Super-thick sludge shallow layer in-situ curing construction method and automatic quantitative feeding system

Abstract

The invention discloses an ultra-thick sludge shallow in-situ curing construction method and an automatic quantitative feeding system.The method comprises the steps that S100, additional drainage measures are taken for a high-water-level ultra-thick sludge area to lower the water level, and temporary construction roads, hydroelectric facilities and living and office facilities are built; the method comprises the following steps: S300, setting the proportion of a curing agent through an automatic quantitative curing agent feeding system, and carrying out an in-situ curing process test: S300, vertically inserting deep insertion type stirring equipment into a sludge layer for stirring and sinking, and spraying the curing agent; s400, after the stirring equipment sinks to the designed deep bottom, the stirring equipment temporarily stays and stirs and sprays a curing agent, and S400, after in-situ curing, curing is conducted for not less than 7 days, after 28 days, strength detection is conducted on a cured area, and it is ensured that the bearing capacity of the cured soil is not smaller than 100 KPa. Different curing agents are mixed and cut into a soil body through high-pressure jetting of the communicated nozzles in the stirring head, and the curing effect is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of foundation treatment, and more specifically, relates to an in-situ solidification construction method for a shallow layer of ultra-thick sludge and an automatic quantitative feeding system. Background Art

[0002] At present, there are three main methods of sludge solidification both internationally and domestically: physical dehydration, heating sintering and curing agent. The first two are suitable for occasions with small processing volume and high processing degree. The most economical and fastest way to treat large amounts of sludge is sludge solidification. After testing the water content and other substance content of silt and silty soil, different amounts of solidifying materials are added to the silt and silty soil according to different needs. After mixing, pre-pressing and curing, the solidified soil reaches the design bearing capacity.

[0003] The most common construction process for sludge solidification is in-situ solidification and sludge excavation and transportation to a sludge fixation treatment plant for solidification treatment. For example, patent document CN 106836186 A discloses a construction process for sludge solidification soil, including surface clearing and drainage, sludge sampling, detection and analysis, excavation and stacking, stirring and mixing, filling and rolling, and solidified soil maintenance steps. Through the in-situ solidification of the solidified soil, the sludge and the curing agent are stirred and mixed to form the sludge solidified soil, and the curing agent is made of expanded graphite, activated carbon, cement, quicklime, gypsum, wood cellulose, fly ash, granulated blast furnace slag powder, coal gangue, alkali slag, hydroxypropyl methylcellulose, furfural slag, medical stone and montmorillonite clay. In addition, patent document CN 103352460B discloses a layered soft foundation treatment construction process, which first uses a manual or mechanical method to dig out the space required for the project, and then mixes the excavated in-situ soft soil with a sludge curing agent to make it evenly mixed, thereby increasing the anti-seepage and water-stopping functions of the soil; the layered construction process is: first, a layer of curing agent is laid at the bottom of the excavated space, and then the stirred soil is laid in layers on the curing agent layer, and each layer of the stirred soil is flattened using a flattening device, and then another layer of the stirred soil is laid, and 2 to 5 layers of the stirred soil are laid, and the thickness of the laid stirred soil is 30 cm; the sludge curing agent includes powder and liquid raw materials, and the powder includes cement clinker, slag or slag, lime, gypsum, and sulfate; the liquid includes polyacrylamide, polyaluminum chloride, mannitol, lignin sulfonate, alkylphenol polyoxyethylene ether, tannic acid, humate, α-olefin sulfonate, etc.

[0004] The existing technology solves some problems that silt contains toxic chemicals, pathogenic organisms and other harmful components, and direct burial will not only occupy a large amount of arable land, but also pollute the environment. However, the silt is excavated and transported to the silt solidification treatment plant for solidification treatment, which increases the cost of excavation and transportation, wastes manpower, material resources and resources, and also requires the construction of silt solidification yards and solidification plants, occupying land resources; the existing in-situ solidification technology is mostly applicable to river silt treatment, silt layer treatment at road construction and in-situ solidification technology of offshore public facilities. At this stage, land resources are becoming increasingly tight, and coastal urban construction is accelerating the development and utilization of ultra-thick silt muddy soil beaches. The existing silt in-situ solidification technology does not meet the requirements of large-scale, large-volume and ultra-thick silt shallow in-situ solidification construction, and wastes manpower, material resources, financial resources and resources, increasing the cost of solidification treatment. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides an ultra-thick sludge shallow layer in-situ solidification construction method and an automatic quantitative feeding system, which generates a pressure chamber through an air compressor and an air collecting device, and distributes the pressure to a first storage tank and a second storage tank respectively, and transports the tank materials to the three-way valves respectively. The three-way valves mix different curing agents, and at the same time utilize the boosting force generated by the booster to transport the curing agent mixture through the nozzle of the mixing head and spray it out, thereby ensuring the actual curing effect on site, reducing the curing cost, and speeding up the construction speed.

[0006] In order to achieve the above object, according to the first aspect of the present invention, there is provided a method for in-situ solidification of a shallow layer of ultra-thick sludge, which is suitable for a high water level and low bearing capacity sludge environment, and is characterized in that it comprises the following steps:

[0007] S100: On-site pretreatment: Clean the solidification area, remove stagnant water, vegetation, rocks and garbage, take additional drainage measures to lower the water level in areas with high water levels and extra-thick silt, and build temporary construction roads, water and electricity facilities, and living and office facilities to ensure smooth access to the site and construction conditions for solidification equipment, materials and personnel;

[0008] S200: Determine the curing agent ratio: According to the treatment depth of the curing area, the water content and compression coefficient of the sludge, the curing agent ratio is set through the curing agent automatic quantitative feeding system, and a small-scale in-situ curing process test is carried out. The injection amount and ratio of the curing agent are dynamically adjusted according to the test results to ensure that the curing agent and the sludge are evenly mixed to meet the strength requirements;

[0009] S300: In-situ curing construction: Use deep insertion mixing equipment to vertically insert into the silt layer to stir and sink and spray the curing agent; after the mixing equipment sinks to the designed depth, it will stop briefly and stir and spray the curing agent, then stir and lift, and repeat the above actions once; continue stirring and spraying when the equipment is lifted to ensure that the curing agent and silt are fully mixed. After the regional curing is completed, an overlap area of ​​not less than 12 cm is formed in the adjacent curing areas to avoid curing omissions, so as to ensure the continuity after curing, and finally solidify to form an overall uniform hard shell layer;

[0010] S400: Maintenance and testing: After in-situ solidification, maintenance shall be carried out for no less than 7 days. During this period, measures such as zoned drainage system and covering protective film shall be adopted to prevent the influence of rain and cold weather on the solidification effect; after 28 days, the solidification area shall be tested for strength to ensure that the bearing capacity of the solidified soil is not less than 100KPa.

[0011] Furthermore, the automatic quantitative feeding system for the curing agent in S200 dynamically adjusts the injection amount and stirring frequency of the curing agent according to the depth, water content and compressibility of the sludge to achieve uniform mixing of the curing agent and the sludge.

[0012] Furthermore, the stirring device stirs and sinks and sprays the curing agent, stirs and sinks to the designed depth and then stays for a short time, then stirs and rises, to ensure that the curing agent is evenly distributed and to form a stirring overlap zone of not less than 12 cm in adjacent areas to avoid curing omissions.

[0013] According to a second aspect of the present invention, there is provided an automatic quantitative feeding system, comprising a feeding mechanism for providing air pressure and curing material and a quantitative feeding mechanism for accurately controlling the delivery and mixing of curing agent; wherein,

[0014] The feeding mechanism includes an air compressor, an air collecting device, a first air filter, a second air filter, a third air filter, a pressure chamber, and a first storage tank and a second storage tank, wherein the air compressor and the air collecting device are connected through a pipeline to generate compressed air and transport it to the pressure chamber, the pressure chamber is connected to the first storage tank through the second air filter, and is connected to the second storage tank through the third air filter, the first storage tank and the second storage tank are connected through a three-way valve for mixing the curing agent in the storage tanks, and a booster is provided between the pressure chamber and the three-way valve;

[0015] The quantitative feeding mechanism includes a first air inlet valve, a second air inlet valve, a first feed port, a second feed port, a first paddle-rotary material level controller and a second paddle-rotary material level controller for controlling the precise supply of the curing agent, which are used to adjust the amount of each feed and the spraying time to ensure that the curing agent is accurately mixed according to a preset ratio, and is driven by compressed air generated by an air compressor and an air collecting device, and the mixed curing agent is transported to the stirring equipment through a three-way valve for injection under the action of a booster.

[0016] Furthermore, the first storage tank and the second storage tank respectively include a pressure gauge, a discharge port and an annular air inlet, wherein the first pressure gauge of the first storage tank is arranged at the top of the first storage tank, the first feed port is located at the top of the first storage tank, the first discharge port is located at the bottom of the first storage tank, and the first rotary paddle level controller and the first annular air inlet are located on the side of the first storage tank.

[0017] Furthermore, the second storage tank has a similar structure, including a second pressure gauge arranged on the top of the second storage tank, a second feed port located at the top of the second storage tank, a second discharge port located at the bottom of the second storage tank, and a second rotary level controller and a second annular air inlet located on the side of the second storage tank.

[0018] Furthermore, the air compressor is of variable frequency type.

[0019] Furthermore, a digital touch screen is provided, which includes pressure, delivery volume and the switch state of the air inlet valve, and displays and controls the delivery process of the curing agent.

[0020] Furthermore, the quantitative feeding mechanism includes a first air inlet valve, a first feed port, and a first rotary paddle level controller.

[0021] Furthermore, the quantitative feeding mechanism includes a second air inlet valve, a second feed port and a second rotary resistance material level controller.

[0022] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0023] 1. The method of the present invention generates a pressure chamber through an air compressor and an air collecting device, distributes the pressure to the first storage tank and the second storage tank respectively, delivers the tank materials to the three-way valve respectively, and uses the booster to deliver the mixed curing agent to the curing treatment site in the three-way valve. The actual curing effect on site is guaranteed, the curing cost is reduced, and the construction speed is accelerated.

[0024] 2. The method of the present invention increases detailed control over the on-site solidification division area and adopts a solidification-while-advancing method to avoid solidification omissions. It is suitable for in-situ solidification construction of ultra-thick silt and shallow silt under large areas, large volumes, various conditions and ranges, and solidification coverage is guaranteed.

[0025] 3. The method of the present invention controls the first discharge port, the second discharge port and the first air inlet valve, the second air inlet valve and the air inlet valve switch of each discharge port automatically to ensure the amount of curing agent in each stirring interval, thereby ensuring the amount of curing agent in the entire block; remote operation can be realized to realize the automation and intelligence of curing agent spraying, save human resources, and avoid human-caused waste of resources; multiple first discharge ports and second discharge ports spray materials at the same time to ensure the proportion of curing agents in the stirring process and realize quantitative and accurate feeding.

[0026] 4. The method of the present invention uses the first annular air inlet and the second annular air inlet to loosen the solidified material in the tank to prevent the solidified material in the tank from accumulating and blocking the air inlet pipe. The feeding room is provided with a quantitative feeding device digital touch screen, which displays the curing agent in two parts: the control area and the recording area, and can control the pressure, the delivery amount, and the first air inlet valve, the second air inlet valve, and the air inlet valve switch during the curing agent delivery process in real time.

[0027] 5. The system of the present invention supports remote operation, and the operator can manage the curing agent spraying automatically and intelligently through the remote device. This design not only saves labor costs, but also avoids the waste of resources caused by human errors. The design of multiple discharge ports enables the system to perform multiple spraying operations at the same time, ensuring the continuity and efficiency of the construction process, which is particularly suitable for large-scale engineering construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a process flow chart of a shallow layer in-situ solidification construction method for ultra-thick sludge according to an embodiment of the present invention;

[0029] Figure 2 Schematic diagram of an automatic quantitative feeding system in an embodiment of the present invention;

[0030] Figure 3 Schematic diagram of area division in an embodiment of the present invention.

[0031] In all the drawings, the same figure marks represent the same technical features, specifically: 1-air compressor, 2-air collecting device, 3-first air filter, 4-pressure chamber, 5-second air filter, 6-third air filter, 7-first storage tank, 71-first air inlet valve, 72-first pressure gauge, 73-first feed port, 74-first rotary paddle level controller, 75-first annular air inlet, 76-first outlet, 8-second storage tank, 81-second air inlet valve, 82-second pressure gauge, 83-second feed port, 84-second rotary paddle level controller, 85-second annular air inlet, 86-second outlet, 9-three-way valve, 10-booster. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] Example 1

[0034] like Figure 1 As shown, an automatic quantitative feeding system is provided in an embodiment of the present invention, which includes a feeding mechanism and a quantitative feeding mechanism, wherein the feeding mechanism is responsible for providing the system with curing materials, and the quantitative feeding mechanism ensures that the curing agent can be mixed and transported in a precise proportion to ensure the effect of on-site construction. The core design of the system is to promote the transportation and mixing of the curing agent by air pressure, and adopt a series of precision control devices to ensure the efficiency and accuracy of the whole process. Among them, the feeding mechanism is composed of components such as an air compressor 1, an air collecting device 2, a first air filter 3, a pressure chamber 4, a first storage tank 7, and a second storage tank 8. The air compressor 1 and the air collecting device 2 are responsible for providing air pressure to the system to form a pressure chamber 4. The function of the pressure chamber is to transport compressed air to the first storage tank 7 and the second storage tank 8 respectively, so that the curing agent in the storage tank can be transported to the next link of the system by pressure. In order to ensure the cleanliness of the air, the system is designed with multiple air filters at different positions, such as the first air filter 3, the second air filter 5 and the third air filter 6. The function of these filters is to remove impurities in the compressed air to prevent them from entering the storage tank or the pressure chamber, affecting the transmission and spraying of the curing agent.

[0035] In an embodiment of the present invention, two sets of parallel structures are designed for the storage tank, namely the first storage tank 7 and the second storage tank 8, and the structures of the two are similar. Among them, the top of the first storage tank 7 is equipped with a first pressure gauge 72 for real-time monitoring of the pressure in the tank, and the bottom of the tank body is provided with a first discharge port 76, through which the solidified material is transported to the subsequent links. The first annular air inlet 75 on the side is used to evenly transport compressed air to prevent the curing agent in the tank from being blocked. Similarly, the second storage tank 8 is also equipped with the same structure, including a second pressure gauge 82, a second discharge port 86 and a second annular air inlet 85. Through these designs, the system can ensure that the solidified material in the storage tank can be smoothly discharged and transported to the three-way valve 9 for the next step of processing.

[0036] In the process of delivering the curing agent, the three-way valve 9 plays a vital role. The first discharge port 76, the second discharge port 86 and the booster 10 are all connected by the three-way valve, which is responsible for mixing the curing agents from the two storage tanks according to a predetermined ratio. At the same time, the driving force generated by the booster 10 can ensure that the curing agent mixture is sprayed out at a uniform speed and pressure, ensuring the injection rate and injection amount of the curing material. This design not only improves the material utilization rate and reduces material waste, but also speeds up the construction progress and reduces the construction period and cost.

[0037] In order to further improve the accuracy and automation level of the system, the system uses a variable frequency air compressor 1, which can adjust the air pressure according to actual needs to prevent excessive consumption of materials or air pollution. In addition, the system is also designed with a curing material loosening device at the first annular air inlet 75 and the second annular air inlet 85 to ensure that the curing material will not be deposited due to long-term storage, thereby avoiding the blockage of the air inlet pipe. The automatic quantitative feeding system is equipped with a digital touch screen, which can display the key parameters of the curing agent delivery process in real time, such as pressure, delivery volume, and the switch status of the first air inlet valve 7 and the second air inlet valve 81. Through the touch screen, the operator can control the supply process of the curing agent in real time and flexibly adjust various parameters according to the on-site conditions. This intelligent control system can greatly reduce manual intervention, improve construction efficiency, and reduce errors caused by human operation.

[0038] The quantitative feeding mechanism plays a vital role in ensuring the accuracy of feeding. The mechanism includes a first air inlet valve 71, a first feed port 73, a first rotary-type material level controller 74, and a corresponding second air inlet valve 81, a second feed port 83 and a second rotary-type material level controller 84. These controllers are responsible for monitoring the material level in the storage tank to ensure the precise control of the discharge amount and discharge time, and can also display and record the amount of material used in each area. By controlling the switch status of each discharge port and air inlet valve in real time, the system can accurately grasp the amount of curing agent in each stirring interval, avoid waste or insufficiency, and ensure the precise control of the curing agent ratio during the stirring process. The system supports remote operation, and the operator can use remote equipment to automatically and intelligently manage the curing agent spraying. This design not only saves labor costs, but also avoids the waste of resources caused by human errors. The design of multiple discharge ports enables the system to perform multiple spraying operations at the same time, ensuring the continuity and efficiency of the construction process, which is particularly suitable for large-scale engineering construction.

[0039] Example 2

[0040] Specifically, the first storage tank 7 and the second storage tank 8 have similar structures, wherein the first storage tank 7 includes a first pressure gauge 72, a first feed port 73, a first discharge port 76, a first rotary level controller 74 and a first annular air inlet 75; the first pressure gauge 72 and the first feed port 73 are arranged at the top of the first storage tank, the first discharge port 76 is arranged at the bottom of the first storage tank 7, and the side thereof is provided with a first rotary level controller 74 and a first annular air inlet 75.

[0041] The second material storage tank 8 includes a second pressure gauge 82, a second feed port 83, a second discharge port 86, a second rotary level indicator 84 and a second annular air inlet 85. The second pressure gauge 82 and the second feed port are arranged on the top of the second material storage tank 8, and the second discharge port 86 is arranged on the bottom of the second material storage tank 8, and the second rotary level indicator 84 and the second annular air inlet 85 are arranged on the side thereof.

[0042] The first discharge port 76, the second discharge port 86 and the booster 10 are respectively connected by the three-way valve 9. The three-way valve 9 mixes different curing agents. At the same time, the boosting force generated by the booster 10 is used to mix the curing agents of the first discharge port 76 and the second discharge port 86 and then transport them to the stirring equipment for spraying, thereby realizing automatic feeding.

[0043] In particular, in order to control the rate of output of the solidified material, a variable frequency air compressor 1 is formed by a variable frequency air compressor and a compressor, which can control the pressure, thereby preventing waste of materials and air dust pollution. The first annular air inlet 75 and the second annular air inlet 85 are used to loosen the solidified material in the tank to prevent the solidified material in the tank from accumulating and blocking the air inlet pipe. The feeding room is provided with a quantitative feeding device digital touch screen, which displays the curing agent control area and the recording area, and can control the pressure, delivery volume and the first air inlet valve 7 and the second air inlet valve 81 in the process of curing agent delivery in real time.

[0044] In addition, the quantitative feeding mechanism includes a first air inlet valve 71, a first discharge port 76, a second air inlet valve 81, a second discharge port 86 and a three-way valve 9. In order to control the discharge amount and discharge time, display and record the material amount of the setting area in real time, and control the automation of the first discharge port 76, the second discharge port 86 and the first air inlet valve 71, the second air inlet valve 81 and the air inlet valve switch of each discharge port in real time, ensure the amount of curing agent in each stirring interval, thereby ensuring the amount of curing agent in the entire block; remote operation can be realized, and the automation and intelligence of curing agent spraying can be realized, saving human resources and avoiding human-caused waste of resources; multiple first discharge ports 76 and second discharge ports 86 discharge ports spray at the same time to ensure the proportion of curing agent in the stirring process and realize quantitative and accurate feeding.

[0045] Example 3

[0046] like Figure 2 As shown, the embodiment of the present invention provides a shallow layer in-situ solidification construction method for ultra-thick sludge, comprising the following steps:

[0047] Construction technology for shallow in-situ solidification of ultra-thick silt layers: on-site pretreatment and preparation for in-situ solidification → determination of in-situ solidification mix ratio and construction technology test → in-situ solidification construction → in-situ solidification soil maintenance, testing and acceptance.

[0048] 1. On-site pretreatment and preparation for in-situ curing

[0049] (1) Pre-treat the water accumulation, surface vegetation, buried stones and garbage at the shallow in-situ solidification site of ultra-thick silt that may affect the quality of in-situ solidification, so that the in-situ solidification site meets the conditions for solidification construction.

[0050] (2) Construct temporary facilities such as temporary roads, water and electricity, offices and living quarters for in-situ curing construction, and on-site feeding background for in-situ curing to ensure that the water and electricity required for in-situ curing construction, roads for transporting the curing agent to the site, and the resources for curing personnel, offices and living quarters, as well as the conditions required for the construction of the curing device, are met.

[0051] (3) The in-situ curing device and feeding backstage are assembled and debugged on site to ensure the continuous in-situ curing and the curing quality.

[0052] (4) Delineate the on-site in-situ curing process test area, and lay out and divide the in-situ curing process test area.

[0053] 2. Calculate the proportion and modulation of the curing agent dosage according to the treatment thickness of the in-situ curing area, and use the curing agent automatic quantitative feeding system to set the curing agent content. Perform in-situ curing process experiments based on the set curing mix ratio. Determine a reasonable in-situ curing process based on the process experiments of the in-situ curing area, the total curing amount and the curing period requirements.

[0054] 3. In-situ curing construction

[0055] (1) The mixing equipment is directly inserted into the in-situ solidified soil for mixing;

[0056] (2) The in-situ curing stirring device slowly sinks, stirs and sprays the curing agent mixed slurry until the in-situ curing design depth is reached.

[0057] (3) The in-situ solidification stirring device is slowly lifted and stirred to ensure that the solidification slurry and the silt soil are fully mixed.

[0058] (4) Repeat steps (2) and (3) once and move to the next in-situ curing area.

[0059] 4. Maintenance, testing and acceptance of in-situ solidified soil

[0060] (1) The in-situ curing time of shallow silt shall not be less than 7 days.

[0061] (2) During the maintenance period, drainage measures should be taken in the in-situ solidification area. In rainy days or cold weather, the surface of the in-situ solidification site should be covered with a layer of plastic film or straw mat to reduce the impact of rain and cold weather on the maintenance strength of the solidified soil.

[0062] (3) After 28 days, the in-situ solidified soil shall be subjected to static penetration testing and the characteristic bearing capacity value shall not be less than 100 KPa.

[0063] Example 4

[0064] (1) Construction of temporary facilities such as temporary roads, water and electricity, office and living facilities, and on-site feeding facilities for in-situ curing construction, mainly including the laying of temporary water and electricity pipelines for construction to meet the water and electricity demand during in-situ curing; construction of temporary roads to meet the needs of vehicles supplying and transporting curing materials required for in-situ curing and the entry and exit of curing equipment; construction of temporary facilities for curing personnel’s office and living facilities to meet the office and living needs of curing management personnel and operating personnel. The construction of temporary facilities for on-site backstage feeding mainly involves the construction of temporary hardened sites required for the backstage feeding system to meet the installation of the backstage feeding device and to ensure the raw materials for the normal in-situ curing.

[0065] (2) The assembly and debugging of the in-situ curing device mainly provide guarantee for the formal in-situ curing, including the assembly and debugging of the background feeding system and the assembly and debugging of the in-situ curing device.

[0066] The working process of the backstage feeding is to first convey the curing agent in the (7) (8) storage tank to the silo of the operation backstage through a screw conveyor, and control the feeding and delivery of the materials through the backstage automatic quantitative feeding control system. Under the combined action of the air pressure provided by the (1) air compressor and the (10) booster, the curing agent in the backstage silo is mixed and then conveyed to the slurry delivery hose. The mixed curing agent is output through the spraying device of the strong material mixing head installed on the mixing device. Under the strong stirring of the mixing head, the output curing agent is evenly mixed with the soil to achieve the purpose of in-situ curing.

[0067] (3) The demarcation of the in-situ curing area is mainly achieved by dividing the in-situ curing process experimental section into areas in order to provide standard specifications for the confirmation of construction process experimental data and process determination.

[0068] For the process experiment area, 25m 2 ~30m 2 The area is divided into an area with a size of 5m×6m, and each area is divided into blocks of 1×1, that is, the in-situ curing test area is divided into several areas for curing test verification with different parameters.

[0069] Example 5

[0070] (1) Design the curing agent mix ratio based on the strength requirements of the cured soil.

[0071] (2) The curing agent is prepared according to the designed curing agent mix ratio parameters, and the on-site in-situ curing process test is carried out in blocks to verify the optimal curing agent mix ratio.

[0072] (3) Based on the implementation effect of the in-situ solidification test on the solidified soil, confirm the stirring and lifting speeds of the in-situ solidification device, the background feeding rate and the selection of the solidification device.

[0073] (4) Based on the total amount of in-situ curing and the curing period, determine the optimal curing construction process, the number of curing devices and personnel, and the total amount of curing materials required, so that technical personnel can prepare the required quantities of materials, equipment, and personnel in advance to ensure that the in-situ curing proceeds normally.

[0074] (5) Verify according to the selected curing device and process, check the condition, sharpness, firm installation and protection ring of the mixing head. Check the connection between the mixing device and the feeding system and whether the parameters of the feeding system are accurate to avoid leakage of curing slurry during construction. Before construction, the operator drives the mixing device to the in-situ curing site for trial mixing to check if there is any abnormality. If there is any abnormality, stop and correct it in time.

[0075] Example 6

[0076] (1) The in-situ solidification stirring device must be inserted vertically into the silt layer to stir the in-situ soil to ensure that the silty soil is not left out within the solidification range;

[0077] (2) The in-situ solidification stirring device is lowered to stir and spray the slurry to the solidification design elevation, and stays for 15 seconds to ensure that the sludge solidifying agent and the sludge layer are fully mixed;

[0078] (3) The lifting or lowering rate of the stirring device is controlled at 10-20s / m, and the injection rate of the curing agent mixed slurry is controlled at 100-250Kg / min to ensure that the stirring device is uniformly sprayed and stirred during the stirring of the silty soil layer and the injection of the curing slurry.

[0079] (4) In-situ curing treatment is carried out in the form of curing and advancing at the same time. During construction, detailed control is carried out according to the 5m×6m area, and the mixing process should ensure uniform spraying and mixing. After the mixing quantity construction in each area is completed, the next curing area is constructed. The overlap width between adjacent blocks should be no less than 8cm~12cm to avoid curing omissions, and finally solidify to form an overall uniform hard shell layer. The specific steps of in-situ curing of each block are: single point setting → small block mixing → preliminary leveling and pre-pressing.

[0080] (5) If there is a hard soil layer on the surface of extremely thick silt, an excavator should be used to pre-loosen the soil to ensure the solidification construction of the solidification device; the number of times of mixing and curing agent injection for each block should not be less than 2 times; the in-situ solidification process should be located and recorded in real time to ensure full coverage of the solidification and avoid omissions.

[0081] In-situ solidification treatment testing mainly tests the strength, thickness and bearing capacity of solidified soil. The main testing methods include light dynamic penetration test, static penetration test (mainly testing solidification strength), in-situ cross-plate shear test (mainly testing the shear strength of the foundation), load plate test (mainly bearing capacity), and core sampling (solidification thickness). The testing frequency should meet the design requirements.

[0082] The method of the present invention generates a pressure chamber through an air compressor and an air collecting device, distributes the pressure to the first storage tank and the second storage tank respectively, delivers the tank materials to the three-way valve respectively, and uses the booster thrust in the three-way valve to deliver the mixed curing agent to the curing treatment site. The actual curing effect on site is guaranteed, the curing cost is reduced, and the construction speed is accelerated. The method of the present invention, by increasing the detailed control of the on-site curing division area, adopts a curing and advancing method to avoid curing omissions, and is suitable for the in-situ curing construction of ultra-thick silt and shallow silt under large areas, large volumes, various conditions and ranges, and the curing coverage is guaranteed.

[0083] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A shallow in-situ solidification construction method for ultra-thick sludge, suitable for high water level and low bearing capacity sludge environment, characterized in that: The following steps are involved: S100: On-site pretreatment: Clean the solidification area, remove stagnant water, vegetation, rocks and garbage, take additional drainage measures to lower the water level in areas with high water levels and extra-thick silt, and build temporary construction roads, water and electricity facilities, and living and office facilities to ensure smooth access to the site and construction conditions for solidification equipment, materials and personnel; S200: Determine the curing agent ratio: According to the treatment depth of the curing area, the water content and compression coefficient of the sludge, the curing agent ratio is set through the curing agent automatic quantitative feeding system, and a small-scale in-situ curing process test is carried out. The injection amount and ratio of the curing agent are dynamically adjusted according to the test results to ensure that the curing agent and the sludge are evenly mixed to meet the strength requirements; S300: In-situ curing construction: Use deep insertion mixing equipment to vertically insert into the silt layer to stir and sink and spray the curing agent; after the mixing equipment sinks to the designed depth, it will stop briefly and stir and spray the curing agent, then stir and lift, and repeat the above actions once; continue stirring and spraying when the equipment is lifted to ensure that the curing agent and silt are fully mixed. After the regional curing is completed, an overlap area of ​​not less than 12 cm is formed in the adjacent curing areas to avoid curing omissions, so as to ensure the continuity after curing, and finally solidify to form an overall uniform hard shell layer; S400: Maintenance and testing: After in-situ solidification, maintenance shall be carried out for no less than 7 days. During this period, measures such as zoned drainage system and covering protective film shall be adopted to prevent the influence of rain and cold weather on the solidification effect; after 28 days, the solidification area shall be tested for strength to ensure that the bearing capacity of the solidified soil is not less than 100KPa.

2. The method for in-situ solidification of shallow ultra-thick sludge according to claim 1, characterized in that: The automatic quantitative feeding system for the curing agent in S200 dynamically adjusts the injection amount and stirring frequency of the curing agent according to the depth, water content and compression coefficient of the sludge to achieve uniform mixing of the curing agent and the sludge.

3. A shallow layer in-situ solidification construction method for ultra-thick sludge according to claim 1 or 2, characterized in that: The stirring device stirs and sinks and sprays the curing agent, and after stirring and sinking to the designed depth, it stays for a short time, and then stirs and rises to ensure that the curing agent is evenly distributed and to form a stirring overlap area of ​​not less than 12 cm in adjacent areas to avoid curing omissions.

4. An automatic quantitative feeding system, characterized in that: It includes a feeding mechanism for providing air pressure and curing material and a quantitative feeding mechanism for accurately controlling the delivery and mixing of the curing agent; wherein, The feeding mechanism comprises an air compressor (1), an air collecting device (2), a first air filter (3), a second air filter (5), a third air filter (6), a pressure chamber (4), a first storage tank (7), and a second storage tank (8), wherein the air compressor (1) and the air collecting device (2) are connected via a pipeline to generate compressed air and transport the compressed air to the pressure chamber (4), the pressure chamber (4) is connected to the first storage tank (7) via the second air filter (5), and is connected to the second storage tank (8) via the third air filter (6), the first storage tank (7) and the second storage tank (8) are connected via a three-way valve (9) for mixing the curing agent in the storage tanks, and a booster (10) is provided between the pressure chamber (4) and the three-way valve (9); The quantitative feeding mechanism comprises a first air inlet valve (71), a second air inlet valve (81), a first feed port (73), a second feed port (83), a first rotary paddle level controller (74), and a second rotary paddle level controller (84) for controlling the precise supply of the curing agent, and is used to adjust the amount of each supply and the spraying time to ensure that the curing agent is accurately mixed according to a preset ratio, and is driven by compressed air generated by an air compressor (1) and an air collecting device (2), and under the action of a booster (10), the mixed curing agent is transported to the stirring device through a three-way valve (9) for spraying.

5. The automatic quantitative feeding system according to claim 4, characterized in that: The first storage tank (7) and the second storage tank (8) respectively comprise a pressure gauge, a discharge port and an annular air inlet, wherein the first pressure gauge (72) of the first storage tank (7) is arranged at the top of the first storage tank (7), the first feed port (73) is located at the top of the first storage tank (7), the first discharge port (76) is located at the bottom of the first storage tank (7), and the first rotary paddle level controller (74) and the first annular air inlet (75) are located at the side of the first storage tank (7).

6. The automatic quantitative feeding system according to claim 5, characterized in that: The second storage tank (8) has a similar structure, including a second pressure gauge (82) arranged on the top of the second storage tank (8), a second feed port (83) located at the top of the second storage tank (8), a second discharge port (86) located at the bottom of the second storage tank (8), and a second rotary level controller (84) and a second annular air inlet (85) located on the side of the second storage tank (8).

7. The automatic quantitative feeding system according to any one of claims 4 to 6, characterized in that: The air compressor (1) is of variable frequency type.

8. The automatic quantitative feeding system according to any one of claims 4 to 6, characterized in that: It is equipped with a digital touch screen, which displays and controls the delivery process of the curing agent, including pressure, delivery volume and the switch status of the air inlet valve.

9. The automatic quantitative feeding system according to any one of claims 4 to 6, characterized in that: The quantitative feeding mechanism comprises a first air inlet valve (71), a first feed port (73), and a first rotary resistance material level controller (74).

10. The automatic quantitative feeding system according to any one of claims 4 to 6, characterized in that: The quantitative feeding mechanism comprises a second air inlet valve (81), a second feed port (83) and a second rotary resistance material level controller (84).

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