CN103938637B - Rigid-flexible combined pile foundation pit supporting construction method for hard-layer soft soil geology - Google Patents

Rigid-flexible combined pile foundation pit supporting construction method for hard-layer soft soil geology Download PDF

Info

Publication number
CN103938637B
CN103938637B CN201410164052.2A CN201410164052A CN103938637B CN 103938637 B CN103938637 B CN 103938637B CN 201410164052 A CN201410164052 A CN 201410164052A CN 103938637 B CN103938637 B CN 103938637B
Authority
CN
China
Prior art keywords
pile
concrete
rigid
flexible
reinforcing cage
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Fee Related
Application number
CN201410164052.2A
Other languages
Chinese (zh)
Other versions
CN103938637A (en
Inventor
朱奎
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangdong Keyi Xintai Building Science And Technology Development Co Ltd
Original Assignee
Individual
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 Individual filed Critical Individual
Priority to CN201410164052.2A priority Critical patent/CN103938637B/en
Publication of CN103938637A publication Critical patent/CN103938637A/en
Application granted granted Critical
Publication of CN103938637B publication Critical patent/CN103938637B/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Landscapes

  • Piles And Underground Anchors (AREA)

Abstract

The invention discloses a foundation pit supporting construction method for a rigid-flexible combined pile in a hard-layer soft soil geology. And (3) utilizing a rotary drilling hole to penetrate through the hard interlayer, pumping out concrete from the bottom of the drill bit by virtue of the rotary blade when drilling to the designed depth, and simultaneously pouring and lifting the drill rod to the ground so as to form the pump pressure plain concrete pile. And then, hoisting the connected vibration device, the high-rigidity core pipe and the steel reinforcement cage, inserting the lower end of the steel reinforcement cage into the concrete pile body, and driving the high-rigidity core pipe to vibrate the lower end of the steel reinforcement cage by means of gravity and the vibration device to enable the steel reinforcement cage to sink to the designed depth, so that the rigid pile is formed. The flexible pile is constructed firstly, then the rigid pile is constructed, the rigid pile and the flexible pile are arranged in a meshed mode to form a waterproof curtain, and the rigid pile not only plays a role in water stopping, but also plays a role in slope protection.

Description

夹硬层软土地质刚柔组合桩基坑支护施工方法Construction method of rigid-flexible combined pile foundation pit support in soft soil with interlayer hard layer

技术领域technical field

本发明涉及一种基坑支护的施工方法,特别涉及一种夹硬层软土地质刚柔组合桩基坑支护施工方法。The invention relates to a construction method for foundation pit support, in particular to a construction method for foundation pit support with rigid-flexible combination piles in soft soil interlayer.

背景技术Background technique

软土地区止水帷幕常常采用水泥土搅拌桩或者旋喷桩,但在遇到碎石、卵石等地层,水泥土搅拌桩或者旋喷桩钻头不能穿透硬层从而不能达到设计深度。传统基坑支护方法通常采用止水帷幕和护坡桩分离设置的方法,止水帷幕一般设在外侧,护坡桩再设在内侧,桩的数量会很多,基坑支护成本较高。本发明对此进行了改进,柔性桩置于相邻刚性桩的中间,一方面柔性桩和刚性桩协同变形作为支护结构,另一方面柔性桩和刚性桩咬合后形成止水帷幕,止水效果可靠。从经济角度考虑,显然桩数量比传统要低的多,从而节省了工程造价。Water-stop curtains in soft soil areas often use cement-soil mixing piles or rotary grouting piles. However, when encountering gravel, pebbles and other strata, the drill bits of cement-soil mixing piles or rotary grouting piles cannot penetrate hard layers and cannot reach the design depth. The traditional foundation pit support method usually adopts the method of separately setting the water-stop curtain and the slope protection pile. The water-stop curtain is generally set on the outside, and the slope protection pile is set on the inside. The number of piles will be large, and the cost of foundation pit support will be high. The present invention improves this. The flexible pile is placed in the middle of adjacent rigid piles. On the one hand, the flexible pile and the rigid pile cooperate to deform as a support structure; The effect is reliable. From an economic point of view, it is obvious that the number of piles is much lower than the traditional one, thus saving the project cost.

发明内容Contents of the invention

本发明所要解决的技术问题是提供一种夹硬层软土地质刚柔组合桩基坑支护施工方法,解决传统基坑造价高的问题。The technical problem to be solved by the present invention is to provide a construction method for foundation pit support of rigid-flexible combined piles in interlayer soft soil, which solves the problem of high cost of traditional foundation pits.

本发明工艺原理采用如下:Process principle of the present invention adopts as follows:

利用回旋钻孔穿过硬夹层,钻到设计深度时,借助回旋叶片切割软土,边旋转喷水泥浆边提钻杆,从而形成柔性桩。利用回旋钻孔穿过硬夹层,钻到设计深度时,借助回旋叶片将混凝土由钻头底部泵出,边灌注边提钻杆到地面,从而形成泵压素混凝土桩。随后吊起连接好的振动装置、大刚度芯管及钢筋笼,把钢筋笼下端插入混凝土桩体中,依靠重力和振动装置带动大刚度芯管对钢筋笼下端进行振动,使钢筋笼下沉至设计深度,从而形成刚性桩。先施工柔性桩,然后施工刚性桩,刚性桩和柔性桩咬合布置,形成止水帷幕,刚性桩不仅起到止水的效果,还起到了护坡的作用。Use rotary drilling to pass through the hard interlayer, and when drilling to the designed depth, use the rotary blade to cut the soft soil, and lift the drill pipe while rotating the grout to form a flexible pile. Use rotary drilling to pass through the hard interlayer, and when drilling to the design depth, pump the concrete from the bottom of the drill bit with the help of rotary blades, and lift the drill pipe to the ground while pouring, thus forming a pumped plain concrete pile. Then lift the connected vibrating device, high rigidity core tube and reinforcement cage, insert the lower end of the reinforcement cage into the concrete pile, rely on the gravity and the vibration device to drive the high rigidity core tube to vibrate the lower end of the reinforcement cage, so that the reinforcement cage sinks to Design the depth so that a rigid pile is formed. The flexible piles are constructed first, and then the rigid piles are constructed. The rigid piles and flexible piles are occluded and arranged to form a water-stop curtain. The rigid piles not only play the role of water-stop, but also play the role of slope protection.

本发明施工步骤包括:Construction steps of the present invention include:

1测量放线定位1. Measurement and setting-out positioning

清理施工场地后,应复测甲方提供的基点和基线,确定无误后,再根据基点和基线放出具体桩位,桩位测放顺序按施工顺序进行,桩位应固定好,桩中心线偏差小10mm,并做好测量记录,准确无误后方可施工。After cleaning the construction site, the base point and baseline provided by Party A should be retested. After confirming that they are correct, the specific pile positions should be released according to the base point and baseline. The minimum is 10mm, and the measurement record should be done well, and the construction can only be carried out after it is accurate.

2钻机就位2 rigs in place

钻机应保持平稳,确保施工中不发生任何倾斜移动。为准确控制钻孔深度,应在机架上设置控制标尺,以便观测。The drilling rig should be kept stable to ensure that no tilting movement occurs during construction. In order to accurately control the drilling depth, a control scale should be set on the frame for observation.

3钻机引孔3 drilling rig lead hole

桩垂直度达不到要求,桩下部止水帷幕会出现渗漏,达不到止水的效果。为了控制桩垂直度,采取如下措施:在钻机桩架的滑道上,设置两个具有定向作用的护筒,内径仅大于钻杆直径10mm,解决了钻杆的摩擦与摆动问题。在挺杆底部设置自制重力垂直度仪。桩位对中后,在挺杆底部垫枕木并压实,保证在挺杆受力摆动时,靠钻机绕轴自锁装置和挺杆与枕木产生的摩擦力抵抗摆动,使桩位不产生变化。在桩中心对位、钻杆调垂直度后,用经纬仪再检测钻杆垂直度,并在钻孔过程中随时监测,确保定位误差小于5mm,施工误差小于10mm。If the verticality of the pile does not meet the requirements, the water-stop curtain at the bottom of the pile will leak, and the water-stop effect will not be achieved. In order to control the verticality of the pile, the following measures are taken: on the slideway of the pile frame of the drilling rig, two casings with directional function are installed, and the inner diameter is only 10mm larger than the diameter of the drill pipe, which solves the problem of friction and swing of the drill pipe. Set up a self-made gravity verticality instrument at the bottom of the tappet. After the pile position is centered, put a sleeper on the bottom of the tappet and compact it to ensure that when the tappet swings under force, the self-locking device around the axis of the drilling rig and the friction generated by the tappet and the sleeper resist the swing, so that the pile position does not change. . After aligning the pile center and adjusting the verticality of the drill pipe, use theodolite to check the verticality of the drill pipe again, and monitor it at any time during the drilling process to ensure that the positioning error is less than 5mm and the construction error is less than 10mm.

4边钻进泵送水泥浆4 side drilling pumping cement slurry

钻到预定深度后,必须在孔底处进行空转清土,然后停止转动,边泵送水泥浆边提钻至地面,提钻时进行匀速转动,使泵送水泥浆和土均匀拌合,形成柔性桩。软土层钻进速度为0.8~1m/min,硬夹层部位钻进速度要放慢,钻进速度为0.2~0.4m/min,如果钻机出现摇晃现象则钻进速度还要放慢。After drilling to the predetermined depth, it must be idling at the bottom of the hole to clear the soil, then stop the rotation, lift the drill to the ground while pumping the cement slurry, and rotate at a constant speed when lifting the drill to make the pumped cement slurry and soil evenly mixed to form a Flexible pile. The drilling speed in the soft soil layer is 0.8-1m/min, and the drilling speed in the hard interlayer should be slowed down, and the drilling speed is 0.2-0.4m/min. If the drilling rig shakes, the drilling speed should be slowed down.

5压灌混凝土5 pressure poured concrete

柔性桩施工完毕后马上在刚性桩设计部位钻孔,钻到预定深度后,必须在孔底处进行空转清土,然后停止转动,边泵送混凝土边提钻至地面,提钻时不得转动,并保持匀速提升,确保钻头始终埋在混凝土中,防止断桩。由于刚性桩和柔性桩咬合部位可能会有一定的强度,钻进速度要放慢,软土层钻进速度为0.5~0.7m/min,硬夹层部位钻进速度还要放慢,钻进速度为0.1~0.3m/min,如果钻机出现摇晃现象则钻进速度再放慢。Immediately after the completion of the construction of the flexible pile, drill the hole at the design position of the rigid pile. After drilling to the predetermined depth, the soil must be idly cleared at the bottom of the hole, and then stop the rotation. Lift the drill to the ground while pumping the concrete. Do not rotate when lifting the drill. And keep lifting at a constant speed to ensure that the drill bit is always buried in the concrete to prevent the pile from breaking. Since the occlusal part of rigid pile and flexible pile may have certain strength, the drilling speed should be slowed down. It is 0.1~0.3m/min. If the drilling rig shakes, the drilling speed will be slowed down.

6插入钢筋笼6 Insert the reinforcement cage

浇筑混凝土后,通过振动装置将钢筋笼插入混凝土,形成刚性桩。振动装置采用中低频率振动锤,并安装了隔振装置;振动锤顶部有一个吊环,用于起吊振动装置和大刚度芯管;钢筋笼对正圈是用来固定和对正钢筋笼的;吊绳系于振动锤上,用于吊车起吊,同时用人来操纵确保钢筋笼安放的垂直度;振动锤下部及钢筋笼上焊有2个~4个钢环,穿入钢丝绳卡紧,起吊钢筋笼并定位。大刚度芯管用法兰盘连接在振动装置上,大刚度芯管下端压在钢筋笼末端,钢筋笼上端与振动装置柔性连接,大刚度芯管下端开口,中部、上部开通气孔。After the concrete is poured, the steel cage is inserted into the concrete by a vibrating device to form a rigid pile. The vibrating device adopts a medium and low frequency vibrating hammer, and a vibration isolating device is installed; there is a lifting ring on the top of the vibrating hammer, which is used to lift the vibrating device and the high-rigidity core tube; the steel cage alignment ring is used to fix and align the steel cage; The sling is tied to the vibrating hammer and used for lifting by a crane. At the same time, people are used to operate it to ensure the verticality of the reinforcement cage; 2 to 4 steel rings are welded on the lower part of the vibrating hammer and the reinforcement cage, which are inserted into the wire rope and clamped to lift the reinforcement. Cage and position. The high-rigidity core tube is connected to the vibrating device with a flange, the lower end of the high-rigidity core tube is pressed against the end of the steel cage, the upper end of the steel cage is flexibly connected to the vibrating device, the lower end of the high-rigidity core tube is open, and air holes are opened in the middle and upper parts.

7做桩顶混凝土压顶梁7 Make pile top concrete pressure beam

桩顶混凝土压顶梁强度采用C25或者C30,桩顶混凝土压顶梁在锚杆部位设置预留孔,以便于钻机进行钻孔。The strength of the pile top concrete pressure beam is C25 or C30, and the pile top concrete pressure beam is provided with a reserved hole at the anchor rod to facilitate drilling by the drilling rig.

8锚杆施工8 Anchor construction

采用潜孔钻机根据设计倾角进行钻孔,孔距误差不大于150mm,孔深误差不大于50mm。钻孔完成后用灰浆泵向孔内灌注水泥浆,注浆压力为0.1~0.2MPa。注浆时注浆管应插入距孔底约100mm处,随水泥浆注入缓缓拔出,至钻孔饱满为止。然后将钢筋杆体插入注满水泥浆的钻孔中。The down-the-hole drilling rig is used to drill holes according to the design inclination, the error of the hole distance is not greater than 150mm, and the error of the hole depth is not greater than 50mm. After the drilling is completed, use a mortar pump to pour cement slurry into the hole, and the grouting pressure is 0.1-0.2MPa. When grouting, the grouting pipe should be inserted about 100mm from the bottom of the hole, and slowly pulled out with the grout injection until the borehole is full. The rebar body is then inserted into the drilled hole filled with grout.

9第一次喷射混凝土9 Shotcrete for the first time

埋设控制厚度标志的φ6短钢筋,用高压水冲洗边坡,湿润边坡表面。先将水泥、砂、碎石按配合比干拌均匀后再过筛装入喷射机,然后开始喷射第一层混凝土。喷射作业应分段分片、自上而下依次进行,喷射时喷头与受喷面应垂直,保持0.8m~1.0m的距离,喷射手持喷枪做均匀旋转运动,以保证喷射出的混凝土密实均匀。同时控制好水灰比,回弹率不应大于15%,喷射混凝土终凝2h后喷水养护。Bury short φ6 steel bars with thickness control marks, wash the slope with high-pressure water, and moisten the surface of the slope. First dry mix the cement, sand and gravel according to the mixing ratio, then sieve and load them into the spraying machine, and then start spraying the first layer of concrete. The spraying operation should be carried out in sections and pieces, from top to bottom. When spraying, the nozzle should be perpendicular to the surface to be sprayed, keeping a distance of 0.8m ~ 1.0m, and the hand-held spray gun should be rotated evenly to ensure that the sprayed concrete is dense and uniform. . At the same time, the water-cement ratio should be well controlled, the rebound rate should not be greater than 15%, and the sprayed concrete should be sprayed with water for curing after 2 hours of final setting.

10挂钢丝网10 hanging wire mesh

用细铁丝将经调直的φ6钢筋绑扎成钢筋网片,钢筋网的交叉点应绑扎结实。Bind the straightened φ6 steel bars into steel mesh sheets with thin iron wires, and the intersection points of the steel mesh should be tied firmly.

11第二次喷射混凝土11 Second shotcrete

用高压水将第一层喷射混凝土面冲洗干净并湿润表面。第二层混凝土喷射顺序和操作方法与第一层相同。开始喷射时应减小喷头与受喷面的距离,并调整喷射角度,以保证第二层喷射混凝土的密实性。喷射中若有被钢筋网架住出现混凝土脱落应及时清除。喷射人员应调整喷枪的供水阀门,控制水灰比,使混凝土表面平整,湿润光泽,无流淌干斑现象。喷射混凝土终凝2h后喷水养护7d。每天喷水的次数应能保持喷射混凝土表面湿润。Rinse off the first coat of shotcrete with high pressure water and wet the surface. The second layer of concrete spraying sequence and operation method is the same as the first layer. When starting to spray, the distance between the nozzle and the sprayed surface should be reduced, and the spray angle should be adjusted to ensure the compactness of the second layer of sprayed concrete. If the concrete falls off due to being supported by the steel mesh during spraying, it should be removed in time. Spraying personnel should adjust the water supply valve of the spray gun to control the water-cement ratio, so that the concrete surface is smooth, moist and shiny, and there is no flow and dry spots. After 2 hours of final setting of shotcrete, spray water for 7 days. The number of water sprays per day should be sufficient to keep the shotcrete surface wet.

用于柔性桩的水泥采用普通硅酸盐水泥,标号为42.5,掺入量为15%,水灰比为1.0。水泥浆用水必须清洁、无污染,在注浆前30min左右开始制备水泥浆。在搅拌器中充分搅拌,搅拌均匀后从出浆口流出,经过滤网过滤,除去浆液中没有水化的颗粒和杂志。滤过的浆液进入泥浆泵,再泵送入注浆管。The cement used for the flexible pile is ordinary Portland cement, the grade is 42.5, the mixing amount is 15%, and the water-cement ratio is 1.0. The water used for cement slurry must be clean and pollution-free, and the cement slurry should be prepared about 30 minutes before grouting. Stir fully in the agitator, and then flow out from the slurry outlet after stirring evenly, and filter through a filter to remove unhydrated particles and impurities in the slurry. The filtered grout enters the mud pump and is pumped into the grouting pipe.

用于刚性桩的水泥采用普通硅酸盐水泥,标号为42.5,水灰比为0.45~0.5。细骨料选用级配合理、质地坚硬、颗粒纯净的天然中、粗砂;粗骨料选用坚硬的卵石或碎石,粒径为5mm~15mm。The cement used for the rigid pile is ordinary Portland cement, the grade is 42.5, and the water-cement ratio is 0.45-0.5. The fine aggregate is selected from natural medium and coarse sand with reasonable gradation, hard texture and pure particles; the coarse aggregate is selected from hard pebbles or crushed stones, with a particle size of 5mm to 15mm.

施工过程质量控制措施采用如下:The quality control measures in the construction process are as follows:

1钻机就位时必须平整稳固,垂直偏差不大于1%。1 When the drilling rig is in place, it must be flat and stable, and the vertical deviation should not exceed 1%.

2钢筋笼由主筋和横向箍筋组成,每隔2m左右设置加强筋。钢筋笼主筋保护层厚度不应小于35mm,主筋保护层允许偏差为10mm,钢筋笼主筋外侧加滑靴,以保证钢筋保护层。2 The reinforcement cage is composed of the main reinforcement and the transverse stirrup, and the reinforcement is set every 2m or so. The thickness of the protective layer of the main reinforcement of the steel cage should not be less than 35mm, and the allowable deviation of the protective layer of the main reinforcement is 10mm. Sliding shoes are added outside the main reinforcement of the steel cage to ensure the protective layer of the steel reinforcement.

3钢筋笼底部将6根主筋加长,内弯连接形成碗状,作为振动芯管与钢筋笼的连接,同时底部横向箍筋与主筋焊点加强。设置2个~4个起吊点,起吊点横向箍筋应做成双箍加强,避免出现吊放时开焊。3. At the bottom of the reinforcement cage, the six main reinforcements are lengthened and connected inwardly to form a bowl shape, which is used as the connection between the vibrating core tube and the reinforcement cage, and at the same time, the solder joints between the bottom horizontal stirrup and the main reinforcement are strengthened. Set 2 to 4 lifting points, and the horizontal stirrups at the lifting points should be strengthened with double hoops to avoid open welding when lifting.

4刚性桩混凝土浇筑后混凝土强度应满足设计要求,混凝土凝结良好,不得有蜂窝、空洞、离析、裂隙、夹层等不良现象,混凝土不得有脱粘露钢筋笼现象。4. After the rigid pile concrete is poured, the concrete strength should meet the design requirements. The concrete should set well without honeycombs, cavities, segregation, cracks, interlayers and other undesirable phenomena, and the concrete should not have debonding and exposed steel cages.

5刚性桩混凝土坍落度满足180mm~220mm,具有良好的和易性、粘结性和保水性,初凝时间以满足灌注时间为原则。5 The concrete slump of the rigid pile should meet 180mm-220mm, and it has good workability, cohesiveness and water retention, and the initial setting time should meet the pouring time as the principle.

本发明有显著的经济效益,传统方法是止水结构和挡土结构是分离的,通常采用柔性桩形成止水帷幕,而在柔性桩内侧设置刚性桩进行挡土,而本发明中刚性桩一方面可以挡土,又可以止水,刚性桩和柔性桩数量远远小于传统方法,具有明显的经济效益。本发明中刚性桩和柔性桩施工时不产生挤土效应,在施工时对地基基础几乎不产生任何附加应力,从而减少土体扰动,对周边环境影响很小。The present invention has significant economic benefits. The traditional method is that the water-stop structure and the soil-retaining structure are separated. Usually, flexible piles are used to form a water-stop curtain, and rigid piles are arranged inside the flexible piles to retain soil. In the present invention, the rigid piles are one On the one hand, it can retain soil and stop water. The number of rigid piles and flexible piles is far smaller than that of traditional methods, which has obvious economic benefits. In the present invention, the rigid pile and the flexible pile do not produce soil squeezing effect during construction, and almost no additional stress is generated on the foundation during construction, thereby reducing soil disturbance and having little impact on the surrounding environment.

本发明具有以下特点:施工质量容易得到保证,工程成本低。施工振动、噪声小,对周边环境影响小施工周期短,支护效果较好。本发明适用于浅层有碎石或卵石等硬夹层的软土地质情况下的基坑支护。The invention has the following characteristics: the construction quality is easily guaranteed, and the engineering cost is low. The construction vibration and noise are small, the impact on the surrounding environment is small, the construction period is short, and the support effect is good. The invention is suitable for foundation pit support under soft ground conditions with hard interlayers such as crushed stones or pebbles in the shallow layer.

附图说明Description of drawings

图1为工艺流程图,图2为刚性桩和柔性桩布置平面示意图。Fig. 1 is a process flow diagram, and Fig. 2 is a schematic plan view of the arrangement of rigid piles and flexible piles.

附图标记:1、刚性桩,2、柔性桩。Reference signs: 1, rigid pile, 2, flexible pile.

具体实施方式detailed description

以下结合附图对本实施例进行详细描述。The present embodiment will be described in detail below in conjunction with the accompanying drawings.

温州承丰大厦高度为33m,总建筑面积57880m2,采用框架剪力墙结构,该工程基坑开挖深度5.3m,基坑开挖面积约为5330m2,地质报告反映场地土在8m左右有厚度约0.8~1.5m的碎石夹层,基坑支护采取刚柔组合桩基坑支护施工方法。Wenzhou Chengfeng Building is 33m high, with a total construction area of 57,880m 2 . It adopts a frame shear wall structure. The foundation pit excavation depth of the project is 5.3m, and the excavation area of the foundation pit is about 5,330m 2 . The geological report shows that the site soil is about 8m. For the crushed stone interlayer with a thickness of about 0.8-1.5m, the foundation pit support adopts the construction method of rigid-flexible pile foundation pit support.

图1为工艺流程图,施工步骤包括:Figure 1 is a process flow chart, and the construction steps include:

1测量放线定位1. Measurement and setting-out positioning

清理施工场地后,应复测甲方提供的基点和基线,确定无误后,再根据基点和基线放出具体桩位,桩位测放顺序按施工顺序进行,桩位应固定好,桩中心线偏差小10mm,并做好测量记录,准确无误后方可施工。After cleaning the construction site, the base point and baseline provided by Party A should be retested. After confirming that they are correct, the specific pile positions should be released according to the base point and baseline. The minimum is 10mm, and the measurement record should be done well, and the construction can only be carried out after it is accurate.

2钻机就位2 rigs in place

钻机应保持平稳,确保施工中不发生任何倾斜移动。为准确控制钻孔深度,应在机架上设置控制标尺,以便观测。The drilling rig should be kept stable to ensure that no tilting movement occurs during construction. In order to accurately control the drilling depth, a control scale should be set on the frame for observation.

3钻机引孔3 drilling rig lead hole

桩垂直度达不到要求,桩下部止水帷幕会出现渗漏,达不到止水的效果。为了控制桩垂直度,采取如下措施:在钻机桩架的滑道上,设置两个具有定向作用的护筒,内径仅大于钻杆直径10mm,解决了钻杆的摩擦与摆动问题。在挺杆底部设置自制重力垂直度仪。桩位对中后,在挺杆底部垫枕木并压实,保证在挺杆受力摆动时,靠钻机绕轴自锁装置和挺杆与枕木产生的摩擦力抵抗摆动,使桩位不产生变化。在桩中心对位、钻杆调垂直度后,用经纬仪再检测钻杆垂直度,并在钻孔过程中随时监测,确保定位误差小于5mm,施工误差小于10mm。If the verticality of the pile does not meet the requirements, the water-stop curtain at the bottom of the pile will leak, and the water-stop effect will not be achieved. In order to control the verticality of the pile, the following measures are taken: on the slideway of the pile frame of the drilling rig, two casings with directional function are installed, and the inner diameter is only 10mm larger than the diameter of the drill pipe, which solves the problem of friction and swing of the drill pipe. Set up a self-made gravity verticality instrument at the bottom of the tappet. After the pile position is centered, put a sleeper on the bottom of the tappet and compact it to ensure that when the tappet swings under force, the self-locking device around the axis of the drilling rig and the friction generated by the tappet and the sleeper resist the swing, so that the pile position does not change. . After aligning the pile center and adjusting the verticality of the drill pipe, use theodolite to check the verticality of the drill pipe again, and monitor it at any time during the drilling process to ensure that the positioning error is less than 5mm and the construction error is less than 10mm.

4边钻进泵送水泥浆4 side drilling pumping cement slurry

钻到预定深度后,必须在孔底处进行空转清土,然后停止转动,边泵送水泥浆边提钻至地面,提钻时进行匀速转动,使泵送水泥浆和土均匀拌合,形成柔性桩。软土层钻进速度为0.8~1m/min,硬夹层部位钻进速度要放慢,钻进速度为0.2~0.4m/min,如果钻机出现摇晃现象则钻进速度还要放慢。After drilling to the predetermined depth, it must be idling at the bottom of the hole to clear the soil, then stop the rotation, lift the drill to the ground while pumping the cement slurry, and rotate at a constant speed when lifting the drill to make the pumped cement slurry and soil evenly mixed to form a Flexible pile. The drilling speed in the soft soil layer is 0.8-1m/min, and the drilling speed in the hard interlayer should be slowed down, and the drilling speed is 0.2-0.4m/min. If the drilling rig shakes, the drilling speed should be slowed down.

5压灌混凝土5 pressure poured concrete

柔性桩施工完毕后马上在刚性桩设计部位钻孔,钻到预定深度后,必须在孔底处进行空转清土,然后停止转动,边泵送混凝土边提钻至地面,提钻时不得转动,并保持匀速提升,确保钻头始终埋在混凝土中,防止断桩。由于刚性桩和柔性桩咬合部位可能会有一定的强度,钻进速度要放慢,软土层钻进速度为0.5~0.7m/min,硬夹层部位钻进速度还要放慢,钻进速度为0.1~0.3m/min,如果钻机出现摇晃现象则钻进速度再放慢。Immediately after the completion of the construction of the flexible pile, drill the hole at the design position of the rigid pile. After drilling to the predetermined depth, the soil must be idly cleared at the bottom of the hole, and then stop the rotation. Lift the drill to the ground while pumping the concrete. Do not rotate when lifting the drill. And keep lifting at a constant speed to ensure that the drill bit is always buried in the concrete to prevent the pile from breaking. Since the occlusal part of rigid pile and flexible pile may have certain strength, the drilling speed should be slowed down. It is 0.1~0.3m/min. If the drilling rig shakes, the drilling speed will be slowed down.

6插入钢筋笼6 Insert the reinforcement cage

浇筑混凝土后,通过振动装置将钢筋笼插入混凝土,形成刚性桩。刚性桩和柔性桩布置平面示意图如图2所示。振动装置采用中低频率振动锤,并安装了隔振装置;振动锤顶部有一个吊环,用于起吊振动装置和大刚度芯管;钢筋笼对正圈是用来固定和对正钢筋笼的;吊绳系于振动锤上,用于吊车起吊,同时用人来操纵确保钢筋笼安放的垂直度;振动锤下部及钢筋笼上焊有2个~4个钢环,穿入钢丝绳卡紧,起吊钢筋笼并定位。大刚度芯管用法兰盘连接在振动装置上,大刚度芯管下端压在钢筋笼末端,钢筋笼上端与振动装置柔性连接,大刚度芯管下端开口,中部、上部开通气孔。After the concrete is poured, the steel cage is inserted into the concrete by a vibrating device to form a rigid pile. The planar layout of rigid piles and flexible piles is shown in Figure 2. The vibrating device adopts a medium and low frequency vibrating hammer, and a vibration isolating device is installed; there is a lifting ring on the top of the vibrating hammer, which is used to lift the vibrating device and the high-rigidity core tube; the steel cage alignment ring is used to fix and align the steel cage; The sling is tied to the vibrating hammer and used for lifting by a crane. At the same time, people are used to operate it to ensure the verticality of the reinforcement cage; 2 to 4 steel rings are welded on the lower part of the vibrating hammer and the reinforcement cage, which are inserted into the wire rope and clamped to lift the reinforcement. Cage and position. The high-rigidity core tube is connected to the vibrating device with a flange, the lower end of the high-rigidity core tube is pressed against the end of the steel cage, the upper end of the steel cage is flexibly connected to the vibrating device, the lower end of the high-rigidity core tube is open, and air holes are opened in the middle and upper parts.

7做桩顶混凝土压顶梁7 Make pile top concrete pressure beam

桩顶混凝土压顶梁强度采用C25或者C30,桩顶混凝土压顶梁在锚杆部位设置预留孔,以便于钻机进行钻孔。The strength of the pile top concrete pressure beam is C25 or C30, and the pile top concrete pressure beam is provided with a reserved hole at the anchor rod to facilitate drilling by the drilling rig.

8锚杆施工8 Anchor construction

采用潜孔钻机根据设计倾角进行钻孔,孔距误差不大于150mm,孔深误差不大于50mm。钻孔完成后用灰浆泵向孔内灌注水泥浆,注浆压力为0.1~0.2MPa。注浆时注浆管应插入距孔底约100mm处,随水泥浆注入缓缓拔出,至钻孔饱满为止。然后将钢筋杆体插入注满水泥浆的钻孔中。The down-the-hole drilling rig is used to drill holes according to the design inclination, the error of the hole distance is not greater than 150mm, and the error of the hole depth is not greater than 50mm. After the drilling is completed, use a mortar pump to pour cement slurry into the hole, and the grouting pressure is 0.1-0.2MPa. When grouting, the grouting pipe should be inserted about 100mm from the bottom of the hole, and slowly pulled out with the grout injection until the borehole is full. The rebar body is then inserted into the drilled hole filled with grout.

9第一次喷射混凝土9 Shotcrete for the first time

埋设控制厚度标志的φ6短钢筋,用高压水冲洗边坡,湿润边坡表面。先将水泥、砂、碎石按配合比干拌均匀后再过筛装入喷射机,然后开始喷射第一层混凝土。喷射作业应分段分片、自上而下依次进行,喷射时喷头与受喷面应垂直,保持0.8m~1.0m的距离,喷射手持喷枪做均匀旋转运动,以保证喷射出的混凝土密实均匀。同时控制好水灰比,回弹率不应大于15%,喷射混凝土终凝2h后喷水养护。Bury short φ6 steel bars with thickness control marks, wash the slope with high-pressure water, and moisten the surface of the slope. First dry mix the cement, sand and gravel according to the mixing ratio, then sieve and load them into the spraying machine, and then start spraying the first layer of concrete. The spraying operation should be carried out in sections and pieces, from top to bottom. When spraying, the nozzle should be perpendicular to the surface to be sprayed, keeping a distance of 0.8m ~ 1.0m, and the hand-held spray gun should be rotated evenly to ensure that the sprayed concrete is dense and uniform. . At the same time, the water-cement ratio should be well controlled, the rebound rate should not be greater than 15%, and the sprayed concrete should be sprayed with water for curing after 2 hours of final setting.

10挂钢丝网10 hanging wire mesh

用细铁丝将经调直的φ6钢筋绑扎成钢筋网片,钢筋网的交叉点应绑扎结实。Bind the straightened φ6 steel bars into steel mesh sheets with thin iron wires, and the intersection points of the steel mesh should be tied firmly.

11第二次喷射混凝土11 Second shotcrete

用高压水将第一层喷射混凝土面冲洗干净并湿润表面。第二层混凝土喷射顺序和操作方法与第一层相同。开始喷射时应减小喷头与受喷面的距离,并调整喷射角度,以保证第二层喷射混凝土的密实性。喷射中若有被钢筋网架住出现混凝土脱落应及时清除。喷射人员应调整喷枪的供水阀门,控制水灰比,使混凝土表面平整,湿润光泽,无流淌干斑现象。喷射混凝土终凝2h后喷水养护7d。每天喷水的次数应能保持喷射混凝土表面湿润。Rinse off the first coat of shotcrete with high pressure water and wet the surface. The second layer of concrete spraying sequence and operation method is the same as the first layer. When starting to spray, the distance between the nozzle and the sprayed surface should be reduced, and the spray angle should be adjusted to ensure the compactness of the second layer of sprayed concrete. If the concrete falls off due to being supported by the steel mesh during spraying, it should be removed in time. Spraying personnel should adjust the water supply valve of the spray gun to control the water-cement ratio, so that the concrete surface is smooth, moist and shiny, and there is no flow and dry spots. After 2 hours of final setting of shotcrete, spray water for 7 days. The number of water sprays per day should be sufficient to keep the shotcrete surface wet.

施工过程中对基坑进行监测,监测结果表明基坑变形量在规定范围内,周围道路及地面未出现沉降现象,实施效果理想。During the construction process, the foundation pit was monitored, and the monitoring results showed that the deformation of the foundation pit was within the specified range, and the surrounding roads and ground did not appear to settle, and the implementation effect was ideal.

Claims (4)

1. press from both sides a hard formation Soft Clay rigid-flexible mechanical arm base pit stand construction, it is characterized in that utilizing convolution boring through hard interbedded layer, when getting into projected depth, by swirl vanes cutting weak soil, drilling rod is carried on rotary water jet mud limit, limit, thus forms flexible pile; Utilize convolution boring through hard interbedded layer, when getting into projected depth, pumped by concrete by swirl vanes by bottom drill bit, drilling rod is carried to ground in perfusion limit, limit, thus forms pump pressure plain concrete pile; To sling subsequently the vibrating device, large rigidity core pipe and the reinforcing cage that connect, reinforcing cage lower end is inserted in concrete pile body, rely on gravity and vibrating device to drive large rigidity core pipe to vibrate reinforcing cage lower end, make reinforcing cage sink down into projected depth, thus form rigid pile; First to construct flexible pile, rigid pile of then constructing, rigid pile and flexible pile snap-fit arrangement, form water-stop curtain, rigid pile not only plays the effect of sealing, also serves the effect of bank protection;
It is characterized in that construction sequence comprises:
(1) surveying setting-out location
Cleaning construction plant after, the basic point of answering repetition measurement Party A to provide and baseline, determine errorless after, release concrete stake position according to basic point and baseline again, measuring order in stake position is undertaken by sequence of construction, and stake position should fix, the little 10mm of pile center's line deviation, and carry out surveying record, can construct after accurate;
(2) driller insertion
Held stationary answered by rig, guarantees, in construction, any inclination movement does not occur; For the accurate keyhole degree of depth, should control scale be set in frame, to observe;
(3) rig draws hole
(4) pumps water mud is crept on limit
After getting into desired depth, must carry out dallying in bottom, hole soil clearly, and then stop operating, pumps water mud limit, limit is carried and is drilled into ground, carries out uniform rotation when carrying brill, makes pumps water mud and the even mix of soil, forms flexible pile; Soft Soil Layer rate of penetration is 0.8 ~ 1m/min, and hard interbedded layer position rate of penetration will slow down, and rate of penetration is 0.2 ~ 0.4m/min, if swag phenomenon appears in rig, rate of penetration also will slow down;
(5) guncreting
At once in rigid pile design position boring after flexible pile construction, after getting into desired depth, must carry out dallying in bottom, hole soil clearly, then stop operating, pumping of concrete limit, limit is carried and is drilled into ground, must not rotate when carrying brill, and the lifting that remains a constant speed, guarantee that drill bit is embedded in concrete all the time, prevent broken pile; Because may there be certain intensity at rigid pile and flexible pile occlusion position, rate of penetration will slow down, and Soft Soil Layer rate of penetration is 0.5 ~ 0.7m/min, and hard interbedded layer position rate of penetration also will slow down, rate of penetration is 0.1 ~ 0.3m/min, if swag phenomenon appears in rig, rate of penetration slows down again;
(6) reinforcing cage is inserted
After concreting, by vibrating device, reinforcing cage is inserted concrete, form rigid pile;
(7) stake top concrete capping beam is done
Stake top concrete capping beam intensity adopts C25 or C30, and stake top concrete capping beam arranges preformed hole at anchor pole position, so that rig is holed;
(8) anchor bolt construction
Adopt down-the-hole drill to hole according to design inclination angle, pitch-row error is not more than 150mm, and hole depth error is not more than 50mm; Holed rear mortar pump to grout injection in hole, and grouting pressure is 0.1 ~ 0.2MPa; During slip casting, Grouting Pipe should be inserted apart from being about 100mm place at the bottom of hole, slowly extracts with cement paste injection, to hole full; Then being inserted by the reinforcing bar body of rod fills in the boring of cement paste;
(9) first time sprayed mortar
Bury φ 6 bar dowel controlling thickness mark underground, use high pressure water washing side slope, moistening side slope surface; First cement, sand, rubble are loaded spraying machine by after match ratio dry mixing evenly after sieve, then start to spray first floor concrete; Spraying operation is answered segmentation and slicing, is carried out successively from top to bottom, during injection shower nozzle with should be vertical by spray plane, keep the distance of 0.8m ~ 1.0m, spray pistol and do Rotating with Uniform motion, even to ensure the concrete compaction ejected; Control water/binder ratio well, rebound degree should not be greater than 15%, wet curing after sprayed mortar final set 2h simultaneously;
(10) gauze wire cloth is hung
With thin wire, φ 6 reinforcing bar binding through straightening is become reinforced mesh, the crosspoint of steel mesh reinforcement answers colligation solid;
(11) second time sprayed mortar
With water under high pressure, first floor sprayed mortar face is rinsed well and wetted surface; Second layer concrete ejection order is identical with first floor with method of operating; Shower nozzle and the distance by spray plane should be reduced when starting to spray, and adjust spray angle, to ensure the density of second layer sprayed mortar; Firmly occurred that concrete comes off if having in injection by bar frame should remove in time; Injection personnel should adjust the water supply valve of spray gun, control water/binder ratio, make concrete surface smooth, moistening gloss, without trickling dry spot phenomenon.
2. folder hard formation Soft Clay rigid-flexible mechanical arm base pit stand construction according to claim 1, it is characterized in that on the slideway of rig pile frame, arrange the casing that two have orientation, internal diameter is only greater than drill pipe diameter 10mm, solves friction and the vibration problems of drilling rod; Self-control gravity Verticality gauge is set bottom tappet; After stake position centering, bolster wood bottom tappet compacting, ensure when the stressed swing of tappet, to resist and swing, stake position is not changed by rig around the frictional force that axle self-locking device and tappet and sleeper produce; After pile center's contraposition, drilling rod Uprightness adjusting degree, detect drilling rod verticality again with transit, and monitor at any time in boring procedure, guarantee that position error is less than 5mm, construction error is less than 10mm.
3. folder hard formation Soft Clay rigid-flexible mechanical arm base pit stand construction according to claim 1, is characterized in that vibrating device adopts low and medium frequency vibrating hammer, and has installed isolation mounting; Suspension ring are arranged at vibrating hammer top, for lifting by crane vibrating device and large rigidity core pipe; Reinforcing cage aligns circle and is used to fixing and aligns reinforcing cage; Lifting rope lies on vibrating hammer, and for crane lifting, the verticality guaranteeing that reinforcing cage is laid is handled in employment simultaneously; Vibrating hammer bottom and reinforcing cage are welded with 2 ~ 4 steel loops, penetrate wire rope clamping, lifting reinforcing cage is also located; The effective flange of large rigidity core is connected on vibrating device, and large rigidity core pipe lower end is pressed in reinforcing cage end, and reinforcing cage upper end and vibrating device flexibly connect, and large rigidity core pipe lower ending opening, pore is opened at middle part, top.
4. folder hard formation Soft Clay rigid-flexible mechanical arm base pit stand construction according to claim 1, is characterized in that wet curing 7d after sprayed mortar final set 2h; Every day, the number of times of water spray should be able to keep sprayed mortar surface wettability.
CN201410164052.2A 2014-04-14 2014-04-14 Rigid-flexible combined pile foundation pit supporting construction method for hard-layer soft soil geology Expired - Fee Related CN103938637B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201410164052.2A CN103938637B (en) 2014-04-14 2014-04-14 Rigid-flexible combined pile foundation pit supporting construction method for hard-layer soft soil geology

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201410164052.2A CN103938637B (en) 2014-04-14 2014-04-14 Rigid-flexible combined pile foundation pit supporting construction method for hard-layer soft soil geology

Publications (2)

Publication Number Publication Date
CN103938637A CN103938637A (en) 2014-07-23
CN103938637B true CN103938637B (en) 2016-04-06

Family

ID=51186492

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201410164052.2A Expired - Fee Related CN103938637B (en) 2014-04-14 2014-04-14 Rigid-flexible combined pile foundation pit supporting construction method for hard-layer soft soil geology

Country Status (1)

Country Link
CN (1) CN103938637B (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104264688B (en) * 2014-10-22 2016-06-08 广州市城市规划勘测设计研究院 Manually digging hole non-uniform pile support construction process
CN105887890A (en) * 2016-04-14 2016-08-24 广州市鲁班建筑集团股份有限公司 Plastic pile, construction method of plastic pile and foundation pit supporting watertight seal structure
CN106761814A (en) * 2017-02-08 2017-05-31 海南大学 A kind of pipe curtain and bamboo reinforcement grouted anchor bar combined retaining structure and method
CN107587502B (en) * 2017-09-23 2020-10-23 北京建材地质工程有限公司 Construction method for rotary drilling hole-forming pressure-grouting cement soil occlusion curtain pile
CN110080238A (en) * 2018-12-07 2019-08-02 深圳市工勘岩土集团有限公司 Deep one meat or fish dyadic combined type pile forming method of loose Backfilled Stone Layer interlocking pile
CN112323773A (en) * 2020-11-26 2021-02-05 中国铁路设计集团有限公司 Rigid-flexible composite uplift pile and installation method thereof

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101328712A (en) * 2008-07-29 2008-12-24 上海市第二建筑有限公司 Construction method of interlocking pile for soft soil and soil layer with obstacle
CN202194127U (en) * 2011-05-31 2012-04-18 中国石油化工集团公司 Reducing high-pressure jet grouting rigid pile
CN202194148U (en) * 2011-07-15 2012-04-18 深圳市鸿荣轩建设工程有限公司 Waterproof curtain
CN202626978U (en) * 2012-04-10 2012-12-26 中冶建筑研究总院有限公司 Cemented soil secant pile group, diaphragm wall constituted by same and building foundation pit support system constituted by cemented soil secant pile group

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101159755B1 (en) * 2008-08-29 2012-06-28 주식회사 이엔지건설엔지니어링 Finishing block and Retaining wall using the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101328712A (en) * 2008-07-29 2008-12-24 上海市第二建筑有限公司 Construction method of interlocking pile for soft soil and soil layer with obstacle
CN202194127U (en) * 2011-05-31 2012-04-18 中国石油化工集团公司 Reducing high-pressure jet grouting rigid pile
CN202194148U (en) * 2011-07-15 2012-04-18 深圳市鸿荣轩建设工程有限公司 Waterproof curtain
CN202626978U (en) * 2012-04-10 2012-12-26 中冶建筑研究总院有限公司 Cemented soil secant pile group, diaphragm wall constituted by same and building foundation pit support system constituted by cemented soil secant pile group

Also Published As

Publication number Publication date
CN103938637A (en) 2014-07-23

Similar Documents

Publication Publication Date Title
CN103938637B (en) Rigid-flexible combined pile foundation pit supporting construction method for hard-layer soft soil geology
CN100572683C (en) The large-diameter ultra-deep rock borehole bottom-expanding filling pile job practices
CN104631470B (en) The large particle diameter sand gravel of high water level geology deep basal pit combination supporting construction method
CN105201513A (en) Shaft construction method for rail transit
CN102926398B (en) A kind of for Salt Lake Area iron tower of power transmission line bolts of inclined column type anti-corrosion foundation construction method
CN107447765A (en) Side slope construction supported with framed anchor construction
CN108517877B (en) Supporting construction method combining consolidation grouting of hybrid filling ultra-deep foundation pit with double-row steel pipe piles
CN107524142A (en) A kind of holing with slurry wall protection cast-in-place pile construction method
CN106759297A (en) A kind of construction method of support pile and three pipe high-pressure rotary jet grouting pile deep basal pits
CN107542108A (en) A kind of reverse construction method of building basement structure
CN101429766A (en) Ground strengthened high pressure rotary spraying pile construction technique
CN105155550A (en) Construction method for digging deep foundation pit in large-thickness highly weathered sandstone stratum in combined supporting mode
CN102146672A (en) Method for constructing pile foundation in karst area
CN104831734A (en) Construction method of jet-grouting pile and composite soil-nailed wall support for deep foundation pit construction
CN113293773A (en) Foundation pit supporting system and construction method thereof
CN112144559B (en) Well construction method in high-water-rich loess sand pebble stratum pressure-variable pipe well
CN107100164A (en) A kind of long auger guncreting pile construction method
CN109706952A (en) Large-scale well-sinking construction method
CN211713954U (en) Cast-in-situ bored pile in deep fine sand stratum
CN102235007B (en) Method for supporting deep foundation with upper nail-lower pile combination
CN104988981B (en) A kind of well construction method of riding on present situation operation shield method drainage pipeline
CN214883611U (en) Bearing pile or uplift pile with multiple main ribs
CN206971247U (en) Concrete toe board foundation reinforcing structure arranged on unloading rock mass
CN110258600A (en) A kind of vertical cofferdam construction engineering method suitable for deep water waters
CN113175350B (en) A construction method for wastewater pumping station in water-rich sand layer

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
CB03 Change of inventor or designer information

Inventor after: Yu Donghua

Inventor before: Zhu Kui

CB03 Change of inventor or designer information
TR01 Transfer of patent right

Effective date of registration: 20170401

Address after: 523112 Dongcheng District Province, Dongguan, Dongguan Road, long road, No. silver Gate Street, room 3, No. 202

Patentee after: Guangdong Keyi Xintai building science and Technology Development Co Ltd

Address before: 325000 Jinchuan economic and Technological Development Zone, Tianhe Road, Wenzhou, No. 4 Zhejiang Road

Patentee before: Ye Changqing

TR01 Transfer of patent right
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20160406

Termination date: 20210414

CF01 Termination of patent right due to non-payment of annual fee