WO2021082767A1 - 一种基于增强纤维和偏高岭土的加压灌注桩的施工方法 - Google Patents

一种基于增强纤维和偏高岭土的加压灌注桩的施工方法 Download PDF

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Publication number
WO2021082767A1
WO2021082767A1 PCT/CN2020/115195 CN2020115195W WO2021082767A1 WO 2021082767 A1 WO2021082767 A1 WO 2021082767A1 CN 2020115195 W CN2020115195 W CN 2020115195W WO 2021082767 A1 WO2021082767 A1 WO 2021082767A1
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Prior art keywords
pile
concrete
fiber
metakaolin
soil
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PCT/CN2020/115195
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English (en)
French (fr)
Inventor
王仕俊
黄炜
李毅平
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国家电网有限公司
国网甘肃省电力公司
国网甘肃省电力公司建设分公司
国网甘肃省电力公司经济技术研究院
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Priority to AU2020376449A priority Critical patent/AU2020376449B2/en
Publication of WO2021082767A1 publication Critical patent/WO2021082767A1/zh

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Classifications

    • 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
    • E02D5/38—Concrete or concrete-like piles cast in position ; Apparatus for making same making by use of mould-pipes or other moulds
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/001—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing unburned clay
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D15/00—Handling building or like materials for hydraulic engineering or foundations
    • E02D15/02—Handling of bulk concrete specially for foundation or hydraulic engineering purposes
    • E02D15/04—Placing concrete in mould-pipes, pile tubes, bore-holes or narrow shafts
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D27/00—Foundations as substructures
    • E02D27/10—Deep foundations
    • E02D27/12—Pile foundations
    • E02D27/14—Pile framings, i.e. piles assembled to form the substructure
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D2250/00—Production methods
    • E02D2250/0023—Cast, i.e. in situ or in a mold or other formwork
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P40/00—Technologies relating to the processing of minerals
    • Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding

Definitions

  • the invention is a construction method based on reinforced fiber and geopolymer pressurized cast-in-place pile foundation, and belongs to the technical field of civil engineering.
  • Geopolymers are new types of cementing materials that use natural minerals, solid wastes, and artificial silicon-aluminum compounds as raw materials, and are called "green cementing materials in the 21st century.”
  • metakaolin which has been used as an additional material for high-strength concrete in recent years.
  • metakaolin 10%-15% instead of cement base material can increase the tensile strength of concrete by 1.3 times and the compressive strength by 2.0 times.
  • Adding a certain proportion of steel fiber to concrete can not only improve its own compressive strength, tensile strength, toughness and carbonization resistance, but also can be used in many special constructions where steel bars cannot be used to increase the strength.
  • the idea is to use steel fiber, polypropylene fiber, carbon fiber or basalt fiber and other fiber-reinforced materials to improve the characteristics of poor tensile properties and poor ductility of concrete; use geopolymers (abbreviated as geopolymers) using natural mineral metakaolin as raw materials It can improve the tensile strength, compressive strength and durability of concrete; the construction method of bored pressure grouting does not require mud wall protection, no sediment, no mud pollution, fast construction speed, low cost, and full pile body Due to its high rate, a construction method of pressurized cast-in-place pile foundation based on reinforced fiber and geopolymer is proposed.
  • the present invention provides a construction method for pressurized cast-in-place piles based on reinforced fibers and metakaolin.
  • Use fiber reinforced materials such as steel fiber, polypropylene fiber, carbon fiber or basalt fiber to improve the characteristics of poor tensile properties and poor ductility of concrete; use geopolymers (referred to as geopolymers) using natural mineral metakaolin as raw materials to improve The characteristics of concrete tensile strength, compressive strength and durability; the construction method of bored piles does not require mud wall protection, no sediment, no mud pollution, fast construction speed, low cost, and high pile filling rate.
  • the first step fixed-point laying out according to the specific pile position, the pile position measurement error is not more than 10 mm. Take the center point of the pile as the center to dig out a circular foundation pit 300 mm larger than the designed pile diameter. The depth is subject to the removal of surface construction waste and stones.
  • the steel protective tube (the diameter of the protective tube is D+200 mm, D Is the construction pile diameter) and fixed vertically at the pile position. It is required that the center deviation of the protective tube is not more than 2 cm, and the inclination is not more than 0.5%. After calibration, bury the outer side of the protective tube with plain soil to ensure that the protective tube does not float up and shift during drilling.
  • Step 2 Treat the foundation of the pile machine operation area, and the foundation bearing capacity is required to reach 160 kN/m2.
  • the bedding of the drilling rig is stable to ensure that the machine body is flat and the drill rod is vertical and stable.
  • the lower end of the drill pipe is 10-20 cm away from the ground, and the drill bit is aligned with the pile position.
  • the offset between the drill point and the pile point shall not be greater than 10 mm.
  • the verticality is controlled within 1%.
  • Step 3 Start the drill and lower the drill bit at a steady speed.
  • the drilling speed should be determined according to the soil conditions: the miscellaneous fill and coarse-grained soil should be controlled at 1.0 m/min, and the soft clay, silt, and sandy soil should be controlled at 1.5 m/min.
  • it is required not to change the rotation direction of the drilling rig or to raise the drill pipe. While rotating the drill pipe, remove the muck at the edge of the hole to prevent the soil from falling when the drill pipe is raised.
  • the theodolite should be used to correct the verticality during the drilling process ( ⁇ 1%) . Stop the drilling rig after drilling to the design elevation.
  • Step 4 Configure reinforced fiber and geopolymer concrete.
  • the geopolymer is metakaolin with a particle size of ⁇ 0.045 mm, and the blending amount is 60 ⁇ 70 kg/m3;
  • the reinforcing fiber is a steel fiber with a length of ⁇ 2 cm, and the tensile strength is required to be ⁇ 500 MPa, the elongation at break is not less than 10%, the blending amount is 15-20 kg/m3; the coarse aggregate particle size is 5-25 mm; the slump is 180 mm-220 mm; the initial setting time is ⁇ 6 hours.
  • Step 5 After lifting the drill rod 200 mm, stop lifting the drill and start to use the ground pump to transport the reinforced fiber and geopolymer concrete.
  • the maximum pressure of pumping concrete is 2 MPa, not less than 1 MPa.
  • the drill continues to be lifted at a speed of ⁇ 2 m/min, and at the same time, the concrete is pumped continuously at a pressure of 1 MPa ⁇ 2 MPa.
  • the distance between the ground pump and the drilling rig should be controlled within 60m, the concrete should be continuously mixed, and the height of the concrete in the top funnel should be ⁇ 40 cm, and the drill bit should always be buried under the concrete surface not less than 1m.
  • the filling ratio of reinforced fiber and geopolymer concrete required to be poured (the ratio of the actual volume of concrete poured to the theoretical volume of the pile calculated according to the design diameter and depth of the pile) is 1.1 to 1.2.
  • the measures of slowing down the lifting speed and increasing the grouting pressure can be used to regrouting the pile.
  • Step 6 When the poured concrete should exceed the top of the pile by 500 mm-1000 mm, the reinforcement cage shall be inserted after the anchorage length is ⁇ 100 cm, extending 100 cm from the top of the pile as the pre-embedded steel bar connected to the pile cap. Complete construction.
  • the characteristic value of single pile bearing capacity can reach 1200 kN or more;
  • the concrete is dense and has the effect of infiltration and compaction of the soil around the pile hole, which increases the pile side friction resistance, so the single pile has high bearing capacity and strong pull resistance.
  • the pile body adopts reinforced fiber, geopolymer and concrete composite materials to improve the strength of the pile body.
  • the post-insertion steel cage does not require the full length of the pile body to be laid, which is economical and simple in construction.
  • Figure 1 is a schematic diagram of the construction process of the present invention.
  • circular foundation pit 1 steel casing 2; power unit 3; hollow drill pipe 4; top cavity 5; ground pump 6; reinforced fiber and geopolymer pile 7; embedded steel bar 8.
  • the protective tube 2 to ensure the quality of the concrete construction at the top of the pile, the hollow drill rod 4 is driven by the power device 3, and the hollow drill rod 4 is rotated in the foundation soil to the design elevation of the designed pile bottom, and then the hollow drill rod 4 is rotated in the reverse direction, during the lifting process
  • the composite concrete material with added fiber and metakaolin is poured into the cavity 5 and the hollow drill rod 4 through the pressure of the ground pump 6 to form the pile body 7, and finally the pre-embedded steel bars 8 are inserted.
  • the specific steps are as follows:
  • a. Perform fixed-point laying out according to the specific pile position, and the pile position measurement error shall not exceed 10 mm.
  • the steel protective tube 2 (the diameter of the protective tube is D+200 mm , D is the diameter of the construction pile) is vertically fixed at the pile position. It is required that the center deviation of the protective tube is not more than 2 cm, and the inclination is not more than 0.5%. After calibration, bury the outer side of the protective tube with plain soil to ensure that the protective tube does not float up and shift during drilling.
  • the foundation bearing capacity is required to reach 160 kN/m2.
  • the bedding of the drilling rig is stable to ensure that the machine body is flat and the drill pipe 4 is vertical and stable.
  • the lower end of the drill rod 4 is 10-20 cm away from the ground, and the drill bit is aligned with the pile position.
  • the offset between the drill bit and the pile point shall not be greater than 10 mm.
  • the verticality is controlled within 1%.
  • the drilling speed should be determined according to the soil conditions: the miscellaneous fill and coarse-grained soil should be controlled at 1.0 m/min, and the soft clay, silt, and sandy soil should be controlled at 1.5 m/min.
  • the miscellaneous fill and coarse-grained soil should be controlled at 1.0 m/min
  • the soft clay, silt, and sandy soil should be controlled at 1.5 m/min.
  • it is required not to change the rotation direction of the drill rig or to raise the drill pipe.
  • the theodolite should be used to correct the verticality during the drilling process ( ⁇ 1%) ). Stop the drilling rig after drilling to the design elevation.
  • the geopolymer is metakaolin with a particle size of ⁇ 0.045 mm, and the blending amount is 60 ⁇ 70 kg/m3;
  • the reinforcing fiber is steel fiber, polypropylene fiber, carbon fiber or basalt fiber with a length of ⁇ 2 cm, and the tensile strength is required to be ⁇ 500 MPa, the elongation at break is not less than 10%, the blending amount is 15-20 kg/m3;
  • the coarse aggregate particle size is 5-25 mm; the slump is 180 mm-220 mm; the initial setting time is ⁇ 6 hours .
  • the maximum pressure for pumping concrete is 2 MPa, not less than 1 MPa.
  • the lift speed is ⁇ 2 m/min, and the concrete is pumped at the pressure of 1 MPa ⁇ 2 MPa at the same time.
  • the distance between the ground pump and the drilling rig should be controlled within 60m, the concrete should be continuously mixed, and the height of the concrete in the top funnel should be ⁇ 40 cm, and the drill bit should always be buried under the concrete surface not less than 1m.
  • the filling rate of reinforced fiber and geopolymer concrete required to be poured (the ratio of the actual volume of concrete poured to the theoretical volume of the pile calculated according to the design diameter and depth of the pile) is 1.1 to 1.2.
  • the construction method of a pressurized cast-in-place pile based on reinforced fibers and metakaolin of the present invention uses fiber reinforced materials such as steel fibers and geopolymer materials mainly based on metakaolin to improve the tensile performance and ductility of concrete.
  • Excavate the foundation pit on the surface remove the surface construction waste and coarse-grained soil, and ensure the quality of the concrete construction at the top of the pile through the top steel protective tube.
  • the hollow drill rod is driven by the power device to drill to the design elevation in the foundation soil, and then reverse Rotate the hollow drill rod, and during the lifting process, the composite concrete material with fiber and metakaolin is poured into the cavity on the top of the drill rod and the hollow drill rod through the pressure of the ground pump to form a pile body, and finally the embedded steel is inserted.
  • It has the advantages of no need for mud wall protection, no sediment, no mud pollution, fast construction speed, low cost, high pile filling rate, and no post-insertion steel cage. It is suitable for pile foundations whose pile diameter is 400 ⁇ 800mm and the drilling depth is less than 30 m.

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Abstract

本发明公开了一种基于增强纤维和偏高岭土的加压灌注桩的施工方法，利用钢纤维等纤维增强材料，以及以偏高岭土为主的地质聚合物材料，改善混凝土的抗拉性能和延性，通过在表面开挖基坑，清除表面建筑垃圾与粗颗粒土，通过顶部钢制护筒，保证桩顶部混凝土施工质量，通过动力装置带动空心钻杆，在地基土中进行钻至设计标高，然后反向旋转空心钻杆，提升的过程中通过地泵加压将添加纤维与偏高岭土的复合混凝土材料灌入钻杆顶部空腔和空心钻杆，形成桩体，最后插入预埋钢筋。具有不需要泥浆护壁，无沉渣，无泥浆污染，施工速度快，造价较低，桩体充盈率高、无后插钢筋笼的优点。适用于桩直径要求为400～800mm，钻孔深度30 m以内的桩基础。

Description

一种基于增强纤维和偏高岭土的加压灌注桩的施工方法 技术领域
本发明是一种基于增强纤维和地聚合物加压灌注桩基础的施工方法，属于土木工程技术领域。
 背景技术
普通泥浆护壁钻孔灌注桩存在工艺繁杂、桩体混凝土质量及承载力的稳定性差，质量事故概率高，泥皮的润滑效应及孔底沉渣的软垫效应又造成桩承载力低，施工效率低，泥浆污染生态环境等缺点。为克服普通钻孔灌注桩存在的上述问题，我国从20世纪90年代开始在长螺旋钻孔灌注桩基础上进行创新，如1999年曹增国等提出的《螺旋提土压灌水泥砂浆桩复合地基及其施工技术》（公开号：CN 1233696A）, 通过长螺旋钻机钻孔至设计标高，用混凝土输送泵通过钻头向孔内输送水泥砂浆形成桩体，该类桩由于桩侧无泥皮，桩底无沉渣，较大幅度地提高了桩承载力。在国外，采用上述桩型已有30多年的历程，但尚无科学的插筋方法，同时，由于目前的质量检验方法与工艺不完全适合，影响了该技术的推广应用。
地质聚合物是以天然矿物、固体废弃物以及人工硅铝化合物等为原材料的新型胶凝材料，被称为“21世纪的绿色胶凝材料”。其中，在土木工程领域内应用最为广泛的地聚合物为偏高岭土（metakaolin），近年来开始用于高强混凝土的外加材料。根据研究表明，偏高岭土10%-15%替代水泥基材，可以提高混凝土抗拉强度1.3倍，抗压强度2.0倍。混凝土中掺加一定比例的钢纤维，不仅可以提高自身的抗压强度、抗拉强度、韧性和抗碳化性能，而且可以应用于许多无法用钢筋来提升强度的特殊工程施工。
围绕如下思路：利用钢纤维、聚丙烯纤维、碳纤维或玄武岩纤维等纤维增强材料，改善混凝土的抗拉性能差、延性差的特点；利用以天然矿物偏高岭土为原材料的地质聚合物（简称地聚合物），提高混凝土的抗拉强度、抗压强度和耐久性的特点；利用钻孔压灌桩施工方法不需要泥浆护壁，无沉渣，无泥浆污染，施工速度快，造价较低，桩体充盈率高的特点，提出一种基于增强纤维和地聚合物的加压灌注桩基础的施工方法。
 技术解决方案
为了解决传统灌注成桩质量低，施工工程泥浆污染，工艺复杂，造价高的缺点，本发明提供一种基于增强纤维和偏高岭土的加压灌注桩的施工方法。
本发明的目的是采用以下技术方案实现的：
利用钢纤维、聚丙烯纤维、碳纤维或玄武岩纤维等纤维增强材料，改善混凝土的抗拉性能差、延性差的特点；利用以天然矿物偏高岭土为原材料的地质聚合物（简称地聚合物），提高混凝土的抗拉强度、抗压强度和耐久性的特点；利用钻孔压灌桩施工方法不需要泥浆护壁，无沉渣，无泥浆污染，施工速度快，造价较低，桩体充盈率高的特点，提出一种基于增强纤维和地聚合物的加压灌注桩基础。该基础适用于桩直径要求为400～800mm，钻孔深度30 m以内的桩基础。
具体操作步骤如下：
第一步：根据具体桩位进行定点放线，桩位测量误差不大于10 mm。以桩位中心点为圆心挖出比设计桩径大300 mm的圆形基坑，深度以清除表面建筑垃圾和石块为准，将钢制护筒（护筒直径为D+200 mm，D为施工桩径）垂直固定于桩位处。要求护筒中心偏差不大于2 cm，倾斜度不大于0.5 ％。校正后用素土将护筒外侧埋实，确保护筒在钻进中不发生上浮移位。
第二步：对桩机作业区域地基进行处理，要求地基承载力达到160 kN/m2。钻机铺垫平稳，确保机身平整，钻杆垂直稳定牢固。钻杆下端距地面10～20 cm，钻头对准桩位。钻尖与桩点偏移不得大于10 mm。垂直度控制在1 %以内。
第三步：启动钻机，以平稳速度下降钻头。钻进的速度应根据土层情况确定：杂填土、粗粒土控制在1.0 m/min，软黏土、粉土、砂土控制在1.5 m/min。施工过程中要求不转换钻机旋转方向或提升钻杆，边旋转钻杆边清除孔边渣土，以防止提升钻杆时土块掉入，钻孔过程要用经纬仪校正垂直度（≤1%）。钻至设计标高后停止钻机掘进。
第四步：配置增强纤维和地聚合物混凝土。其中地聚合物为粒径≤0.045 mm的偏高岭土，掺入量为60~70 kg/m3；增强纤维为长度≤2 cm的钢纤维，要求抗拉强度≥500 MPa，断裂伸长率不小于10%，掺入量为15~20 kg/m3; 粗骨料粒径为5～25 mm；坍落度为180 mm～220 mm；初凝时间≥6小时。
第五步：上提钻杆200 mm后停止提钻，开始使用地泵输送增强纤维和地聚合物混凝土。泵送混凝土的最大压力为2 MPa，并不小于1 MPa。当泵入的混凝土使钻杆埋入混凝土液面至少达500 mm后，开始继续提钻，提升速度为≤2 m/min，并同时在1 MPa~2 MPa压力下继续泵送混凝土。泵送过程中，地泵与钻机距离控制在60m以内，混凝土应连续搅拌，保持顶部漏斗内混凝土的高度≥40 cm，并保证钻头始终埋在混凝土面以下不小于1 m。要求灌注的增强纤维和地聚合物混凝土充盈率(实际灌注的混凝土方量与根据桩身设计直径和深度计算出来的桩身理论体积之比)为1.1~1.2。当灌入压力低于静止侧压力σx=K0γz(其中σx为土体的水平向压力，K0为静止侧压力系数，γ为土的重度，z为土的深度)，且充盈系数同时小于1，则说明该部位有可能发生了缩径现象。此时，可采用减慢提升速度，增大注浆压力的措施对该段桩体进行重新注浆。
第六步：当灌入的混凝土应超出桩顶500 mm-1000mm，后插钢筋笼，满足锚固长度≥100 cm，伸出桩顶部100 cm，作为与承台连接的预埋钢筋。完成施工。
 有益效果
本发明的有益效果是：
（1）单桩承载力特征值可达到1200 kN以上；
（2）受地下水位和复杂地质情况影响较小，能在有软土、流砂层、砂卵石层、有地下水等复杂地质条件下成桩；
（3）不需要设置泥浆池和沉淀池，减少了临时用地，没有泥浆污染，符合环境保护和绿色施工技术标准要求；
（4）混凝土密实，并对桩孔周围土有渗透、挤密作用，提高的桩侧摩阻力，因此单桩承载力高，抗拔能力强。
（5）桩身采用增强纤维、地聚合物和混凝土复合材料，提高桩身的强度，后插钢筋笼不需要桩身全长布设，经济性高，施工方法简易。
 附图说明
图1 是本发明的施工工艺流程示意图。
其中：圆形基坑1；钢制护筒2；动力装置3；空心钻杆4；顶端空腔5；地泵6；增强纤维和地聚合物桩体7；预埋钢筋8。
 本发明的实施方式
利用纤维增强材料与天然矿物偏高岭土，改善混凝土的抗拉性能和延性，结合钻孔加压灌注桩施工方法，通过在表面开挖基坑1，清除表面建筑垃圾与粗颗粒土，通过钢制护筒2，保证桩顶部混凝土施工质量，通过动力装置3带动空心钻杆4，在地基土中进行正向旋转至设计桩底部的设计标高，然后反向旋转空心钻杆4，提升的过程中通过地泵6加压将添加纤维与偏高岭土的复合混凝土材料灌入空腔5和空心钻杆4，形成桩体7，最后插入预埋钢筋8。如图1所示，具体工序如下：
a、根据具体桩位进行定点放线，桩位测量误差不大于10 mm。以桩位中心点为圆心挖出比设计桩径大300 mm的圆形基坑1，深度以清除表面建筑垃圾和石块为准，将钢制护筒2（护筒直径为D+200 mm，D为施工桩径）垂直固定于桩位处。要求护筒中心偏差不大于2 cm，倾斜度不大于0.5 ％。校正后用素土将护筒外侧埋实，确保护筒在钻进中不发生上浮移位。
b、对桩机作业区域地基进行处理，要求地基承载力达到160 kN/m2。钻机铺垫平稳，确保机身平整，钻杆4垂直稳定牢固。钻杆4下端距地面10～20 cm，钻头对准桩位。钻头与桩点偏移不得大于10 mm。垂直度控制在1 %以内。
c、启动动力装置3，以平稳速度下降钻杆4。钻进的速度应根据土层情况确定：杂填土、粗粒土控制在1.0 m/min，软黏土、粉土、砂土控制在1.5 m/min。施工过程中要求不转换钻机旋转方向或提升钻杆，边旋转钻杆4边清除孔边渣土，以防止提升钻杆时土块掉入，钻孔过程要用经纬仪校正垂直度（≤1%）。钻至设计标高后停止钻机掘进。
d、配置增强纤维和地聚合物混凝土。其中地聚合物为粒径≤0.045 mm的偏高岭土，掺入量为60~70 kg/m3；增强纤维为长度≤2 cm的钢纤维、聚丙烯纤维、碳纤维或玄武岩纤维，要求抗拉强度≥500 MPa，断裂伸长率不小于10%，掺入量为15~20 kg/m3; 粗骨料粒径为5～25 mm；坍落度为180 mm～220 mm；初凝时间≥6小时。
e、上提钻杆200 mm后停止提升空心钻杆4，开始使用地泵6输送增强纤维和地聚合物混凝土至空腔5和空心钻杆4，形成桩体7。泵送混凝土的最大压力为2 MPa，并不小于1 MPa。当泵入的混凝土使钻杆埋入混凝土液面至少达500 mm后，开始继续提钻，提升速度为≤2 m/min，并同时在1 MPa~2 MPa压力下继续泵送混凝土。泵送过程中，地泵与钻机距离控制在60m以内，混凝土应连续搅拌，保持顶部漏斗内混凝土的高度≥40 cm，并保证钻头始终埋在混凝土面以下不小于1 m。要求灌注的增强纤维和地聚合物混凝土充盈率(实际灌注的混凝土方量与根据桩身设计直径和深度计算出来的桩身理论体积之比)为1.1~1.2。当灌入压力低于静止侧压力σx=K0γz(其中σx为土体的水平向压力，K0为静止侧压力系数，γ为土的重度，z为土的深度)，且充盈系数同时小于1，则说明该部位有可能发生了缩径现象。此时，可采用减慢提升速度，增大注浆压力的措施对该段桩体进行重新注浆。
f、当灌入的混凝土应超出桩顶500 mm-1000mm，后插预埋钢筋8，满足锚固长度≥100 cm，伸出桩顶部100 cm，作为与承台连接的预埋钢筋。完成施工。
本发明的一种基于增强纤维和偏高岭土的加压灌注桩的施工方法，利用钢纤维等纤维增强材料，以及以偏高岭土为主的地质聚合物材料，改善混凝土的抗拉性能和延性，通过在表面开挖基坑，清除表面建筑垃圾与粗颗粒土，通过顶部钢制护筒，保证桩顶部混凝土施工质量，通过动力装置带动空心钻杆，在地基土中进行钻至设计标高，然后反向旋转空心钻杆，提升的过程中通过地泵加压将添加纤维与偏高岭土的复合混凝土材料灌入钻杆顶部空腔和空心钻杆，形成桩体，最后插入预埋钢筋。具有不需要泥浆护壁，无沉渣，无泥浆污染，施工速度快，造价较低，桩体充盈率高、无后插钢筋笼的优点。适用于桩直径要求为400～800mm，钻孔深度30 m以内的桩基础。
最后应说明的是：以上所述仅为本发明的优选实施例而已，并不用于限制本发明，尽管参照前述实施例对本发明进行了详细的说明，对于本领域的技术人员来说，其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换。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 (2)

  1. 一种基于增强纤维和偏高岭土的加压灌注桩的施工方法，其特征在于，该施工方法如下：
    1）根据具体桩位进行定点放线，桩位测量误差不大于10 mm，以桩位中心点为圆心挖出比设计桩径大300 mm的圆形基坑，深度以清除表面建筑垃圾和石块为准，将钢制护筒（护筒直径为D+200 mm，D为施工桩径）垂直固定于桩位处；要求护筒中心偏差不大于2 cm，倾斜度不大于0.5 ％；校正后用素土将护筒外侧埋实，确保护筒在钻进中不发生上浮移位；
    2）对桩机作业区域地基进行处理，要求地基承载力达到160 kN/m2；钻机铺垫平稳，确保机身平整，钻杆垂直稳定牢固；钻杆下端距地面10～20 cm，钻头对准桩位，钻尖与桩点偏移不得大于10 mm，垂直度控制在1 %以内；
    3）启动钻机，以平稳速度下降钻头，钻进的速度应根据土层情况确定：杂填土、粗粒土控制在1.0 m/min，软黏土、粉土、砂土控制在1.5 m/min；施工过程中要求不转换钻机旋转方向或提升钻杆，边旋转钻杆边清除孔边渣土，以防止提升钻杆时土块掉入，钻孔过程要用经纬仪校正垂直度（≤1%），钻至设计标高后停止钻机掘进；
    4）配置增强纤维和地聚合物混凝土；其中地聚合物为粒径≤0.045 mm的偏高岭土，掺入量为60~70 kg/m3；增强纤维为长度≤2 cm的钢纤维，要求抗拉强度≥500 MPa，断裂伸长率不小于10%，掺入量为15~20 kg/m3; 粗骨料粒径为5～25 mm；坍落度为180 mm～220 mm；初凝时间≥6小时；
    5）上提钻杆200 mm后停止提钻，开始使用地泵输送增强纤维和地聚合物混凝土；泵送混凝土的最大压力为2 MPa，并不小于1 Mpa；当泵入的混凝土使钻杆埋入混凝土液面至少达500 mm后，开始继续提钻，提升速度为≤2 m/min，并同时在1 MPa~2 MPa压力下继续泵送混凝土；泵送过程中，地泵与钻机距离控制在60m以内，混凝土应连续搅拌，保持顶部漏斗内混凝土的高度≥40 cm，并保证钻头始终埋在混凝土面以下不小于1 m；要求灌注的增强纤维和地聚合物混凝土充盈率为1.1~1.2；当灌入压力低于静止侧压力σx=K0γz(其中σx为土体的水平向压力，K0为静止侧压力系数，γ为土的重度，z为土的深度)，且充盈系数同时小于1，则说明该部位有可能发生了缩径现象，此时，可采用减慢提升速度，增大注浆压力的措施对该段桩体进行重新注浆；
    6）当灌入的混凝土应超出桩顶500 mm-1000mm，后插钢筋笼，满足锚固长度≥100 cm，伸出桩顶部100 cm，作为与承台连接的预埋钢筋，完成施工。
  2. 根据权利要求1所述的基于增强纤维和偏高岭土的加压灌注桩的施工方法，其特征在于，所述的桩体（7）材料包括：地聚合物为粒径≤0.045 mm的偏高岭土，掺入量为60~70 kg/m3；增强纤维为长度≤2 cm的钢纤维，要求抗拉强度≥500 MPa，断裂伸长率不小于10%，掺入量为15~20 kg/m3; 粗骨料粒径为5～25 mm；坍落度为180 mm～220 mm；初凝时间≥6小时。
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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CN114182721A (zh) * 2021-12-22 2022-03-15 新疆路桥建设集团有限公司 一种湿陷性黄土地段筏板承托护筒钻孔灌注桩施工方法
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110924383A (zh) * 2019-10-31 2020-03-27 国家电网有限公司 一种基于增强纤维和偏高岭土的加压灌注桩的施工方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011087304A2 (ko) * 2010-01-13 2011-07-21 전남대학교산학협력단 복합 알칼리 활성화제를 포함하는 무시멘트 알칼리 활성결합재, 이를 이용한 모르타르 또는 콘크리트
CN108677932A (zh) * 2018-05-29 2018-10-19 河北建设勘察研究院有限公司 一种桩身可加热的赤泥粉煤灰地质聚合物桩的施工方法
CN108675699A (zh) * 2018-06-11 2018-10-19 浙江大学 一种耐腐蚀地聚合物混凝土灌注桩材料及其制备方法与施工工艺
CN110255996A (zh) * 2019-07-22 2019-09-20 北京慕湖房地产开发股份有限公司 一种粉煤灰地聚物混凝土及其制备方法
CN110924383A (zh) * 2019-10-31 2020-03-27 国家电网有限公司 一种基于增强纤维和偏高岭土的加压灌注桩的施工方法

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1476543A (en) * 1975-02-10 1977-06-16 Turzillo L Apparatus for and method of forming a pile or the like in situ
CN104631438B (zh) * 2015-01-27 2016-08-24 安徽同济建设集团有限责任公司 长螺旋钻孔压灌混凝土抗拔桩施工方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011087304A2 (ko) * 2010-01-13 2011-07-21 전남대학교산학협력단 복합 알칼리 활성화제를 포함하는 무시멘트 알칼리 활성결합재, 이를 이용한 모르타르 또는 콘크리트
CN108677932A (zh) * 2018-05-29 2018-10-19 河北建设勘察研究院有限公司 一种桩身可加热的赤泥粉煤灰地质聚合物桩的施工方法
CN108675699A (zh) * 2018-06-11 2018-10-19 浙江大学 一种耐腐蚀地聚合物混凝土灌注桩材料及其制备方法与施工工艺
CN110255996A (zh) * 2019-07-22 2019-09-20 北京慕湖房地产开发股份有限公司 一种粉煤灰地聚物混凝土及其制备方法
CN110924383A (zh) * 2019-10-31 2020-03-27 国家电网有限公司 一种基于增强纤维和偏高岭土的加压灌注桩的施工方法

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