soil mixing base, centralized crushing and mixing of the abandoned soil, and preparing solidified soil. The road mixing method is simple to construct, but there are also problems such as uneven mixing of the curing agent, incomplete crushing of the soil blocks, and large environmental pollution. It is currently being phased out. With the improvement of green and environmental protection construction requirements and the development of construction technology, a greener, more economical, efficient and adaptable factory mixing process has developed accordingly.

[0003] During the soft soil solidification construction process, it is necessary to add an appropriate amount of curing agent to the soft soil and mix it thoroughly. The mixed soil is then backfilled and compacted. Before mixing the curing agent, the soft soil needs to contain a certain amount of water to react with the curing agent, and at the same time, the moisture content of the improved soil after mixing needs to be controlled to be close to the optimal moisture content. The optimal moisture content is the basic property of the soil, which refers to the moisture content corresponding to the maximum dry density that the soil can reach under certain conditions. It is directly related to the compaction effect and engineering properties of the soil. In the foundation backfill construction, if the actual moisture content of the backfill soil is too high or too low relative to the optimal moisture content, the soil will not be fully compacted, thereby affecting the quality of the backfill construction. The optimal moisture content of the same type of soil is basically the same, and the optimal moisture content of soft soil is generally 15-25%. However, the soft soil excavated from the coastal tidal flats is usually piled in the open air. The moisture content of the soft soil in the yard is unevenly distributed, generally between 10% and 30%, and the surface layer has low moisture content, while the soft soil buried deep has high moisture content; the soft soil that has been piled for a long time has low moisture content, while the newly excavated soft soil has high moisture content. In addition, due to the tight construction schedule and limited site, the soft soil cannot be dried. Conventional methods cannot control the moisture content during the soft soil solidification process, which affects the solidification effect, resulting in poor soil solidification strength and even inability to backfill.

[0004] In response to the above problems, it is necessary to develop a soft soil solidification mixing production system and method, which can automatically calculate the type and amount of soft soil treatment materials to be added according to the moisture content of the soft soil, accurately add the mixing treatment materials, ensure that the soft soil reaches the optimal moisture content and is fully solidified, thereby improving the construction quality of soft soil solidification treatment. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the above-mentioned background technology and provide a soft soil solidification mixing production system and a mixing method thereof, which can automatically calculate the type and amount of soft soil treatment materials to be added according to the moisture content of the soft soil, accurately add the mixing treatment materials, ensure that the soft soil reaches the optimal moisture content and is fully solidified, thereby improving the construction quality of the soft soil solidification treatment.

[0006] The technical solution of the present invention is: a soft soil solidification precision mixing system, including a conveying device, a crushing unit, a moisture content adjustment unit, a solidifying agent adding unit, a mixing device, and a control unit;

[0007] The crushing unit, the moisture content adjustment unit, and the curing agent adding unit are arranged in sequence along the conveying direction, and the discharge points correspond to the conveying equipment. The discharge point of the conveying equipment is connected to the mixing equipment. The crushing unit, the moisture content adjustment unit, the curing agent adding unit, the conveying equipment, and the mixing equipment are all connected to the control unit by signal.

[0008] The pulverizing unit includes a feed bin, a first screw conveyor, a cutting pulverizer, and a soil moisture sensor disposed in the feed bin;

[0009] The moisture content adjustment unit includes a solid material storage tank and a clean water storage tank. The solid material storage tank outlet is provided with a second screw conveyor for adding solid material when the soft soil moisture content is too high. The clean water storage tank outlet is connected to an adjustable speed water pump for adding water when the soft soil moisture content is too low.

[0010] Preferably, the feed bin is funnel-shaped and the lower end is connected to the feed port of the first screw conveyor, the discharge port of the first screw conveyor is connected to the feed port of the cutting and crushing machine, and the soil moisture sensor is arranged in the lower part of the feed bin.

[0011] Preferably, the curing agent adding unit comprises a curing agent storage tank and a third screw conveyor, the bottom of the curing agent storage tank is conical and the discharge port of the curing agent storage tank is connected to the feed port of the third screw conveyor.

[0012] Preferably, the conveying equipment includes a conveyor belt, and the discharge points of the crushing unit, the moisture content adjustment unit, and the curing agent adding unit are all located directly above the conveyor belt; the mixing equipment includes a shaftless spiral mixing drum connected to the discharge point of the conveyor belt.

[0013] Furthermore, the control unit is connected to the soil moisture sensor signal to obtain the actual moisture content of the soft soil to be treated, the control unit is connected to the first screw conveyor, the second screw conveyor, the adjustable speed water pump, and the third screw conveyor signal to control the injection acceleration rate of the soft soil, solid material, clean water, and curing agent, and the control unit is connected to the conveying equipment and mixing equipment signal to control the material conveying.

[0014] The present invention also provides a mixing method of any of the above soft soil solidification precision mixing systems, comprising the following steps:

[0015] Predetermine three parameters: soft soil curing efficiency E, optimal moisture content B of the soft soil to be cured, and the mass percentage C of the curing agent relative to the soft soil;

[0016] The crushing unit transports the soft soil to the running conveying equipment according to the soft soil solidification processing efficiency E, and obtains the actual moisture content A of the soft soil through the soil moisture sensor;

[0017] The actual moisture content A is compared with the target moisture content D calculated using the parameters B and C. When A>D or A<D, the moisture content of the soft soil is adjusted through the moisture content adjustment unit. When A=D, no moisture content adjustment is required.

[0018] The curing agent adding unit adds curing agent powder to the soft soil according to the curing agent's added mass percentage C relative to the soft soil, and finally all the materials are mixed by the mixing equipment and then discharged.

[0019] Preferably, the target moisture content D is calculated according to D=B+K·C, wherein K is a correction coefficient and has a value of 0.4 to 0.6.

[0020] Preferably, when A>D, the adjustment of the soft soil moisture content includes: calculating the solid material addition rate Q1 by the following formula, and adding solid material to the soft soil on the conveying equipment according to Q1,

[0021]

[0022] Preferably, when A<D, the adjustment of the soft soil moisture content includes: calculating the clean water addition rate Q2 by the following formula, and adding water to the soft soil on the conveying equipment according to Q2,

[0023]

[0024] The above actual moisture content A, target moisture content D, and optimal moisture content B are all ratios of water mass / dry soil mass, which are conventional moisture content expressions in this field.

[0025] Preferably, the solid material is one or more of dry fine-grained construction waste, fly ash, and steel slag powder, and the particle size is controlled within 10 mm.

[0026] Aiming at the problem of difficulty in controlling moisture content and inaccurate addition of curing agent during soft soil curing construction, this patent has developed a precise mixing system and mixing method for soft soil curing, which has the following beneficial effects:

[0027] (1) In the precise mixing system for soft soil solidification, the conveying equipment conveys all materials, the crushing unit crushes the soft soil and the built-in soil moisture sensor senses the actual moisture content of the soft soil. The moisture content adjustment unit can add solid materials when the moisture content of the soft soil is too high, and can add water when the moisture content of the soft soil is too low, until the soft soil reaches the target moisture content. The mixing equipment mixes all materials (soft soil, solid materials / water, curing agent) evenly and then discharges them. The various components of the precise mixing system for soft soil solidification cooperate with each other, and can automatically calculate the type and amount of soft soil treatment materials to be added according to the moisture content of the soft soil in the yard and add them accurately, ensuring that the soft soil reaches the optimal moisture content and is fully solidified after mixing, thereby improving the construction quality of soft soil solidification treatment.

[0028] (2) The crushing unit includes a feed bin, a first screw conveyor, a cutting crusher, and a soil moisture sensor. The crushing unit can not only crush the soft soil and transport it to the conveying equipment according to the soft soil solidification treatment efficiency E, but also measure the moisture content of the soft soil to be treated in real time as a basis for subsequent moisture content adjustment.

[0029] (3) The moisture content adjustment unit includes a solid material storage tank and a clean water storage tank. The solid material storage tank is used to add solid material as required when the moisture content of the soft soil is too high through a second screw conveyor. The clean water storage tank is used to add water as required when the moisture content of the soft soil is too low through an adjustable speed water pump, thereby quickly and accurately adjusting the moisture content.

[0030] (4) The curing agent adding unit includes a curing agent storage tank and a third screw conveyor. The soft soil curing agent can be cement, quicklime, various commercial curing agents and other materials. The particle size is controlled within 100 mesh (0.15 mm). The third screw conveyor spreads the curing agent on the conveyor belt at a set acceleration rate C, so that the curing agent addition is completed conveniently and quickly.

[0031] (5) The mixing method of the present invention adopts a soft soil moisture content monitoring and automatic control method, which is suitable for soft soil solidification treatment within different moisture content ranges. The soft soil is adjusted to reach the target moisture content and then a curing agent is added for solidification, ensuring that the soft soil can always be close to the optimal moisture content after mixing.

[0032] (6) The automatic calculation method for the amount of each type of material added was clarified, and corresponding precise addition equipment was provided to improve the construction quality of soft soil solidification treatment.

[0033] (7) The entire system adopts the form of assembly line automated production, which significantly improves production efficiency while reducing costs and labor intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0036] Figure 1 Schematic diagram of the soft soil solidification precise mixing system of the present invention

[0037] Among them: 1-feeding bin, 2-first screw conveyor, 3-cutting crusher, 4-soil moisture sensor, 5-transmission equipment, 6-solid material storage tank, 7-second screw conveyor, 8-clean water storage tank, 9-adjustable speed water pump, 10-spray shower, 11-curing agent storage tank, 12-third screw conveyor, 13-shaftless spiral mixing drum feed port, 14-mixing equipment, 15-shaftless spiral mixing drum discharge port, 16-soft soil after mixing treatment, 17-control unit. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of this application. Unless otherwise specified, various raw materials and equipment used in this application can be purchased from the market or prepared by existing methods.

[0039] like Figure 1 As shown, the present invention provides a soft soil solidification precision mixing system, including a conveying device 5, a crushing unit, a moisture content adjustment unit, a curing agent adding unit, a mixing device 14, and a control unit 17; the crushing unit, the moisture content adjustment unit, and the curing agent adding unit are arranged in sequence along the conveying direction and the discharge points are all corresponding to the conveying device 5, the discharge point of the conveying device 5 is connected to the mixing device 14, and the crushing unit, the moisture content adjustment unit, the curing agent adding unit, the conveying device 5, and the mixing device 14 are all connected to the control unit 17 by signal. In this embodiment, the conveying direction is from front to back.

[0040] The crushing unit includes a feed bin 1, a first screw conveyor 2, a cutting crusher 3 and a soil moisture sensor 4 arranged in the feed bin 1; the moisture content adjustment unit includes a solid material storage tank 6 and a clean water storage tank 8. The discharge port of the solid material storage tank 6 is provided with a second screw conveyor 7 for adding solid materials when the moisture content of the soft soil is too high. The water outlet of the clean water storage tank 8 is connected to an adjustable speed water pump 9 for adding water when the moisture content of the soft soil is too low.

[0041] In some preferred embodiments, the conveying device 5 is a conveyor belt, and the discharge points of the crushing unit, the moisture content adjustment unit, and the curing agent addition unit are all located directly above the conveyor belt; the mixing device 14 is a shaftless spiral mixing drum connected to the discharge point of the conveyor belt.

[0042] In some preferred embodiments, the feed bin 1 is funnel-shaped and the lower end is connected to the feed port of the first screw conveyor 2 , the discharge port of the first screw conveyor 2 is connected to the feed port of the cutting and crushing machine 3 , and the soil moisture sensor 4 is arranged in the lower part of the feed bin 1 .

[0043] In some preferred embodiments, the specific control of the control unit 17 is as follows: the control unit 17 is connected to the soil moisture sensor 4 by signal to obtain the actual moisture content of the soft soil to be treated; the control unit 17 is connected to the first screw conveyor 2, the second screw conveyor 7, the adjustable speed water pump 9, and the third screw conveyor 12 by signal to control the injection rate of soft soil, solid material, clean water, and curing agent; the control unit is connected to the conveying equipment 5 and the mixing equipment 14 by signal to control material conveying.

[0044] Based on a general inventive concept, the present invention also provides a mixing method of the above soft soil solidification precise mixing system:

[0045] Step S1: Determine the soft soil curing efficiency E (unit: t / h), the optimal moisture content B of the soft soil to be cured, and the mass percentage C of the curing agent relative to the soft soil (i.e., the external admixture amount) through indoor experiments, and input these three parameters into the control unit 17.

[0046] Step S2: The control unit 17 controls the conveyor belt and the shaftless spiral mixing drum to start. Use mechanical equipment such as an excavator or a loader to pour the soft soil into the feed port of the feed bin 1. The feed bin 1 is conical, and a soil moisture sensor is installed near the lower discharge port, which can measure the actual moisture content A of the soft soil to be treated in real time and feed the data back to the control unit 17. A first horizontal screw conveyor 2 is connected to the bottom of the feed bin. The control unit 17 adjusts the soft soil conveying rate of the first screw conveyor 2 according to the input soft soil curing treatment efficiency E (t / h). The soft soil is transmitted to the cutting and crushing machine 3 through the first screw conveyor 2 to cut and crush the soft soil. The crushed soft soil falls onto the conveyor belt below and is transported to the next link.

[0047] Step S3: The control unit 17 calculates the target moisture content D according to formula (1). After obtaining the actual moisture content A of the soft soil, it will be compared with the target moisture content D. When A>D, the moisture content of the soft soil is too high, and step a is executed; when A<D, the moisture content of the soft soil is too low, and step b is executed; when A=D, no moisture content adjustment is required, that is, the entire moisture content adjustment unit does not need to be operated.

[0048] D=B+K·C (1)

[0049] Among them, K is the correction coefficient, which ranges from 0.4 to 0.6.

[0050] Step a: The control unit 17 calculates the solid material addition rate Q1 according to formula (2), and the second screw conveyor 7 below the solid material storage tank 6 conveys the solid material to the conveyor belt at this rate to reduce the soft soil moisture content to the target moisture content D. The solid material can be dry fine-grained construction waste, fly ash, steel slag powder and other cheap and non-toxic inorganic solid waste materials, and the particle size is controlled within 10 mm.

[0051]

[0052] Step b: The clean water addition rate Q2 is calculated according to formula (3), and the adjustable speed water pump 9 below the clean water storage tank 8 delivers and sprays clean water onto the conveyor belt at this rate to increase the soft soil moisture content to the target moisture content D.

[0053]

[0054] Step S4: The soft soil that has passed through the crushing unit and the moisture content adjustment unit is further transported backwards through a conveyor belt. A curing agent storage tank 11 and a third screw conveyor 12 connected thereto are provided on one side of the conveyor belt. The third screw conveyor 12 transports curing agent powder onto the conveyor belt according to the set curing agent dosage C.

[0055] Step S5: the soft soil mixed with the curing agent powder is transported to the shaftless spiral mixing drum through a conveyor belt. The shaftless spiral mixing drum rotates continuously and transports the soft soil backward. Under the action of the mixing drum, the soft soil and the curing agent and other treatment materials are evenly mixed. Finally, the soft soil is discharged from the discharge port of the shaftless spiral mixing drum for stacking or loading and transportation. The soft soil mixing process is completed to obtain the mixed soft soil 16.

[0056] The present application is further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and are not used to limit the scope of the present application.

[0057] Example 1

[0058] During the construction of the house foundation, the project excavated about 100,000 cubic meters of soft soil, which was temporarily piled up in the abandoned soil yard in the construction area, with a stacking height of about 2 to 3 meters. In order to achieve resource reuse, it is planned to solidify the soft soil and use it for foundation and slope backfill. After testing, the soft soil composition of the yard is consistent, with an optimal moisture content of 20%. The measured moisture content of the surface soft soil of the yard is about 15%, and the moisture content of the soft soil below 1m is about 20%. There are intermittent piles of newly excavated soft soil, with a high moisture content of about 25%. The moisture content of the soft soil in the entire yard is uneven, which is somewhat different from the optimal moisture content. Directly adding a curing agent will result in uneven curing effect and difficult to control the compaction process. In order to ensure the quality of soft soil solidification backfill, a soft soil solidification precision mixing system described in this patent is adopted.

[0059] like Figure 1 As shown, a soft soil solidification precision mixing system is composed of the following parts: a conveying device 5, a crushing unit, a moisture content adjustment unit, a solidifying agent adding unit, a mixing device 14, and a control unit 17.

[0060] The crushing unit, moisture content adjustment unit, and curing agent adding unit are arranged in sequence along the conveying direction and the discharge points correspond to the conveying equipment 5. The discharge point of the conveying equipment 5 is connected to the mixing equipment 14. The crushing unit, moisture content adjustment unit, curing agent adding unit, conveying equipment 5, and mixing equipment 14 are all connected to the control unit 17 signal.

[0061] In this embodiment, the conveying device 5 is a conveyor belt, the mixing device 14 is a shaftless spiral mixing drum, and the discharge of the conveying device 5 is connected to the feed port of the shaftless spiral mixing drum. The conveyor belt is laid directly below the discharge ports of the crushing unit, the moisture content adjustment unit, and the curing agent adding unit, and the crushing unit, the moisture content adjustment unit, and the curing agent adding unit add materials to the conveying device 5 in sequence along the conveying direction.

[0062] The crushing unit includes a feed bin 1, a first screw conveyor 2, a soil moisture sensor 4 and a cutting crusher 3. The feed bin 1 is funnel-shaped, and the upper feed port is used to receive the soft soil to be treated added by an excavator or a loader. A soil moisture sensor 4 is installed near the lower discharge port of the feed bin 1, which can measure the moisture content of the soft soil to be treated in real time. The lower discharge port of the feed bin 1 is connected to a horizontal first screw conveyor 2. The first screw conveyor 2 has a screw conveying shaft, and the soft soil conveying rate can be accurately adjusted by controlling the rotation speed of the screw conveying shaft. A cutting crusher 3 is connected below the discharge port of the first screw conveyor 2, and the cutting crusher 3 has two horizontal rotating shafts, on which a number of cutting tools are evenly installed. When the cutting crusher 3 is running, the horizontal rotating shaft rotates at a high speed to achieve cutting and crushing of the soft soil.

[0063] The moisture content adjustment unit includes a solid material storage tank 6, a second screw conveyor 7, a clean water storage tank 8, an adjustable speed water pump 9, and a spray shower 10. The solid material storage tank 6 is located after the cutting and crushing machine of the crushing unit, is cylindrical, and stores dry solid materials inside. The solid material can be dry fine-grained construction waste, fly ash, steel slag powder and other cheap, non-toxic, inorganic solid waste materials, and the particle size is controlled within 10 mm. The bottom of the solid material storage tank 6 is conical, and the outlet is connected to the second screw conveyor 7. The second screw conveyor 7 spreads solid materials on the conveyor belt at a set acceleration rate, thereby reducing the moisture content of the soft soil. The clean water storage tank 8 is located after the solid material storage tank 6, and stores clean water inside. There is an adjustable speed water pump 9 at the bottom of the clean water storage tank 8, which can control the flow rate of clean water output from the clean water storage tank 8. The adjustable speed water pump 9 is connected to the spraying shower 10 through a water pipe. The spraying shower 10 is located above the conveyor belt and can evenly spray clean water on the soft soil conveyed, thereby increasing the moisture content of the soft soil.

[0064] The curing agent adding unit includes a curing agent storage tank 11 and a third screw conveyor 12. The curing agent storage tank 11 is located after the moisture content adjustment unit, is cylindrical, and stores soft soil curing agent inside. The soft soil curing agent can be materials such as cement, quicklime, and various commercial curing agents, and the particle size is controlled within 100 mesh (0.15mm). The bottom of the curing agent storage tank 11 is conical, and the outlet is connected to the third screw conveyor 12. The third screw conveyor 12 spreads the curing agent on the conveyor belt at a set injection acceleration rate to complete the curing agent addition.

[0065] The mixing equipment 14 includes a shaftless spiral mixing drum. The shaftless spiral mixing drum is provided with a shaftless spiral mixing drum feed port 13 and a shaftless spiral mixing drum discharge port 15. The shaftless spiral mixing drum feed port 13 is connected to the end of the conveyor belt to receive the soft soil after adding the treatment material. The inner wall of the shaftless spiral mixing drum is provided with spiral blades. The drum body rotates under the drive of the motor to transport the soft soil and the treatment material backward. At the same time, the soft soil and the treatment material are fully stirred and mixed during the transportation process to complete the mixing process of the soft soil with the curing agent. The fully mixed soft soil is discharged from the shaftless spiral mixing drum discharge port 15, and the mixed soft soil 16 is obtained.

[0066] The control unit 17 is connected to the soil moisture sensor 4, the adjustable speed water pump 9, each screw conveyor (the first screw conveyor 2, the second screw conveyor 7, the third screw conveyor 12), the shaftless screw mixing drum, and the conveyor belt signal through wired or wireless transmission. The control unit 17 obtains the actual moisture content of the soft soil to be processed through the soil moisture sensor 4, controls the injection rate of the soft soil, solid materials, clean water, and curing agent through the first screw conveyor 2, the second screw conveyor 7, the adjustable speed water pump 9, and the third screw conveyor 12, realizes material transmission by controlling the operation of the conveyor belt, and mixes and discharges the materials by controlling the rotation speed of the shaftless screw mixing drum. The control unit 17 controls the operation of the entire equipment.

[0067] Example 2

[0068] This embodiment provides a mixing method of the above soft soil solidification precise mixing system, the steps are as follows:

[0069] Through indoor tests, the optimal moisture content of the soft soil to be cured is B=20%, the mass percentage of the curing agent relative to the soft soil is C=4%, and the soft soil curing efficiency is E=1 (t / h). These three parameters are input into the control unit 17 of the central control unit.

[0070] The conveyor belt and the shaftless spiral mixing drum are started. Use mechanical equipment such as an excavator or a loader to pour the soft soil into the feed port of the feed bin 1. A soil moisture sensor 4 is installed near the lower discharge port of the feed bin 1, which can measure the actual moisture content A of the soft soil to be treated in real time and feed the data back to the control unit 17. There is a horizontal first screw conveyor 2 at the bottom of the feed bin 1. The central control unit adjusts the soft soil conveying rate of the first screw conveyor 2 to 1t / h based on the input soft soil curing treatment efficiency E=1 (t / h). The soft soil is transmitted to the cutting and crushing machine 3 through the first screw conveyor 2. The crushed soft soil falls onto the conveyor belt below and is transported to the next link.

[0071] The control unit 17 calculates the target moisture content D=21.6% (correction coefficient K=0.4) according to formula (1). After obtaining the actual moisture content A of the soft soil, it compares it with the target moisture content D and takes corresponding steps.

[0072] D=B+K·C (1)

[0073] For example, when the actual moisture content A=25.0%>D, the moisture content of the soft soil is too high, and the following steps are performed: According to formula (2), the solid material addition rate Q1=125.9 (kg / h) is calculated, and the second screw conveyor 7 under the solid material storage tank 6 conveys the solid material to the conveyor belt according to Q1 to reduce the moisture content of the soft soil to the target moisture content D. The solid material can be dry fine-grained construction waste, fly ash, steel slag powder and other cheap non-toxic inorganic solid waste materials, and the particle size is controlled within 10 mm.

[0074]

[0075] When A=15.0%<D, the moisture content of the soft soil is too low, and the following steps are performed: According to formula (3), the clean water addition rate Q2=57.4 (kg / h) is calculated, and the adjustable speed water pump 9 under the clean water storage tank 8 transports and sprays clean water onto the conveyor belt according to Q2 to increase the moisture content of the soft soil to the target moisture content D.

[0076]

[0077] The soft soil after crushing and moisture content adjustment is further transported backward through a conveyor belt. A curing agent storage tank 11 and a third screw conveyor 12 connected thereto are arranged on one side of the conveyor belt. The third screw conveyor 12 transports curing agent powder onto the conveyor belt according to the set curing agent dosage C=4%.

[0078] The soft soil mixed with the curing agent powder is transported to the shaftless spiral mixing drum through a conveyor belt. The shaftless spiral mixing drum rotates continuously and transports the soft soil backward. Under the action of the mixing drum, the soft soil is evenly mixed with the curing agent and other treatment materials, and finally discharged from the discharge port 15 of the shaftless spiral mixing drum for stacking or loading and transportation, completing the soft soil mixing process and obtaining the mixed soft soil 16.

Claims

1. A soft soil solidification precision mixing system, characterized in that: It comprises a conveying device (5), a crushing unit, a moisture content adjustment unit, a curing agent adding unit, a mixing device (14), and a control unit (17); The crushing unit, the moisture content adjustment unit, and the curing agent adding unit are arranged in sequence along the conveying direction, and the discharge points correspond to the conveying device (5); the discharge point of the conveying device (5) is connected to the mixing device (14); and the crushing unit, the moisture content adjustment unit, the curing agent adding unit, the conveying device (5), and the mixing device (14) are all connected to the control unit (17) by signal. The pulverizing unit comprises a feed bin (1), a first screw conveyor (2), a cutting pulverizer (3), and a soil moisture sensor (4) arranged in the feed bin (1); The moisture content adjustment unit comprises a solid material storage tank (6) and a clean water storage tank (8); the solid material storage tank (6) has a discharge port provided with a second screw conveyor (7) for adding solid material when the moisture content of the soft soil is too high; the clean water storage tank (8) has a water outlet connected with an adjustable speed water pump (9) for adding water when the moisture content of the soft soil is too low.

2. The soft soil solidification precise mixing system according to claim 1, characterized in that: The feed bin (1) is funnel-shaped and its lower end is connected to the feed port of the first screw conveyor (2); the discharge port of the first screw conveyor (2) is connected to the feed port of the cutting and crushing machine (3); and the soil moisture sensor (4) is arranged in the lower part of the feed bin (1).

3. The soft soil solidification precise mixing system according to claim 1, characterized in that: The curing agent adding unit comprises a curing agent storage tank (11) and a third screw conveyor (12); the bottom of the curing agent storage tank (11) is conical and the discharge port of the curing agent storage tank (11) is connected to the feed port of the third screw conveyor (12).

4. The soft soil solidification precise mixing system according to claim 1, characterized in that: The conveying device (5) comprises a conveyor belt, and the discharge points of the crushing unit, the moisture content adjustment unit, and the curing agent addition unit are all located directly above the conveyor belt; the mixing device (14) comprises a shaftless spiral mixing drum connected to the discharge point of the conveyor belt.

5. The soft soil solidification precise mixing system according to claim 3, characterized in that: The control unit (17) is connected to the soil moisture sensor (4) by signal so as to obtain the actual moisture content of the soft soil to be processed; the control unit (17) is connected to the first screw conveyor (2), the second screw conveyor (7), the adjustable speed water pump (9) and the third screw conveyor (12) by signal so as to control the injection rate of the soft soil, solid material, clean water and curing agent; the control unit (17) is connected to the conveying equipment (5) and the mixing equipment (14) by signal so as to control the material transmission.

6. A mixing method of any one of claims 1 to 5 as a precise mixing system for solidifying soft soil, characterized in that: The following steps are involved: Predetermine three parameters: soft soil curing efficiency E, optimal moisture content B of the soft soil to be cured, and the mass percentage C of the curing agent relative to the soft soil; The crushing unit transports the soft soil to the running conveying equipment (5) according to the soft soil solidification processing efficiency E, and obtains the actual moisture content A of the soft soil through the soil moisture sensor (4); The actual moisture content A is compared with the target moisture content D calculated using the parameters B and C. When A>D or A<D, the moisture content of the soft soil is adjusted through the moisture content adjustment unit. When A=D, no moisture content adjustment is required. The curing agent adding unit adds curing agent powder to the soft soil according to the curing agent addition mass percentage C relative to the soft soil, and finally all the materials are mixed and discharged through the mixing device (14).

7. The mixing method of the soft soil solidification precision mixing system according to claim 6, characterized in that: The target moisture content D is calculated according to D=B+K·C, where K is the correction coefficient, with a value of 0.4 to 0.

6.

8. The mixing method of the soft soil solidification precision mixing system according to claim 6, characterized in that: When A>D, the adjustment of the soft soil moisture content includes: calculating the solid material addition rate Q1 by the following formula, adding solid material to the soft soil on the conveying device (5) according to Q1, 9. The mixing method of the soft soil solidification precision mixing system according to claim 6, characterized in that: When A<D, the adjustment of the soft soil moisture content includes: using the following formula to calculate the clean water addition rate Q2, and adding water to the soft soil on the conveying device (5) according to Q2, 10. The mixing method of the soft soil solidification precision mixing system according to claim 8, characterized in that: The solid material is one or more of dry fine-grained construction waste, fly ash, and steel slag powder, and the particle size is controlled within 10 mm.

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