WO2022257305A1 - 一种基坑微生物土重力式围护结构及其施工方法 - Google Patents

一种基坑微生物土重力式围护结构及其施工方法 Download PDF

Info

Publication number
WO2022257305A1
WO2022257305A1 PCT/CN2021/122119 CN2021122119W WO2022257305A1 WO 2022257305 A1 WO2022257305 A1 WO 2022257305A1 CN 2021122119 W CN2021122119 W CN 2021122119W WO 2022257305 A1 WO2022257305 A1 WO 2022257305A1
Authority
WO
WIPO (PCT)
Prior art keywords
solution
pile
microbial soil
enclosure structure
cementing
Prior art date
Application number
PCT/CN2021/122119
Other languages
English (en)
French (fr)
Inventor
胡俊
张洪硕
熊明
占健健
王志鑫
曾晖
佳琳
Original Assignee
海南大学
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 海南大学 filed Critical 海南大学
Publication of WO2022257305A1 publication Critical patent/WO2022257305A1/zh

Links

Images

Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D17/00—Excavations; Bordering of excavations; Making embankments
    • E02D17/02—Foundation pits
    • E02D17/04—Bordering surfacing or stiffening the sides of foundation pits
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N1/00—Microorganisms, e.g. protozoa; Compositions thereof; Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor
    • C12N1/20—Bacteria; Culture media therefor
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D19/00—Keeping dry foundation sites or other areas in the ground
    • E02D19/06—Restraining of underground water
    • E02D19/12—Restraining of underground water by damming or interrupting the passage of underground water
    • E02D19/18—Restraining of underground water by damming or interrupting the passage of underground water by making use of sealing aprons, e.g. diaphragms made from bituminous or clay material
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
    • E02D5/22—Piles
    • E02D5/34—Concrete or concrete-like piles cast in position ; Apparatus for making same
    • E02D5/46—Concrete or concrete-like piles cast in position ; Apparatus for making same making in situ by forcing bonding agents into gravel fillings or the soil
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/30—Landfill technologies aiming to mitigate methane emissions

Definitions

  • the invention relates to the technical field of building foundation pit support engineering, in particular to a microbial soil gravity type enclosure structure for foundation pits and a construction method thereof.
  • foundation pit enclosure structure is the primary work of foundation pit support design, which should be comprehensively determined according to geological conditions, requirements of surrounding environment, characteristics and cost of different support forms, etc.
  • the commonly used forms of row piles or underground diaphragm walls mainly include bored piles + cement-soil mixing piles for water stop, reinforced concrete underground diaphragm walls, steel sheet piles, SMW piles, etc.
  • the material of bored piles + cement-soil mixing piles for water stop and reinforced concrete underground diaphragm wall is mainly reinforced concrete, which consumes a lot of materials and energy and is expensive; the overlapping position between steel sheet piles cannot meet the strict water-proof requirements.
  • the cement-soil gravity enclosure structure uses cement-based materials as the curing agent, and the cement-based materials and foundation soil are forcibly stirred by spraying construction through a mixing machine to form a continuously lapped cement-soil columnar reinforced solid retaining wall.
  • cement-based materials as the curing agent
  • foundation soil are forcibly stirred by spraying construction through a mixing machine to form a continuously lapped cement-soil columnar reinforced solid retaining wall.
  • the construction technology of forced mixing of cement-based materials and undisturbed soil has been vigorously developed and improved in recent years, and the depth of reinforcement and the compactness and uniformity of mixing have been improved.
  • traditional cementitious materials such as cement can easily change the pH value of the soil, making the soil alkaline and forming a certain range of erosion environment, which will cause adverse effects on groundwater and surrounding vegetation.
  • Microbial-induced calcium carbonate precipitation is a biomineralization process that exists widely in nature. It has a simple mechanism, is fast and efficient, and has good environmental tolerance. It will be used in foundation pit enclosure structures to achieve energy consumption. A new type of microbial soil reinforcement technology that is small and less polluting. The enzymes produced by microorganisms through their life activities generate calcite through enzymatic action, and fill in the voids of soil particles to play a cementing role. It is a green and scientific reinforcement method.
  • the existing microbial soil reinforcement technology often uses a step-by-step method to separately inject the bacterial solution and the cementing solution into the soil, such as patent 201510900093.8, a microbial soil-fixing CFG pile composite foundation and its construction method, and patent 201610933803.1, a shield tunnel end
  • the soil solidification method is carried out in two steps, so that the bacteria liquid, the cement solution and the soil are mixed and solidified to obtain the microbial soil reinforcement enclosure structure; but the existing microbial soil Soil solidification is easily induced by microorganisms, the controllability of the cementation reaction rate is poor, and the uniformity of the solidified soil is low, especially the soil solidified on soft soil foundations has poor durability and low compressive and shear strength; therefore, it is urgent to find
  • the invention discloses a microbial soil gravity enclosure structure and a construction method for improving the uniformity and durability of solidified soil and improving the performance of the microbial soil gravity enclosure structure.
  • the present invention proposes a microbial soil gravity enclosure structure and a construction method thereof, which can effectively improve the microbial-induced cementation reaction rate and improve the uniformity and durability of the solidified soil.
  • the invention provides a microbial soil gravity enclosure structure for a foundation pit.
  • the microbial soil gravity enclosure structure is composed of a stirring pile machine or a high-pressure jet grouting machine using a composite bacterial solution, a cementing solution and a solid-carrying material to stir with the soil. solidified to form a continuous lapped microbial soil columnar reinforced solid retaining wall; the solid-loaded material is mixed with straw fiber powder and expanded perlite powder with a mass ratio of (5-8):(1-3); the
  • the cementing solution is a cementing solution containing 0.05-0.1 mol/L sodium phosphate buffer solution, and the pH value of the sodium phosphate buffer solution is 5.5-6.8.
  • the cementing solution includes a calcium chloride solution with a concentration of 0.6-1.5 mol/L, a urea solution with a concentration of 0.6-1.5 mol/L, and a sodium phosphate buffer solution with a pH of 5.5-6.8 and 0.05-0.1 mol/L.
  • the straw fiber powder is crushed from corn or wheat straw, adding a sodium hydroxide solution with a mass concentration of 0.5-1% according to a material-to-liquid ratio of 40-60ml/g, adding 5-8mg/L glycerin and stirring for 30- After 60 minutes, the loose straw fiber powder is obtained after being washed with an aqueous solution of acetic acid with a mass concentration of 0.5-1%, and dried.
  • the mass ratio of the composite bacteria solution, cement solution and solid-carrying material is 1:1:(8-10).
  • the microbial soil gravity type enclosure structure is provided with reinforcing materials inside, and the reinforcing materials are moso bamboo or wooden piles.
  • a kind of construction method of above-mentioned microbial soil gravity type enclosure structure of foundation pit comprises the following steps:
  • Step 1 Pile driver positioning, the pile position is determined by a stirring pile driver or a high-pressure jet grouting machine;
  • Step 2 Stir the composite bacterial solution to sink: Pour the pile driver or high-pressure jet grouting machine into the bacterial solution and solid-carrying materials, and pre-mix the composite bacterial solution and solid-carrying materials during the rotation and sinking process. When the grouting port sinks To the design depth, spray the compound bacterial liquid mixture on the spot for 60-70 seconds;
  • Step 3 Stir the composite bacteria spray liquid to rise: the stirring pile driver or the high-pressure jet grouting machine rises at a constant speed while stirring, and keep spraying the composite bacteria liquid mixture, and stop rising when the spray port rises to the top of the designed pile;
  • Step 4 Stirring and spraying cementing solution sinking: Pour the cementing solution into the stirring pile machine or high-pressure jet grouting machine, stir the cementing solution during the rotation and sinking process, when the spraying port sinks to the design depth, spray the cementing solution on the spot for 60 ⁇ 70s;
  • Step 5 Stir and spray the cementing solution to rise: Stir the pile driver or high-pressure jet grouting machine to rise at a constant speed while stirring, and keep spraying the cementing solution. When the spray port rises to the designed pile top, stop rising and stir for 4 to 6 seconds;
  • Step 6 Complete the construction of a single microbial soil mixing pile, move the mixing pile machine or high-pressure jet grouting machine to the next pile position, repeat steps 1 to 5, and form a foundation composed of multiple microbial soil mixing piles. Pit microbial soil gravity enclosure structure.
  • step 6 after the construction of each microbial soil mixing pile is completed, the reinforcement material is immediately constructed, and the reinforcement material is pressed into the center of the microbial soil mixing pile.
  • the depth is 1-2m shorter than the microbial soil mixing pile; the diameter of the reinforcement material is set according to the diameter of the microbial soil mixing pile, and the diameter is controlled between 50mm and 100mm.
  • straight moso bamboo or wooden piles are inserted into the microbial soil mixing pile as reinforcement materials. reinforcement effect.
  • the loose and broken part of the top of the pile head is excavated to expose the top of the 20cm ⁇ 30cm reinforced material, and the reinforced material head is connected with a steel mesh along the top of the pile, and the township plate is formed by pouring C20 concrete , The thickness of the township board is 20mm, and the reinforcement material enters the concrete township board at least 50mm.
  • step 4 repeating steps 2-3 is also included; before step 6, repeating steps 4-5 is also included.
  • the microbial soil gravity enclosure structure can be distinguished by plane layout, and can include any one of full-bore layout, grid-shaped layout and wide-narrow combination zigzag layout, and can be distinguished by vertical layout. Equal section arrangement or stepped arrangement.
  • the beneficial effect of the present invention is: the microbial soil gravity enclosure structure of the foundation pit of the present invention can obtain soil solidification by using composite bacterial liquid, cementing solution and solid-carrying materials to stir and solidify the soil. Uniform and durable microbial soil columnar reinforced solid retaining wall.
  • the cementing solution of L sodium phosphate buffer is beneficial to prolong the survival time of bacteria, maintain the activity of microorganisms, promote the formation of more calcium carbonate crystals with cementing properties by microorganisms, and make part of the composite bacterial liquid inside the straw fiber powder and the cementing solution.
  • the use of expanded perlite powder covered by partial microbial cementation can promote the mixing of compound bacteria solution, better evenly fill and diffuse in the gaps of soft soil particles, and improve the compactness of microbial soil solidification structure , improve the uniformity of the solidified soil, thereby greatly enhancing the durability of the microbial soil solidified structure, and the continuous lapped microbial soil gravity enclosure structure formed by it has good shear resistance, compression resistance and impermeability.
  • Fig. 1 is the structural side schematic diagram of microbial soil gravity type enclosure of foundation pit of the present invention
  • Fig. 2 is the plane layout diagram of the microbial soil gravity type enclosure of the foundation pit of the present invention
  • a microbial soil gravity enclosure structure for a foundation pit which is stirred by a stirring pile machine or a high-pressure jet grouting machine with a composite bacterial solution, a cementing solution, and a solid-carrying material to form a continuous overlapping microbial soil column reinforcement solid block Wall;
  • the solid-loaded material is mixed with straw fiber powder and expanded perlite powder with a mass ratio of 7:2;
  • the mass ratio of the composite bacteria solution, the cementing solution and the solid-carrying material is: 1:1:9.
  • a construction method for a foundation pit microbial soil gravity type enclosure structure comprising the following steps:
  • Step 1 Pile driver positioning, the pile position is determined by the stirring pile driver
  • Step 2 Stir the compound bacterial liquid to sink: the stirring pile driver pours the bacterial liquid and solid-carrying materials, and pre-mixes the compound bacterial liquid and solid-carrying materials during the rotation and sinking process.
  • the shotcrete port sinks to the design depth, it will Spray the compound bacterial liquid mixture for 60s;
  • the solid-carrying material is a mixture of wheat straw fiber powder and expanded perlite powder with a mass ratio of 5:1;
  • the composite bacterial solution and the solid-carrying material are mixed according to the mass ratio: 1:8;
  • Step 3 Stir the compound bacteria spray liquid to rise: the stirring pile machine rises at a constant speed while stirring, and keeps spraying the compound bacteria liquid mixture, and stops rising when the spray port rises to the design pile top;
  • Step 4 Stir and spray the cementing solution to sink: pour the cementing solution into the stirring pile machine, stir the cementing solution during the rotation and sinking process, when the spraying port sinks to the design depth, spray the cementing solution on the spot for 60-70s;
  • the mass ratio of composite bacteria solution, cement solution and solid-carrying material is: 1:1:8;
  • Step 5 Stir and spray the cementing solution to rise: the stirring pile machine rises at a constant speed while stirring, and keeps spraying the cementing solution. When the spraying port rises to the top of the designed pile, stop rising and stir for 4 seconds;
  • Step 6 Complete the construction of a single microbial soil mixing pile, move the mixing pile machine or high-pressure jet grouting machine to the next pile position, repeat steps 1 to 5, and form a foundation composed of multiple microbial soil mixing piles. Pit microbial soil gravity enclosure structure.
  • a construction method for a foundation pit microbial soil gravity type enclosure structure comprising the following steps:
  • Step 1 Pile driver positioning, the pile position is determined by the high-pressure jet grouting machine
  • Step 2 Stir the composite bacterial solution to sink: the high-pressure jet grouting machine pours the bacterial solution and solid-carrying materials, and pre-mixes the composite bacterial solution and solid-carrying materials during the rotation and sinking process. When the grouting port sinks to the design depth, Spray the compound bacterial liquid mixture on the spot for 70s;
  • the solid-carrying material is a mixture of wheat straw fiber powder and expanded perlite powder with a mass ratio of 8:3;
  • Composite bacteria solution and solid-carrying material are mixed according to the mass ratio: 1:10;
  • Step 3 Stir the compound bacteria spray liquid to rise: the high-pressure jet grouting machine rises at a constant speed while stirring, and keeps spraying the compound bacteria liquid mixture, and stops rising when the spray port rises to the top of the designed pile;
  • Step 4 Stir and spray the cementing solution to sink: pour the cementing solution into the high-pressure jet grouting machine, stir the cementing solution during the rotation and sinking process, and spray the cementing solution on the spot for 70 seconds when the spray port sinks to the designed depth;
  • the mass ratio of composite bacteria solution, cement solution and solid-carrying material is: 1:1:10;
  • Step 5 Stir and spray the cementing solution to rise: the high-pressure jet grouting machine rises at a constant speed while stirring, and keeps spraying the cementing solution. When the spraying port rises to the top of the designed pile, stop rising and stir for 6 seconds;
  • Step 6 Complete the construction of a single microbial soil mixing pile, move the mixing pile machine or high-pressure jet grouting machine to the next pile position, repeat steps 1 to 5, and form a foundation composed of multiple microbial soil mixing piles. Pit microbial soil gravity enclosure structure.
  • a construction method for a foundation pit microbial soil gravity type enclosure structure comprising the following steps:
  • Step 1 Pile driver positioning, the pile position is determined by the stirring pile driver
  • Step 2 Stir the compound bacterial liquid to sink: the stirring pile driver pours the bacterial liquid and solid-carrying materials, and pre-mixes the compound bacterial liquid and solid-carrying materials during the rotation and sinking process.
  • the shotcrete port sinks to the design depth, it will Spray the compound bacterial liquid mixture for 60s;
  • Each 1L of nutrient salt solution contains 6.5g soybean peptone, 17g tryptone, and 4g soybean meal peptone , 5.5g sodium chloride and 20g urea, the pH value of nutrient salt solution is 7.25;
  • the solid-carrying material is a mixture of straw fiber powder and expanded perlite powder with a mass ratio of 7:2; the straw fiber powder is crushed from wheat straw and added with a mass concentration of 1% hydrogen at a material-to-liquid ratio of 40ml/g Sodium oxide solution, adding 8 mg/L glycerin, mixing and stirring for 30 minutes, washing with 0.5% acetic acid aqueous solution and drying to obtain loose straw fiber powder;
  • the composite bacteria solution and the solid-carrying material are mixed in a mass ratio of 1:9;
  • Step 3 Stir the compound bacteria spray liquid to rise: the stirring pile machine rises at a constant speed while stirring, and keeps spraying the compound bacteria liquid mixture, and stops rising when the spray port rises to the design pile top;
  • Step 4 Stir and spray the cementing solution to sink: pour the cementing solution into the stirring pile machine, stir the cementing solution during the rotation and sinking process, and spray the cementing solution on the spot for 60 seconds when the spraying port sinks to the designed depth;
  • the mass ratio of composite bacteria solution, cement solution and solid-carrying material is: 1:1:9;
  • Step 5 Stir and spray the cementing solution to rise: the stirring pile machine rises at a constant speed while stirring, and keeps spraying the cementing solution. When the spraying port rises to the top of the designed pile, stop rising and stir for 5s;
  • Step 6 After the construction of each microbial soil mixing pile is completed, the reinforcement material is immediately constructed, and the moso bamboo reinforcement material is pressed into the center of the microbial soil mixing pile.
  • the thick section of the moso bamboo reinforcement material faces upward, and the thin section faces downward.
  • the depth of the microbial soil mixing pile is 1m short; the diameter of the reinforced material is 50mm.
  • a construction method for a foundation pit microbial soil gravity type enclosure structure comprising the following steps:
  • Step 1 Pile driver positioning, the pile position is determined by the high-pressure jet grouting machine
  • Step 2 Stir the composite bacterial solution to sink: the high-pressure jet grouting machine pours the bacterial solution and solid-carrying materials, and pre-mixes the composite bacterial solution and solid-carrying materials during the rotation and sinking process. When the grouting port sinks to the design depth, Spray the compound bacterial liquid mixture on the spot for 60s;
  • Each 1L of nutrient salt solution contains 6.5g soybean peptone, 17g tryptone, and 4g soybean meal peptone , 5.5g sodium chloride and 20g urea, the pH value of nutrient salt solution is 7.25;
  • the solid-loaded material is a mixture of straw fiber powder and expanded perlite powder with a mass ratio of 6:2; the straw fiber powder is crushed from corn stalks and added with a mass concentration of 0.5% sodium hydroxide at a material-to-liquid ratio of 60ml/g solution, adding 5 mg/L glycerin, mixing and stirring for 60 min, washing with 1% acetic acid aqueous solution, and drying to obtain loose straw fiber powder;
  • the composite bacteria solution and the solid-carrying material are mixed in a mass ratio of 1:9;
  • Step 3 Stir the compound bacteria spray liquid to rise: the high-pressure jet grouting machine rises at a constant speed while stirring, and keeps spraying the compound bacteria liquid mixture, and stops rising when the spray port rises to the top of the designed pile;
  • Step 4 Stir and spray the cementing solution to sink: pour the cementing solution into the high-pressure jet grouting machine, stir the cementing solution during the rotation and sinking process, and spray the cementing solution on the spot for 60 seconds when the grouting port sinks to the designed depth;
  • the mass ratio of composite bacteria solution, cement solution and solid-carrying material is: 1:1:9;
  • Step 5 Stir and spray the cementing solution to rise: the high-pressure jet grouting machine rises at a constant speed while stirring, and keeps spraying the cementing solution. When the spraying port rises to the top of the designed pile, stop rising and stir for 5 seconds;
  • Step 6 After the construction of each microbial soil mixing pile is completed, the reinforcement material is immediately constructed, and the wooden pile reinforcement material is pressed into the center of the microbial soil mixing pile.
  • the thick section of the wooden pile reinforcement material faces upwards and the thin section faces downward.
  • the depth is 2m shorter than the depth of the microbial soil mixing pile; the diameter of the reinforced material is 100mm.
  • the loose and broken part of the top of the pile head is excavated to expose the top of the 30cm reinforced material, and the reinforced material head is covered with steel bars along the top of the pile. Connect the net, and pour C20 concrete to form a township plate.
  • the thickness of the township plate is 20mm, and the reinforcement material enters the concrete township plate for no less than 50mm.
  • Preparation of microbial soil samples take soft soil with a moisture content of 50-55%, use a certain amount of composite bacterial liquid, cementing solution and solid-carrying material raw materials, first mix and stir the composite bacterial liquid and cementing solution, and then The compound bacterial liquid mixture and cementing solution were added to the soft soil, stirred evenly, and cured in a constant humidity and incubator at a temperature of 25°C and a humidity of 98%.
  • Each solidified microbial soil block was a 10 ⁇ 10cm square sample.
  • the shear strength is measured by ZJ strain-controlled direct shear instrument, the shear rate is 0.8mm/min, the normal stress is 100kpa, and the shear stress is measured.
  • test group
  • the composite bacteria solution, cement solution and solid-carrying material raw materials used in the construction of the foundation pit microbial soil gravity type enclosure structure in Examples 2-4 were used to prepare the above-mentioned microbial soil blocks, as experimental groups 1-3;
  • Contrast group 1 The above-mentioned microbial soil block was prepared only with composite bacterial solution and cement solution; no immobilized material was added, and the rest were the same as experimental group 3;
  • Contrast group 2 the cementation solution without sodium phosphate buffer added to the cementation solution, and the rest are the same as the experimental group 3.
  • Comparative group 3 The mass ratio of straw fiber powder and expanded perlite powder in the solid-carrying material is 1:1, and the rest is the same as the experimental group 3.
  • Comparative group 4 A single straw fiber powder is used as the immobilized material, and the rest is the same as that of the experimental group 3.
  • the soft soil microbial soil blocks obtained by mixing and solidifying the soil with the compound bacterial solution, cementing solution and solid-carrying materials have high compressive strength, shear strength and anti-permeability, which can be used for the gravity of microbial soil in foundation pits.
  • the solid solidification of the type enclosure structure is uniform, and the durability is good.
  • the physical properties of the solidified microbial soil block of experimental group 3 were the best.

Landscapes

  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • General Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Paleontology (AREA)
  • Civil Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Biotechnology (AREA)
  • Hydrology & Water Resources (AREA)
  • Environmental & Geological Engineering (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Organic Chemistry (AREA)
  • Genetics & Genomics (AREA)
  • Zoology (AREA)
  • Microbiology (AREA)
  • Medicinal Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Virology (AREA)
  • Tropical Medicine & Parasitology (AREA)
  • Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)

Abstract

本发明提供一种基坑微生物土重力式围护结构及其施工方法，该微生物土重力式围护结构是由搅拌桩机或高压喷射注浆机采用复合菌液、胶结溶液和固载材料与土体搅拌，固化形成连续搭接的微生物土柱状加固体挡墙；所述固载材料是由质量比为（5～8）:（1～3）的秸秆纤维粉末和膨胀珍珠岩粉末混合而成；所述胶结溶液为含有0.05～0.1mol/L磷酸钠缓冲液的胶结溶液，磷酸钠缓冲液的pH值为5.5～6.8；本发明通过采用复合菌液、胶结溶液和固载材料与土体搅拌固化，可有效改善微生物诱导的胶结反应速率，提高固化土体均匀性和耐久性能。

Description

一种基坑微生物土重力式围护结构及其施工方法 技术领域
本发明涉及建筑基坑支护工程技术领域，特别涉及一种基坑微生物土重力式围护结构及其施工方法。
背景技术
基坑围护结构的合理选择，是基坑支护设计的首要工作，应根据地质条件，周边环境的要求及不同支护形式的特点、造价等综合确定。目前常用的排桩或地下连续墙形式主要有钻孔灌注桩+水泥土搅拌桩止水、钢筋混凝土地下连续墙、钢板桩、SMW工法桩等。其中，钻孔灌注桩+水泥土搅拌桩止水、钢筋混凝土地下连续墙的材料主要为钢筋混凝土，耗材、耗能多，造价高；钢板桩之间的搭接位置无法满足较严格的隔水要求，当基坑开挖较深时钢板桩往往漏水严重；SMW工法桩当基坑开挖较深时，水泥土桩受力开裂可能导致隔水失效，且水泥土不可回收，造价仍然较高。
水泥土重力式围护结构是以水泥系材料为固化剂，通过搅拌机械采用喷浆施工将水泥系材料和地基土强行搅拌，形成连续搭接的水泥土柱状加固体挡墙。目前水泥系材料和原状土强行搅拌的施工技术，近年来得到大力发展和改进，加固深度和搅拌密实性、均匀性均得到提高。但水泥等传统的胶凝材料易改变土体的pH值，使土体呈碱性并形成一定范围的侵蚀环境，对地下水与周围植被均会造成不良的影响。因此，研究节能减排、生态环保、经济高效的新型基坑重力式围护结构及其施工方法意义重大。如何寻找到具有能耗小、污染少且性能优良的新型基坑重力式围护结构技术是目前亟待坚决的关键问题。
微生物诱导碳酸钙沉淀(MICP)是一种在自然界中广泛存在的生物矿化过程，机理简单，快速高效，环境耐受性好，现有将用于基坑围护结构中，以实 现能耗小，污染小的新型的微生物土加固技术，微生物通过其生命活动产生的酶通过酶化作用生成方解石，填充在土体颗粒空隙中起胶结作用，是一种绿色科学的加固方法。现有的微生物土加固技术常采用分步法将菌液和胶结溶液分开依次注入土体中，如专利201510900093.8一种微生物固土CFG桩复合地基及施工方法和专利201610933803.1一种盾构隧道端头微生物加固结构及其施工方法中的微生物加固区施工，均分2步进行土体固化方法，以使菌液、胶结溶液与土体混合固化，得到微生物土加固围护结构；但现有的微生物土固化容易受微生物诱导的胶结反应速率的可控性差，固化土体均匀度较低，尤其是软土地基固化的土体的耐久性差，抗压抗剪强度低等不足；因此，亟需寻找一种基坑微生物土重力式围护结构及施工方法，以改善固化土体均匀性和耐久性等问题，提高微生物土重力式围护结构性能。
发明内容
鉴于此，本发明提出了一种基坑微生物土重力式围护结构及其施工方法，可有效改善微生物诱导的胶结反应速率，提高固化土体均匀性和耐久性能。
本发明的技术方案是这样实现的：
本发明提供一种基坑微生物土重力式围护结构，该微生物土重力式围护结构是由搅拌桩机或高压喷射注浆机采用复合菌液、胶结溶液和固载材料与土体搅拌，固化形成连续搭接的微生物土柱状加固体挡墙；所述固载材料是由质量比为(5～8):(1～3)的秸秆纤维粉末和膨胀珍珠岩粉末混合而成；所述胶结溶液为含有0.05～0.1mol/L磷酸钠缓冲液的胶结溶液，所述磷酸钠缓冲液的pH值为5.5～6.8。
进一步说明，所述复合菌液包括浓度OD600＝1.3～1.5的巴氏芽孢杆菌、浓度OD600＝0.6～0.8的科氏芽孢杆菌和营养盐溶液，每1L的营养盐溶液中含有 6～7g大豆蛋白胨、16～18g胰蛋白胨、3～5g豆粕蛋白胨、5～6g氯化钠和19～21g尿素，营养盐溶液的pH值为7.2～7.3。
进一步说明，所述胶结溶液包括浓度为0.6～1.5mol/L氯化钙溶液、0.6～1.5mol/L的尿素溶液和pH＝5.5～6.8，0.05～0.1mol/L磷酸钠缓冲液。
进一步说明，所述秸秆纤维粉末是由玉米或小麦秸秆粉碎后按料液比40～60ml/g加入质量浓度为0.5～1％的氢氧化钠溶液，加入5～8mg/L甘油混合搅拌30～60min，经质量浓度为0.5～1％的醋酸水溶液清洗，干燥后得到的疏松的秸秆纤维粉末。
进一步说明，所述复合菌液、胶结溶液和固载材料的质量比为1:1:(8～10)。
进一步说明，所述微生物土重力式围护结构内部设有加筋材料，所述加筋材料为毛竹或木桩。
一种上述的基坑微生物土重力式围护结构的施工方法，包括如下步骤：
步骤1：桩机定位，由搅拌桩机或高压喷射注浆机确定桩位；
步骤2：搅拌复合菌液下沉：搅拌桩机或高压喷射注浆机灌入菌液和固载材料，并在旋转下沉过程预搅拌复合菌液和固载材料，当喷浆口下沉至设计深度，原地喷复合菌液混合料60～70s；
步骤3：搅拌复合喷菌液上升：搅拌桩机或高压喷射注浆机边搅拌边匀速上升，并保持喷复合菌液混合料，当喷浆口上升至设计桩顶时停止上升；
步骤4：搅拌喷胶结溶液下沉：搅拌桩机或高压喷射注浆机灌入胶结溶液，在旋转下沉过程搅拌胶结溶液，当喷浆口下沉至设计深度，原地喷胶结溶液60～70s；
步骤5：搅拌喷胶结溶液上升：搅拌桩机或高压喷射注浆机边搅拌边匀速上升，并保持喷胶结溶液，当喷浆口上升至设计桩顶时停止上升，搅拌4～6s；
步骤6：完成单根微生物土搅拌桩施工，搅拌桩机或高压喷射注浆机移机至下一桩位，重复步骤1～5，形成由多个微生物土搅拌桩连续搭接而成的基坑微生物土重力式围护结构。
进一步说明，步骤6中，每根微生物土搅拌桩施工完成后，随即施工加筋材料，向微生物土搅拌桩桩中心压入加筋材料，加筋材料粗段朝上，细段朝下，插入深度比微生物土搅拌桩深度短1-2m；加筋材料直径根据微生物土搅拌桩直径设置，直径控制在50mm～100mm之间。为增加微生物土搅拌桩的整体连接和提高抗弯刚度，通过微生物土搅拌桩中插入通直毛竹或木桩作为加筋材料，加筋材料在搅拌桩机钻杆提出后立即插入，有利于提高加固效果。
进一步说明，加筋材料施工完成后，挖除桩头顶部松散破碎的部分，露出20cm～30cm加筋材料顶部，沿桩顶将加筋材料头用钢筋网连接，并用C20混凝土浇筑形成镇口板，镇口板板厚20mm，加筋材料进入混凝土镇口板不少于50mm。
更优选的，单根微生物土搅拌桩施工过程中，在步骤4前，还包括重复步骤2-3；在步骤6前，还包括重复步骤4-5。
更优选的，所述微生物土重力式围护结构，按平面布置区分，可包括满膛布置、格栅形布置和宽窄结合的锯齿形布置中的任意一种，按竖向布置区分，可包括等断面布置或台阶形布置。
与现有技术相比，本发明的有益效果是：本发明的基坑微生物土重力式围护结构，通过采用复合菌液、胶结溶液和固载材料与土体搅拌固化，可获得土体固化均匀、耐久性好的微生物土柱状加固体挡墙。其中，通过采用由秸秆纤维粉末和膨胀珍珠岩粉末混合而成的固载材料与复合菌液、胶结溶液组合，不仅可有效固载微生物，并结合添加pH＝5.5～6.8，0.05～0.1mol/L磷酸钠缓冲液的胶结溶液，有利于延长细菌的存活时间，维持微生物活性，促进微生物生成更多的具有胶结性能的碳酸钙晶体，而且使部分复合菌液于秸秆纤维粉末内部与 胶结溶液发生反应，有利于减缓胶结反应速率；同时，利用经部分微生物胶结包覆的膨胀珍珠岩粉末可促进复合菌液混合更好地均匀填充扩散于软土体颗粒空隙中，改善微生物土固化结构密实度，提高固化土体均匀性，进而大大增强了微生物土固化结构的耐久性能，其形成的连续搭接的微生物土重力式围护结构的抗剪、抗压和抗渗性好。
附图说明
图1为本发明基坑微生物土重力式围护的结构侧面示意图；
图2为本发明基坑微生物土重力式围护的平面布置图；
具体实施方式
为了更好理解本发明技术内容，下面提供具体实施例，对本发明做进一步的说明。
本发明实施例所用的实验方法如无特殊说明，均为常规方法。
本发明实施例所用的材料、试剂等，如无特殊说明，均可从商业途径得到。
实施例1
一种基坑微生物土重力式围护结构，由搅拌桩机或高压喷射注浆机采用复合菌液、胶结溶液和固载材料与土体搅拌，固化形成连续搭接的微生物土柱状加固体挡墙；所述固载材料是由质量比为7:2的秸秆纤维粉末和膨胀珍珠岩粉末混合而成；
所述胶结溶液包括浓度为1.0mol/L氯化钙溶液、1.0mol/L的尿素溶液和pH＝5.5，0.05mol/L磷酸钠缓冲液；
所述复合菌液包括浓度OD600＝1.5的巴氏芽孢杆菌、浓度OD600＝0.7的科氏芽孢杆菌和营养盐溶液，每1L的营养盐溶液中含有6.5g大豆蛋白胨、17g胰蛋白胨、4g豆粕蛋白胨、5.5g氯化钠和20g尿素，营养盐溶液的pH值为7.25；
所述复合菌液、胶结溶液和固载材料的质量比为：1:1:9。
实施例2
一种基坑微生物土重力式围护结构的施工方法，包括如下步骤：
步骤1：桩机定位，由搅拌桩机确定桩位；
步骤2：搅拌复合菌液下沉：搅拌桩机灌入菌液和固载材料，并在旋转下沉过程预搅拌复合菌液和固载材料，当喷浆口下沉至设计深度，原地喷复合菌液混合料60s；
其中，复合菌液包括浓度OD600＝1.3的巴氏芽孢杆菌、浓度OD600＝0.6的科氏芽孢杆菌和营养盐溶液，每1L的营养盐溶液中含有6g大豆蛋白胨、16g胰蛋白胨、3g豆粕蛋白胨、5g氯化钠和19g尿素，营养盐溶液的pH值为7.2；
固载材料是由质量比为5:1的小麦秸秆纤维粉末和膨胀珍珠岩粉末混合而成；
复合菌液和固载材料按质量比为：1:8混合；
步骤3：搅拌复合喷菌液上升：搅拌桩机边搅拌边匀速上升，并保持喷复合菌液混合料，当喷浆口上升至设计桩顶时停止上升；
步骤4：搅拌喷胶结溶液下沉：搅拌桩机灌入胶结溶液，在旋转下沉过程搅拌胶结溶液，当喷浆口下沉至设计深度，原地喷胶结溶液60～70s；
其中，胶结溶液包括浓度为0.6mol/L氯化钙溶液、0.6mol/L的尿素溶液和pH＝5.5，0.05mol/L磷酸钠缓冲液；
复合菌液、胶结溶液和固载材料的质量比为：1:1:8；
步骤5：搅拌喷胶结溶液上升：搅拌桩机边搅拌边匀速上升，并保持喷胶结溶液，当喷浆口上升至设计桩顶时停止上升，搅拌4s；
步骤6：完成单根微生物土搅拌桩施工，搅拌桩机或高压喷射注浆机移机至下一桩位，重复步骤1～5，形成由多个微生物土搅拌桩连续搭接而成的基坑微生物土重力式围护结构。
实施例3
一种基坑微生物土重力式围护结构的施工方法，包括如下步骤：
步骤1：桩机定位，由高压喷射注浆机确定桩位；
步骤2：搅拌复合菌液下沉：高压喷射注浆机灌入菌液和固载材料，并在旋转下沉过程预搅拌复合菌液和固载材料，当喷浆口下沉至设计深度，原地喷复合菌液混合料70s；
其中，复合菌液包括浓度OD600＝1.5的巴氏芽孢杆菌、浓度OD600＝0.8的科氏芽孢杆菌和营养盐溶液，每1L的营养盐溶液中含有7g大豆蛋白胨、18g胰蛋白胨、5g豆粕蛋白胨、6g氯化钠和21g尿素，营养盐溶液的pH值为7.3；
固载材料是由质量比为8:3的小麦秸秆纤维粉末和膨胀珍珠岩粉末混合而成；
复合菌液和固载材料按质量比为：1:10混合；
步骤3：搅拌复合喷菌液上升：高压喷射注浆机边搅拌边匀速上升，并保持喷复合菌液混合料，当喷浆口上升至设计桩顶时停止上升；
步骤4：搅拌喷胶结溶液下沉：高压喷射注浆机灌入胶结溶液，在旋转下沉过程搅拌胶结溶液，当喷浆口下沉至设计深度，原地喷胶结溶液70s；
其中，胶结溶液包括浓度为1.5mol/L氯化钙溶液、1.5mol/L的尿素溶液和pH＝6.8，0.1mol/L磷酸钠缓冲液；
复合菌液、胶结溶液和固载材料的质量比为：1:1:10；
步骤5：搅拌喷胶结溶液上升：高压喷射注浆机边搅拌边匀速上升，并保持喷胶结溶液，当喷浆口上升至设计桩顶时停止上升，搅拌6s；
步骤6：完成单根微生物土搅拌桩施工，搅拌桩机或高压喷射注浆机移机至下一桩位，重复步骤1～5，形成由多个微生物土搅拌桩连续搭接而成的基坑微生物土重力式围护结构。
实施例4
一种基坑微生物土重力式围护结构的施工方法，包括如下步骤：
步骤1：桩机定位，由搅拌桩机确定桩位；
步骤2：搅拌复合菌液下沉：搅拌桩机灌入菌液和固载材料，并在旋转下沉过程预搅拌复合菌液和固载材料，当喷浆口下沉至设计深度，原地喷复合菌液混合料60s；
其中，复合菌液包括浓度OD600＝1.4的巴氏芽孢杆菌、浓度OD600＝0.7的科氏芽孢杆菌和营养盐溶液，每1L的营养盐溶液中含有6.5g大豆蛋白胨、17g胰蛋白胨、4g豆粕蛋白胨、5.5g氯化钠和20g尿素，营养盐溶液的pH值为7.25；
固载材料是由质量比为7:2的秸秆纤维粉末和膨胀珍珠岩粉末混合而成；所述秸秆纤维粉末是由小麦秸秆粉碎后按料液比40ml/g加入质量浓度为1％的氢氧化钠溶液，加入8mg/L甘油混合搅拌30min，经质量浓度为0.5％的醋酸水溶液清洗，干燥后得到的疏松的秸秆纤维粉末；
复合菌液和固载材料按质量比为:1:9混合；
步骤3：搅拌复合喷菌液上升：搅拌桩机边搅拌边匀速上升，并保持喷复合菌液混合料，当喷浆口上升至设计桩顶时停止上升；
步骤4：搅拌喷胶结溶液下沉：搅拌桩机灌入胶结溶液，在旋转下沉过程搅拌胶结溶液，当喷浆口下沉至设计深度，原地喷胶结溶液60s；
其中，胶结溶液包括浓度为1.0mol/L氯化钙溶液、1.0mol/L的尿素溶液和pH＝5.5，0.05mol/L磷酸钠缓冲液；
复合菌液、胶结溶液和固载材料的质量比为：1:1:9；
步骤5：搅拌喷胶结溶液上升：搅拌桩机边搅拌边匀速上升，并保持喷胶结溶液，当喷浆口上升至设计桩顶时停止上升，搅拌5s；
步骤6：每根微生物土搅拌桩施工完成后，随即施工加筋材料，向微生物土搅拌桩桩中心压入毛竹加筋材料，毛竹加筋材料粗段朝上，细段朝下，插入深度比微生物土搅拌桩深度短1m；加筋材料直径50mm，完成加筋材料施工后，挖除桩头顶部松散破碎的部分，露出20cm加筋材料顶部，沿桩顶将加筋材料头用钢筋网连接，并用C20混凝土浇筑形成镇口板，镇口板板厚20mm，加筋材料进入混凝土镇口板不少于50mm，完成镇口板施工后，搅拌桩机或高压喷射注浆机移机至下一桩位，重复步骤1～5，形成由多个微生物土搅拌桩连续搭接而成的基坑微生物土重力式围护结构，其结构如图1、2所示。
实施例5
一种基坑微生物土重力式围护结构的施工方法，包括如下步骤：
步骤1：桩机定位，由高压喷射注浆机确定桩位；
步骤2：搅拌复合菌液下沉：高压喷射注浆机灌入菌液和固载材料，并在旋转下沉过程预搅拌复合菌液和固载材料，当喷浆口下沉至设计深度，原地喷复合菌液混合料60s；
其中，复合菌液包括浓度OD600＝1.4的巴氏芽孢杆菌、浓度OD600＝0.7的科氏芽孢杆菌和营养盐溶液，每1L的营养盐溶液中含有6.5g大豆蛋白胨、17g胰蛋白胨、4g豆粕蛋白胨、5.5g氯化钠和20g尿素，营养盐溶液的pH值为7.25；
固载材料是由质量比为6:2的秸秆纤维粉末和膨胀珍珠岩粉末混合而成；秸秆纤维粉末是由玉米秸秆粉碎后按料液比60ml/g加入质量浓度为0.5％的氢氧化钠溶液，加入5mg/L甘油混合搅拌60min，经质量浓度为1％的醋酸水溶液清洗，干燥后得到的疏松的秸秆纤维粉末；
复合菌液和固载材料按质量比为:1:9混合；
步骤3：搅拌复合喷菌液上升：高压喷射注浆机边搅拌边匀速上升，并保持喷复合菌液混合料，当喷浆口上升至设计桩顶时停止上升；
重复步骤2～3；
步骤4：搅拌喷胶结溶液下沉：高压喷射注浆机灌入胶结溶液，在旋转下沉过程搅拌胶结溶液，当喷浆口下沉至设计深度，原地喷胶结溶液60s；
其中，胶结溶液包括浓度为1.2mol/L氯化钙溶液、1.2mol/L的尿素溶液和pH＝5.5，0.05mol/L磷酸钠缓冲液；
复合菌液、胶结溶液和固载材料的质量比为：1:1:9；
步骤5：搅拌喷胶结溶液上升：高压喷射注浆机边搅拌边匀速上升，并保持喷胶结溶液，当喷浆口上升至设计桩顶时停止上升，搅拌5s；
重复步骤4～5；
步骤6：每根微生物土搅拌桩施工完成后，随即施工加筋材料，向微生物土搅拌桩桩中心压入木桩加筋材料，木桩加筋材料粗段朝上，细段朝下，插入深度比微生物土搅拌桩深度短2m；加筋材料直径100mm，完成加筋材料施工后，挖除桩头顶部松散破碎的部分，露出30cm加筋材料顶部，沿桩顶将加筋材料头用钢筋网连接，并用C20混凝土浇筑形成镇口板，镇口板板厚20mm，加筋材料进入混凝土镇口板不少于50mm，完成镇口板施工后，搅拌桩机或高压喷射注 浆机移机至下一桩位，重复步骤1～5，形成由多个微生物土搅拌桩连续搭接而成的基坑微生物土重力式围护结构。
为验证基坑微生物土重力式围护结构的物理性能，参照GB/T50082-2009《混凝土长期性能和耐久性能试验方法标准》进行室内的不同的固化微生物土块的耐久性测试试验抗剪强度测定。
微生物土块试样的制备：取含水率为50～55％的软土，采用一定的复合菌液、胶结溶液与固载材料原料，先将复合菌液、胶结溶液进行混合搅拌均匀，然后将复合菌液混合料与胶结溶液加入至软土中，搅拌均匀，并于在温度为25℃、湿度98％的恒湿恒温箱中养护，每个固化微生物土块为10×10cm正方形试样。
采用ZJ型应变控制式直剪仪测定抗剪强度，剪切速率为0.8mm/min,法向应力为100kpa，测定其剪切应力。
实验组：
采用实施例2～4中基坑微生物土重力式围护结构施工用的复合菌液、胶结溶液与固载材料原料进行上述微生物土块的制备，作为实验组1～3；
对比组：
对比组1：仅采用复合菌液、胶结溶液进行上述微生物土块的制备；未添加固载材料，其余均与实验组3相同；
对比组2：胶结溶液中未添加磷酸钠缓冲液的胶结溶液，其余均与实验组3相同。
对比组3：固载材料中的秸秆纤维粉末和膨胀珍珠岩粉末的质量比为1:1，其余与实验组3相同。
对比组4：采用单一的秸秆纤维粉末作为固载材料，其余与实验组3相同。
测试结果如下表：
Figure PCTCN2021122119-appb-000001
由上表可知，通过采用复合菌液、胶结溶液和固载材料与土体搅拌固化获得软土微生物土块具有高抗压强度、抗剪强度和抗渗透性能，其用于基坑微生物土重力式围护结构的固体固化均匀，耐久性能好。其中以实验组3的固化微生物土块的物理性能最优。
由实验组3与对比组1～4对比可看出，对比组1中未添加固载材料，其软土微生物土块的抗压、抗剪和抗渗性能均明显降低；对比组2中未添加磷酸钠缓冲液的胶结溶液其抗压强度降低，表明本发明利用添加pH＝5.5～6.8，0.05～0.1mol/L磷酸钠缓冲液的胶结溶液，有利于提高微生物活性，促进微生物生成更多的具有胶结性能的碳酸钙晶体，提高微生物固化土的抗压强度；对比组3和4中，其抗压强度也明显降低，且对比组4的抗剪强度也明显降低，表明本发明通过采用一定配比的秸秆纤维粉末和膨胀珍珠岩粉末组合作为固载材料，不仅有利提高微生物固化土的抗压强度，同时其固化结构密实度好，抗剪性强度提高。
以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。

Claims (10)

  1. 一种基坑微生物土重力式围护结构，其特征在于：该微生物土重力式围护结构是由搅拌桩机或高压喷射注浆机采用复合菌液、胶结溶液和固载材料与土体搅拌，固化形成连续搭接的微生物土柱状加固体挡墙；所述固载材料是由质量比为(5～8):(1～3)的秸秆纤维粉末和膨胀珍珠岩粉末混合而成；所述胶结溶液为含有0.05～0.1mol/L磷酸钠缓冲液的胶结溶液，所述磷酸钠缓冲液的pH值为5.5～6.8。
  2. 根据权利要求1所述的一种基坑微生物土重力式围护结构，其特征在于：所述复合菌液包括浓度OD600＝1.3～1.5的巴氏芽孢杆菌、浓度OD600＝0.6～0.8的科氏芽孢杆菌和营养盐溶液，每1L的营养盐溶液中含有6～7g大豆蛋白胨、16～18g胰蛋白胨、3～5g豆粕蛋白胨、5～6g氯化钠和19～21g尿素，营养盐溶液的pH值为7.2～7.3。
  3. 根据权利要求1所述的一种基坑微生物土重力式围护结构，其特征在于：所述胶结溶液包括浓度为0.6～1.5mol/L氯化钙溶液、0.6～1.5mol/L的尿素溶液和pH＝5.5～6.8，0.05～0.1mol/L磷酸钠缓冲液。
  4. 根据权利要求1所述的一种基坑微生物土重力式围护结构，其特征在于：所述秸秆纤维粉末是由玉米或小麦秸秆粉碎后按料液比40～60ml/g加入质量浓度为0.5～1％的氢氧化钠溶液，加入5～8mg/L甘油混合搅拌30～60min，经质量浓度为0.5～1％的醋酸水溶液清洗，干燥后得到的疏松的秸秆纤维粉末。
  5. 根据权利要求1所述的一种基坑微生物土重力式围护结构，其特征在于：所述复合菌液、胶结溶液和固载材料的质量比为1:1:(8～10)。
  6. 根据权利要求1所述的一种基坑微生物土重力式围护结构，其特征在于：所述微生物土重力式围护结构内部设有加筋材料，所述加筋材料为毛竹或木桩。
  7. 一种如权利要求1～6中任意一项所述的基坑微生物土重力式围护结构的施工方法，其特征在于：包括如下步骤：
    步骤1：桩机定位，由搅拌桩机或高压喷射注浆机确定桩位；
    步骤2：搅拌复合菌液下沉：搅拌桩机或高压喷射注浆机灌入菌液和固载材料，并在旋转下沉过程预搅拌复合菌液和固载材料，当喷浆口下沉至设计深度，原地喷复合菌液混合料60～70s；
    步骤3：搅拌复合喷菌液上升：搅拌桩机或高压喷射注浆机边搅拌边匀速上升，并保持喷复合菌液混合料，当喷浆口上升至设计桩顶时停止上升；
    步骤4：搅拌喷胶结溶液下沉：搅拌桩机或高压喷射注浆机灌入胶结溶液，在旋转下沉过程搅拌胶结溶液，当喷浆口下沉至设计深度，原地喷胶结溶液60～70s；
    步骤5：搅拌喷胶结溶液上升：搅拌桩机或高压喷射注浆机边搅拌边匀速上升，并保持喷胶结溶液，当喷浆口上升至设计桩顶时停止上升，搅拌4～6s；
    步骤6：完成单根微生物土搅拌桩施工，搅拌桩机或高压喷射注浆机移机至下一桩位，重复步骤1～5，形成由多个微生物土搅拌桩连续搭接而成的基坑微生物土重力式围护结构。
  8. 根据权利要求7所述的一种基坑微生物土重力式围护结构的施工方法，其特征在于：步骤6中，每根微生物土搅拌桩施工完成后，随即施工加筋材料，向微生物土搅拌桩桩中心压入加筋材料，加筋材料粗段朝上，细段朝下，插入深度比微生物土搅拌桩深度短1-2m；加筋材料直径根据微生物土搅拌桩直径设置，直径控制在50mm～100mm之间。
  9. 根据权利要求8所述的一种基坑微生物土重力式围护结构的施工方法，其特征在于：加筋材料施工完成后，挖除桩头顶部松散破碎的部分，露出20cm～30cm加筋材料顶部，沿桩顶将加筋材料头用钢筋网连接，并用C20混凝土浇筑形成镇口板，镇口板板厚20mm，加筋材料进入混凝土镇口板不少于50mm。
  10. 根据权利要求7所述的一种基坑微生物土重力式围护结构的施工方法，其特征在于：单根微生物土搅拌桩施工过程中，在步骤4前，还包括重复步骤2-3；在步骤6前，还包括重复步骤4-5。
PCT/CN2021/122119 2021-06-07 2021-09-30 一种基坑微生物土重力式围护结构及其施工方法 WO2022257305A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202110632921.X 2021-06-07
CN202110632921.XA CN113417295B (zh) 2021-06-07 2021-06-07 一种基坑微生物土重力式围护结构及其施工方法

Publications (1)

Publication Number Publication Date
WO2022257305A1 true WO2022257305A1 (zh) 2022-12-15

Family

ID=77787941

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/122119 WO2022257305A1 (zh) 2021-06-07 2021-09-30 一种基坑微生物土重力式围护结构及其施工方法

Country Status (2)

Country Link
CN (1) CN113417295B (zh)
WO (1) WO2022257305A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117538356A (zh) * 2023-11-10 2024-02-09 佛山市交通科技有限公司 固化搅拌桩中不同深度土壤胶结料含量的预测方法

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113417295B (zh) * 2021-06-07 2022-08-12 海南大学 一种基坑微生物土重力式围护结构及其施工方法
CN114101300B (zh) * 2021-11-08 2023-03-14 中交第二公路勘察设计研究院有限公司 一种尾砂处理方法、装置、系统及计算机可读存储介质

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080298901A1 (en) * 2004-07-28 2008-12-04 Jean-Pierre Hamelin Soil Consolidating Method and Composition Therefor
KR101030761B1 (ko) * 2010-11-24 2011-04-26 조선대학교산학협력단 미생물을 이용한 연약 지반의 고결화 방법
JP2016220586A (ja) * 2015-05-28 2016-12-28 株式会社竹中工務店 ウレアーゼ生成微生物の製造方法及び地盤改良方法
CN110130318A (zh) * 2019-05-24 2019-08-16 南京林业大学 一种微生物搅拌注浆桩的施工方法
CN110344392A (zh) * 2019-08-07 2019-10-18 南京林业大学 一种静电缓凝处理的微生物固土装置与方法
CN111454726A (zh) * 2020-04-26 2020-07-28 三峡大学 一种应用于危岩体加固的微生物胶囊及施工工艺
CN113417295A (zh) * 2021-06-07 2021-09-21 海南大学 一种基坑微生物土重力式围护结构及其施工方法

Family Cites Families (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE761001A (en) * 1970-12-29 1971-05-27 Basf Ag Water-proofing of water channels withpolystyrene
CA2530481A1 (en) * 2003-07-02 2005-01-13 Ada Foundation Remineralizing dental cements
AP2221A (en) * 2003-07-29 2011-03-24 All India Inst Med A method for diagnosis of tuberculosis by smear microscopy, culture and polymerase chain reaction using processed clinical samples and kit thereof.
JP2006022623A (ja) * 2004-07-09 2006-01-26 Kubota Corp ソイルセメント合成杭及びその施工方法
CN100340498C (zh) * 2004-09-11 2007-10-03 中国石油化工股份有限公司 一种微生物填料及其制备方法
CN101644047A (zh) * 2009-07-23 2010-02-10 东南大学 利用微生物矿化作用胶结松散砂粒的方法
JP5547444B2 (ja) * 2009-08-28 2014-07-16 株式会社ライフエンジニアリング 炭酸塩によるセメント工法
CN102071750A (zh) * 2011-01-20 2011-05-25 董阳军 不同热工区域建筑防结露围护结构
CN102276303B (zh) * 2011-06-16 2013-05-08 沈保华 植物营养素
CN104631430B (zh) * 2014-12-29 2016-06-29 南京林业大学 一种微生物注浆排水砂桩处理软土地基的方法
CN105040675B (zh) * 2015-09-14 2017-04-05 东南大学 一种砂土的微生物固化方法及其装置
CN105386433B (zh) * 2015-12-08 2017-06-16 南京林业大学 一种微生物固土cfg桩复合地基及施工方法
CN105386436B (zh) * 2015-12-08 2018-02-09 南京林业大学 一种微生物固土约束散体材料桩复合地基及施工方法
CN106760205A (zh) * 2016-11-23 2017-05-31 重庆大学 一种采用胶结微生物水泥的高强钢管约束柱
CN106884424A (zh) * 2017-04-10 2017-06-23 中国水利水电科学研究院 一种在粉细砂地层进行微生物固化的装置及施工方法
CN107326870A (zh) * 2017-07-05 2017-11-07 海南大学 一种南海岛礁吹填钙质砂土地基的处理方法
CN108461170A (zh) * 2018-04-24 2018-08-28 海南大学 一种新型高放废物深地质处置缓冲材料及其施工方法
CN108547307A (zh) * 2018-05-21 2018-09-18 北京交通大学 基于人造壤土的边坡生态防护方法
CN111393088A (zh) * 2020-04-01 2020-07-10 中国地质大学（武汉） 一种提高固井水泥浆中微生物活性的固载方法
CN111424689A (zh) * 2020-04-20 2020-07-17 中国科学院地质与地球物理研究所 一种采用磷石膏与微生物改良土质边坡抗雨水侵蚀的防护方法
CN112252293A (zh) * 2020-10-12 2021-01-22 海南大学 一种利用微生物进行固化骨料的等能量变形复合地基及施工方法
CN112813960A (zh) * 2020-12-31 2021-05-18 中国水利水电科学研究院 一种利用微生物复合纤维加筋改良膨胀土的方法
CN112746607B (zh) * 2021-01-13 2024-06-14 大连理工大学 一种电渗联合微生物诱导碳酸钙沉淀加固地基的设备及方法

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080298901A1 (en) * 2004-07-28 2008-12-04 Jean-Pierre Hamelin Soil Consolidating Method and Composition Therefor
KR101030761B1 (ko) * 2010-11-24 2011-04-26 조선대학교산학협력단 미생물을 이용한 연약 지반의 고결화 방법
JP2016220586A (ja) * 2015-05-28 2016-12-28 株式会社竹中工務店 ウレアーゼ生成微生物の製造方法及び地盤改良方法
CN110130318A (zh) * 2019-05-24 2019-08-16 南京林业大学 一种微生物搅拌注浆桩的施工方法
CN110344392A (zh) * 2019-08-07 2019-10-18 南京林业大学 一种静电缓凝处理的微生物固土装置与方法
CN111454726A (zh) * 2020-04-26 2020-07-28 三峡大学 一种应用于危岩体加固的微生物胶囊及施工工艺
CN113417295A (zh) * 2021-06-07 2021-09-21 海南大学 一种基坑微生物土重力式围护结构及其施工方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117538356A (zh) * 2023-11-10 2024-02-09 佛山市交通科技有限公司 固化搅拌桩中不同深度土壤胶结料含量的预测方法

Also Published As

Publication number Publication date
CN113417295A (zh) 2021-09-21
CN113417295B (zh) 2022-08-12

Similar Documents

Publication Publication Date Title
WO2022257305A1 (zh) 一种基坑微生物土重力式围护结构及其施工方法
CN104196131B (zh) 微生物沉积碳酸钙封堵混凝土现浇板楼板或底板裂缝方法
CN100475733C (zh) 一种黏结剂、使用该黏结剂的保温隔音材料及其制备工艺
US20210070660A1 (en) Economical high-strength quick-hardening grouting material and grouting reinforcement method for soft rock tunnel
AU2021103785A4 (en) In-situ repair method for facade surface cracks by microbially induced calcium carbonate precipitation
CN113307591B (zh) 一种多源固废复合高流态回填材料及其制备方法和应用
CN101913815B (zh) 一种用于型钢混凝土组合结构强度等级为c140的混凝土
CN103539407B (zh) 一种用于型钢混凝土组合结构c160强度等级的混凝土
CN108863201B (zh) 一种施工用保温防回潮混凝土模块及其施工方法
CN106082901B (zh) 一种加固软弱地基的绿色混凝土预制桩及施工方法
CN106884424A (zh) 一种在粉细砂地层进行微生物固化的装置及施工方法
CN101863072A (zh) 一种提升高强微膨胀混凝土性能的内养护工艺
CN107954669A (zh) 一种灌浆料及其制备方法
CN101913822A (zh) 一种用于型钢混凝土组合结构强度等级为c150的混凝土
CN101830665A (zh) 一种水下灌注桩混凝土用抗分散增强剂及其使用方法
CN105731896B (zh) 一种装配式构件高强混凝土及其制备方法和养护方法
CN110230314A (zh) 一种桩基结构及其施工方法
CN205776349U (zh) 一种独立式砖砌体抗震窑洞
CN108221876A (zh) 一种水利工程泄洪防渗水坝
CN109779011A (zh) 微生物灌浆锚固连接混凝土构件纵向钢筋的方法及结构
CN106587681B (zh) 一种绿色建筑材料-生物水泥的制备方法
CN1242126C (zh) 一种渠道接缝防滲施工方法
CN105481317B (zh) 一种用于型钢混凝土组合结构c50强度等级的混凝土
CN201258539Y (zh) 抗震保温砌块
CN113979677A (zh) 一种微生物加固纳米材料混合钙质砂制作方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21944805

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21944805

Country of ref document: EP

Kind code of ref document: A1