Ultrahigh-performance thixotropic slurry and application thereof
By optimizing the composition and injection method of thixotropic mud, ultra-high performance thixotropic mud was prepared, which solved the problems of drag reduction and posture control in the construction of ultra-large cross-section rectangular jacking pipes, and achieved high efficiency and safety in construction.
Patent Information
- Application Number
- CN202510763471.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-09
- Publication Date
- 2025-09-19
AI Technical Summary
The existing thixotropic mud has insufficient drag reduction effect in the construction of ultra-large cross-section rectangular jacking pipes, and its stability and posture control cannot meet the construction requirements, affecting the construction progress and safety.
By optimizing the composition of thixotropic mud, introducing nano-silica, modified bentonite, water reducer and thickener, ultra-high performance thixotropic mud is prepared. It is then injected into the gap between the jacking head and the soil at a specific pressure and volume using a high-pressure pump, and used in combination to reduce resistance and improve attitude control accuracy.
Significantly reduce jacking resistance by 30%-50%, improve the jacking machine head posture control accuracy to within 10mm, and ensure the smooth progress and safety of construction.
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of thixotropic mud, in particular to ultra-high performance thixotropic mud and application thereof. Background Art
[0002] In recent years, with the continuous advancement of urbanization, the development and utilization of underground space has received increasing attention. As an advanced underground engineering construction technology, super-large cross-section rectangular pipe jacking has been widely used in subway, integrated pipeline corridor and other projects due to its advantages such as small impact on the surrounding environment and high construction efficiency. However, during the construction of super-large cross-section rectangular pipe jacking, the friction resistance between the pipe jacking head and the surrounding soil is large, and problems such as offset and difficulty in posture control are prone to occur during the jacking process, which seriously affects the construction progress and project quality. How to effectively reduce the jacking resistance and improve the accuracy and stability of the posture control of the pipe jacking head has become a key issue that needs to be urgently solved in the construction of super-large cross-section rectangular pipe jacking, and has increasingly received high attention and continuous attention from construction units, design units and experts in related fields.
[0003] It cannot be ignored that the successful application of super-large cross-section rectangular pipe jacking construction depends to a large extent on breakthroughs in the pipe jacking machine head drag reduction technology. At present, the commonly used drag reduction technologies mainly include injecting lubricating slurry and using thixotropic mud. Although the thixotropic mud currently available on the market has a certain drag reduction effect, its performance indicators are difficult to meet the requirements of super-large cross-section rectangular pipe jacking construction, especially in the high-performance, long-distance jacking process. The stability, thixotropy and drag reduction effect of the thixotropic mud are all insufficient, resulting in the jacking resistance still being large, and it is difficult to effectively control the posture of the pipe jacking machine head, affecting the accuracy and safety of the pipe jacking construction. Therefore, it is urgent to develop an ultra-high performance thixotropic mud and find an effective application method for it in super-large cross-section rectangular pipe jacking construction. Summary of the Invention
[0004] In response to the above-mentioned prior art, the present invention optimizes the composition and ratio of thixotropic mud and introduces novel thixotropic materials and additives to produce an ultra-high-performance thixotropic mud with excellent thixotropy, stability, and drag-reducing effects. Furthermore, the present invention also investigates the specific application of this ultra-high-performance thixotropic mud in the construction of ultra-large cross-section rectangular pipe jacking, including the slurry injection method, injection pressure, injection volume, and its coordination with the pipe jacking head. These methods aim to effectively reduce jacking resistance, improve the accuracy and stability of the pipe jacking head's posture control, and ensure the smooth progress of ultra-large cross-section rectangular pipe jacking.
[0005] On the one hand, the present invention provides an ultra-high performance thixotropic mud, which includes the following components, calculated by weight: 1-5 parts of nano-silicon dioxide, 2-10 parts of modified bentonite, 85-95 parts of water, 0.1-0.5 parts of water reducer, and 0.2-1 parts of thickener.
[0006] Preferably, the nano-silicon dioxide has a particle size of 10-100 nm, a specific surface area of 100-300 m² / g, and a SiO2 content greater than 99.5%.
[0007] Preferably, the nano-scale silicon dioxide is fumed silica with a particle size of 20-50 nm, a specific surface area of 150-250 m² / g, and a SiO2 content greater than 99.8%.
[0008] Preferably, the expansion capacity of the modified bentonite is greater than 10 mL / g, and the content of montmorillonite is greater than 70%.
[0009] Preferably, the modified bentonite is sodium bentonite, which has been subjected to organic modification treatment, has a swelling capacity greater than 12 mL / g, and a montmorillonite content greater than 75%.
[0010] Preferably, the water reducer is a polycarboxylic acid-based high-performance water reducer with a water reduction rate greater than 25% and a solid content of 15-30%.
[0011] Preferably, the thickener is a nonionic cellulose ether with a viscosity ranging from 5000 to 40000 mPa·s and a degree of substitution of 0.8 to 1.5.
[0012] Preferably, the viscosity of the thickener is in the range of 10,000-20,000 mPa·s, and the degree of substitution is 1.0-1.2.
[0013] Preferably, the preparation method comprises the following steps: dry-mixing nano-silica and modified bentonite according to the weight parts for 1 minute, slowly adding water, continuing to stir for 3 minutes, then adding a water reducer and a thickener, and continuing to stir for 5 minutes until the mud is uniform and free of lumps.
[0014] On the other hand, the present invention also provides the application of the ultra-high performance thixotropic mud in ultra-large cross-section rectangular jacking pipes. The ultra-high performance thixotropic mud is injected into the gap between the jacking head and the surrounding soil at a pressure of 0.2-0.5 MPa by a high-pressure pump. The injection amount is 0.1-0.3 cubic meters per meter of the outer circumference of the jacking head, and the mud pressure is kept stable at 0.1-0.3 MPa during the jacking process.
[0015] In the present invention, the cross-sectional area of the super-large cross-section rectangular jacking pipe is greater than 25 square meters.
[0016] Compared to existing technologies, the present invention offers the following benefits: The ultra-high-performance thixotropic slurry provided by the present invention significantly improves its thixotropy, stability, and drag-reducing properties by optimizing its composition and properties, while ensuring the feasibility and cost-effectiveness of construction. Furthermore, the aforementioned application method significantly reduces jacking resistance by 30%-50% and improves the accuracy of the jacking head's posture control to within 10mm, thereby ensuring smooth construction of extremely large rectangular pipe jacking sections. DETAILED DESCRIPTION
[0017] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments.
[0018] Example 1: An ultra-high performance thixotropic slurry comprises the following components in parts by weight: 2 parts of nano-silicon dioxide, 6 parts of modified bentonite, 90 parts of water, 0.3 parts of a water reducer, and 0.6 parts of a thickener.
[0019] The nano-silica is fumed silica with a particle size of 20-50 nm, a specific surface area of 150-250 m² / g, and a SiO₂ content greater than 99.8%. The modified bentonite is sodium bentonite, organically modified to have a swelling capacity greater than 12 mL / g and a montmorillonite content greater than 75%. The water reducer is a high-performance polycarboxylic acid-based water reducer with a water reduction rate greater than 30% and a solids content of 20%. The thickener is a non-ionic cellulose ether with a viscosity range of 10,000-20,000 mPa·s and a degree of substitution of 1.0-1.2. Tap water is used.
[0020] Furthermore, the preparation method includes the following steps: dry mixing nano-silica and modified bentonite according to the weight parts for 1 minute, slowly adding water, continuing to stir for 3 minutes, then adding a water reducer and a thickener, and continuing to stir for 5 minutes until the mud is uniform and free of lumps.
[0021] Furthermore, when the ultra-high performance thixotropic mud is used in ultra-large cross-section rectangular jacking pipes, it is injected into the gap between the jacking head and the surrounding soil at a pressure of 0.2-0.5 MPa through a high-pressure pump, and the injection volume is 0.1-0.3 cubic meters per meter of the outer circumference of the jacking head, and the mud pressure is kept stable at 0.1-0.3 MPa during the jacking process.
[0022] Example 2: An ultra-high performance thixotropic slurry comprises the following components, calculated by weight: 1 part of nano-silicon dioxide, 10 parts of modified bentonite, 85 parts of water, 0.5 parts of a water reducer, and 0.2 parts of a thickener.
[0023] The nano-silica has a particle size of 10-100 nm, a specific surface area of 100-300 m² / g, and a SiO2 content greater than 99.5%. The modified bentonite has an expansion capacity greater than 10 mL / g and a montmorillonite content greater than 70%. The water reducer is a high-performance polycarboxylic acid-based water reducer with a water reduction rate greater than 25% and a solids content of 15%. The thickener is a non-ionic cellulose ether with a viscosity range of 5,000-40,000 mmPa·s and a degree of substitution of 0.8-1.5. Tap water is used.
[0024] Furthermore, the preparation method includes the following steps: dry mixing nano-silica and modified bentonite according to the weight parts for 1 minute, slowly adding water, continuing to stir for 3 minutes, then adding a water reducer and a thickener, and continuing to stir for 5 minutes until the mud is uniform and free of lumps.
[0025] Furthermore, the ultra-high performance thixotropic mud is applied to the super-large cross-section rectangular jacking pipe. It is injected into the gap between the jacking head and the surrounding soil at a pressure of 0.2-0.5 MPa by a high-pressure pump. The injection volume is 0.1-0.3 cubic meters per meter of the outer perimeter of the jacking head. The mud pressure is kept stable at 0.1-0.3 MPa during the jacking process. Example 3: An ultra-high performance thixotropic slurry comprises the following components in parts by weight: 5 parts of nano-silicon dioxide, 2 parts of modified bentonite, 95 parts of water, 0.1 parts of a water reducer, and 1 part of a thickener.
[0026] The nano-silica is fumed silica with a particle size of 20-50 nm, a specific surface area of 150-250 m² / g, and a SiO₂ content greater than 99.8%. The modified bentonite is sodium bentonite, organically modified to have a swelling capacity greater than 12 mL / g and a montmorillonite content greater than 75%. The water reducer is a high-performance polycarboxylic acid-based water reducer with a water reduction rate greater than 30% and a solids content of 30%. The thickener is a non-ionic cellulose ether with a viscosity range of 10,000-20,000 mPa·s and a degree of substitution of 1.0-1.2. Tap water is used.
[0027] Furthermore, the preparation method includes the following steps: dry mixing nano-silica and modified bentonite according to the weight parts for 1 minute, slowly adding water, continuing to stir for 3 minutes, then adding a water reducer and a thickener, and continuing to stir for 5 minutes until the mud is uniform and free of lumps.
[0028] Furthermore, when the ultra-high performance thixotropic mud is used in ultra-large cross-section rectangular jacking pipes, it is injected into the gap between the jacking head and the surrounding soil at a pressure of 0.2-0.5 MPa through a high-pressure pump, and the injection volume is 0.1-0.3 cubic meters per meter of the outer circumference of the jacking head, and the mud pressure is kept stable at 0.1-0.3 MPa during the jacking process.
[0029] The above are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent solutions made using the contents of the present invention specification, directly or indirectly applied in other related technical fields, are also within the patent protection scope of the present invention.
Claims
1. An ultra-high performance thixotropic slurry, characterized in that: The invention comprises the following components in parts by weight: 1-5 parts of nano-silicon dioxide, 2-10 parts of modified bentonite, 85-95 parts of water, 0.1-0.5 parts of water reducing agent and 0.2-1 parts of thickener.
2. The ultra-high performance thixotropic slurry according to claim 1, characterized in that: The nano-scale silicon dioxide has a particle size of 10-100 nm, a specific surface area of 100-300 m² / g, and a SiO2 content greater than 99.5%.
3. The ultra-high performance thixotropic slurry according to claim 2, characterized in that: The nano-scale silicon dioxide is fumed white carbon black with a particle size of 20-50 nm, a specific surface area of 150-250 m² / g, and a SiO2 content greater than 99.8%.
4. The ultra-high performance thixotropic slurry according to claim 1 or 2, characterized in that: The expansion capacity of the modified bentonite is greater than 10 mL / g, and the content of montmorillonite is greater than 70%.
5. The ultra-high performance thixotropic slurry according to claim 4, characterized in that: The modified bentonite is sodium bentonite that has been subjected to organic modification treatment, has a swelling capacity greater than 12 mL / g, and a montmorillonite content greater than 75%.
6. The ultra-high performance thixotropic slurry according to claim 1 or 2, characterized in that: The water reducer is a polycarboxylic acid-based high-performance water reducer with a water reduction rate greater than 25% and a solid content of 15-30%.
7. The ultra-high performance thixotropic slurry according to claim 1 or 2, characterized in that: The thickener is non-ionic cellulose ether with a viscosity range of 5000-40000 mPa·s and a degree of substitution of 0.8-1.
5.
8. The ultra-high performance thixotropic slurry according to claim 7, characterized in that: The viscosity of the thickener is in the range of 10,000-20,000 mPa·s, and the degree of substitution is in the range of 1.0-1.
2.
9. The ultra-high performance thixotropic slurry according to claim 1 or 2, characterized in that: The preparation method comprises the following steps: dry-mixing nano-silica and modified bentonite according to the weight parts for 1 minute, slowly adding water, continuing stirring for 3 minutes, then adding a water reducer and a thickener, and continuing stirring for 5 minutes until the mud is uniform and free of lumps.
10. Application of the ultra-high performance thixotropic slurry according to any one of claims 1 to 9 in super-large cross-section rectangular jacking pipes, characterized in that: The ultra-high performance thixotropic mud is injected into the gap between the jacking head and the surrounding soil at a pressure of 0.2-0.5 MPa through a high-pressure pump, with an injection volume of 0.1-0.3 cubic meters per meter of the outer circumference of the jacking head, and the mud pressure is kept stable at 0.1-0.3 MPa during the jacking process.