CN111622216A - Construction method of pile foundation joist weighing type retaining wall - Google Patents
Construction method of pile foundation joist weighing type retaining wall Download PDFInfo
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- CN111622216A CN111622216A CN202010505267.1A CN202010505267A CN111622216A CN 111622216 A CN111622216 A CN 111622216A CN 202010505267 A CN202010505267 A CN 202010505267A CN 111622216 A CN111622216 A CN 111622216A
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- 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
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/02—Retaining or protecting walls
- E02D29/0258—Retaining or protecting walls characterised by constructional features
- E02D29/0275—Retaining or protecting walls characterised by constructional features cast in situ
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
- E02D3/02—Improving by compacting
- E02D3/10—Improving by compacting by watering, draining, de-aerating or blasting, e.g. by installing sand or wick drains
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
- E02D3/02—Improving by compacting
- E02D3/10—Improving by compacting by watering, draining, de-aerating or blasting, e.g. by installing sand or wick drains
- E02D3/103—Improving by compacting by watering, draining, de-aerating or blasting, e.g. by installing sand or wick drains by installing wick drains or sand bags
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D9/00—Removing sheet piles bulkheads, piles, mould-pipes or other moulds or parts thereof
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- 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
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Abstract
The invention relates to a construction method of a pile foundation joist constant weight type retaining wall, and belongs to the technical field of pile foundation joist constant weight type retaining wall construction. The pile hole is constructed by adopting a rotary drilling wet drilling process, so that quality accidents such as hole collapse, hole shrinkage and the like are avoided; when the reinforcement cage is hoisted, two-point hoisting is adopted, so that the deformation of the reinforcement cage can be effectively prevented; after the guide pipe is installed, the guide pipe is utilized to clean the hole again, and the later-stage pouring quality can be effectively guaranteed. In the construction of the joist, the pile head circular cutting construction process is utilized, the integral connection of the pile foundation and the joist can be conveniently realized, and the top steel bar of the pile foundation is inserted into the joist. In the construction of the balance weight type retaining wall, a triple filtering structure is formed by the crushed stone layer, the sand filtering layer and the geotechnical filter cloth, so that piping and soil flowing can be effectively prevented; in addition, the soft water permeable pipes arranged along the length direction of the balance weight type retaining wall form a longitudinal drainage structure, and the drainage effect is further improved.
Description
Technical Field
The invention relates to a construction method of a pile foundation joist constant weight type retaining wall, and belongs to the technical field of pile foundation joist constant weight type retaining wall construction.
Background
The pile foundation joist constant weight retaining wall has low requirement on the bearing capacity of the foundation, good slope collecting effect and wide application in slope roadbeds. From top to bottom, pile foundation joist weighing type retaining wall includes pile foundation, joist, weighing type retaining wall three part in proper order, wholly all adopts reinforced concrete structure. The situation that the drilling depth is deep often exists during construction, the construction difficulty is high, and once the construction control is improper, quality accidents such as hole collapse and hole shrinkage are easily caused. Because the pile hole is darker, correspondingly, the length of steel reinforcement cage is also just longer, and the installation degree of difficulty is also great, though steel reinforcement cage adds the good straightness that hangs down of strict control when man-hour on ground platform, if steel reinforcement cage reinforcement measure is improper, bending deformation when the transportation is in process or lifts by crane very easily to cause and to be difficult to put into the hole, even cause the pore wall to collapse. In addition, in order to effectively reduce the water seepage pressure on the back of the balance weight retaining wall, a plurality of water drain pipes are required to be arranged on the balance weight retaining wall, and the water seepage on the back of the balance weight retaining wall is discharged outside. The most common drainage configurations currently used are as follows: the water drain pipe adopts a PVC pipe, the gravel pile is arranged on the back of the balance weight type retaining wall to serve as a filter layer, and water is directly discharged outside through the PVC pipe. This drainage structure has the following disadvantages: the filter layer has a simple structure, and piping and soil flow are easy to occur; the longitudinal drainage structure is lacked, and the drainage effect is not good.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the construction method of the pile foundation joist weighing type retaining wall is convenient to construct and can effectively guarantee construction quality.
In order to solve the technical problems, the invention adopts the technical scheme that: the construction method of the pile foundation joist constant weight type retaining wall sequentially comprises the following steps of pile foundation construction, joist construction and constant weight type retaining wall construction; the pile foundation construction comprises the following steps:
leveling the field, and building a pile foundation construction platform;
embedding a pile casing;
drilling construction is carried out by adopting a rotary drilling rig, and the wall is protected by mud; in the drilling process, the lost and leaked slurry is replenished in time, so that the liquid level of the slurry is 1.0-1.5 m higher than the water level outside the hole or the underground water level;
when the drilling depth reaches the design requirement, checking the hole depth, the hole diameter and the hole shape, and cleaning the hole after confirming that the design requirement is met;
after hole cleaning is finished, installing a reinforcement cage; when the reinforcement cage is hoisted, two-point hoisting is adopted, wherein a first hoisting point is arranged at the top end of the reinforcement cage, a second hoisting point is arranged at the side edge of the reinforcement cage, the position which is apart from the bottom end of the reinforcement cage by the length 1/3 of the reinforcement cage is taken as a positioning mark point, and the second hoisting point is positioned between the positioning mark point and the middle point of the reinforcement cage in the length direction; when in lifting, the first lifting point is lifted firstly to slightly lift the steel reinforcement cage, then the steel reinforcement cage is lifted simultaneously with the second lifting point, the second lifting point is slowly loosened along with the continuous rising of the steel reinforcement cage until the steel reinforcement cage is vertical to the ground or a platform, the lifting of the second lifting point is stopped, the steel reinforcement cage is lifted to be right above the pile hole by the first lifting point, and then the steel reinforcement cage is lifted and placed into the pile hole; the upper end of the reinforcement cage is positioned and fixed at the orifice;
installing a guide pipe, cleaning the hole by using the guide pipe, continuously pumping fresh slurry into the bottom of the hole by using a slurry pump through the guide pipe, and replacing sediments at the bottom of the hole;
and after hole cleaning is finished, pouring concrete by using the guide pipe.
Further, the method comprises the following steps: the steel reinforcement cage structure in the pile foundation construction is as follows: the reinforcement cage comprises a plurality of vertical main reinforcements parallel to the axis of the reinforcement cage, the vertical main reinforcements are distributed at intervals along the circumferential direction of the reinforcement cage, spiral stirrups are arranged outside a cylindrical structure surrounded by the vertical main reinforcements, the spiral stirrups are spirally distributed by taking the axis of the reinforcement cage as a central axis, the spiral stirrups are fixedly connected with the vertical main reinforcements, reinforcing stirrups are arranged in a cylindrical inner cavity surrounded by the vertical main reinforcements, the reinforcing stirrups are annular, a plurality of reinforcing stirrups are arranged at intervals along the length direction of the vertical main reinforcements, and the reinforcing stirrups and the vertical main reinforcements are welded and fixed; the inner ring of the reinforcement stirrup is provided with a cross reinforcing rib, and the cross reinforcing rib is fixedly connected with the reinforcement stirrup in a spot welding manner;
when a reinforcement cage is manufactured, reinforcement stirrups and cross reinforcing ribs are processed into an integral structure in advance, the reinforcement stirrups are placed according to a set interval, connecting positions of vertical main reinforcements are marked on the reinforcement stirrups at equal intervals, 6-8 vertical main reinforcements are welded on the reinforcement stirrups one by one in sequence to form a reinforcement framework, other vertical main reinforcements are uniformly welded on the reinforcement framework to form the whole framework, and finally spiral stirrups are bound or fixed on the reinforcement framework in a spot welding mode according to the interval of a design drawing to manufacture the reinforcement cage;
when the steel reinforcement cage hangs the inlet hole, the cross strengthening rib progressively demolishs through the cutting mode at the transfer in-process of steel reinforcement cage, demolishs the cross strengthening rib of first layer after, transfers the steel reinforcement cage to setting for the height, then demolishs the cross strengthening rib on second floor, so reciprocal, hangs the inlet hole until the steel reinforcement cage.
Further, the method comprises the following steps: in the structure of the steel reinforcement cage, positioning steel bars are arranged outside a cylindrical structure surrounded by vertical main bars, two ends of each positioning steel bar are connecting sections for fixedly connecting the vertical main bars, and the connecting sections are parallel to the vertical main bars and are welded and fixed with the vertical main bars; the middle part of the positioning steel bar is bent to form a positioning bulge which is arranged in a protruding way relative to the steel bar cage, the top of the positioning bulge is a straight line section which is parallel to the vertical main steel bar, and two sides of the straight line section are connected with the connecting section through inclined line sections; a plurality of groups of positioning steel bars are arranged at intervals along the length direction of the steel bar cage, and each group of positioning steel bars is at least three positioning steel bars arranged at intervals along the circumferential direction of the steel bar cage; the tops of the positioning bulges of the multiple groups of positioning reinforcing steel bars are all positioned on the same cylindrical surface, and the cylindrical surface and the reinforcing cage are arranged coaxially; the bottom ends of the vertical main ribs are all bent inwards to form inclined sections, and the inclined sections and the vertical extension lines of the bottom ends of the vertical main ribs form included angles of 4-6 degrees.
Further, the method comprises the following steps: in pile foundation construction, when concrete is poured, a measuring hammer is used for measuring the position of a concrete surface, and a guide pipe is lifted in time, so that the length of the concrete embedded in the guide pipe is controlled within the range of 2-6 m; the elevation of the top surface of the concrete pouring is controlled to be 0.5-1.5 m higher than the designed elevation of the pile top.
Further, the method comprises the following steps: the joist construction method comprises the following steps:
after pile foundation construction is completed, excavating a foundation pit and protecting;
marking a cutting line of the pile head by using paint according to the pile head elevation position of the pile foundation concrete, and cutting 2-4 cm deep cutting marks along the cutting line by using a cutting machine by an operator;
chiseling off the pile head above the cutting line by using an air compressor; when the pile head is chiseled off, the reinforcing steel bars are stripped one by one from outside to inside, the reinforcing steel bars cannot be damaged, after the pile head is completely stripped off, the pile head is chiseled off from the cutting mark, the chiseled-off pile head is vertically adjusted and transported away, then the rest pile foundation head is chiseled off manually, and the surrounding laitance is removed;
and (4) detecting the pile by adopting ultrasonic after the pile head is broken, and constructing the concrete of the joist part after the detection is qualified.
Further, the method comprises the following steps: the construction of the balance weight type retaining wall comprises the following steps:
after the joist construction is finished, erecting a scaffold, erecting a wall formwork and installing a water drain pipe; pouring wall concrete, removing the formwork and curing the concrete; backfilling the wall back;
when the wall back is backfilled, a sand filtering layer and a gravel layer are sequentially formed on the back of the weighing type retaining wall, and the sand filtering layer is arranged between the back of the weighing type retaining wall and the gravel layer; the water inlet end of the water drain pipe is positioned in the sand filter layer, and the water inlet end of the water drain pipe is wrapped with geotechnical filter cloth.
Further, the method comprises the following steps: in the construction of weighing type barricade, the outlet pipe is arranged for the layering, is provided with the soft pipe of permeating water in the outlet pipe of lowest floor corresponding position, and the soft pipe of permeating water is pre-buried in the sand filtration layer, and the soft pipe of permeating water is arranged along the length direction of weighing type retaining wall, and the soft pipe of permeating water passes through outer drainage system of pipeline intercommunication or directly is connected with the outlet pipe.
Further, the method comprises the following steps: in the construction of the constant weight retaining wall, the water inlet end position of the water drain pipe at the lowest layer is higher than the position of the side slope rock-soil interface at the back of the constant weight retaining wall, a geomembrane is arranged on the side slope rock-soil interface at the back of the constant weight retaining wall, and a sand filter layer and a gravel layer are arranged on the geomembrane.
The invention has the beneficial effects that: constructing a pile hole by adopting a rotary drilling wet drilling process, and replenishing lost and leaked slurry in time in the drilling process to ensure that the liquid level of the slurry is 1.0-1.5 m higher than the water level outside the hole or the underground water level so as to avoid quality accidents such as hole collapse, hole shrinkage and the like; when the reinforcement cage is hoisted, two-point hoisting is adopted, so that the deformation of the reinforcement cage can be effectively prevented; after the guide pipe is installed, the guide pipe is utilized to clean the hole again, and the later-stage pouring quality can be effectively guaranteed. In addition, the reinforcing stirrup and the cross reinforcing rib are additionally arranged inside the reinforcement cage, so that the deformation resistance of the reinforcement cage can be effectively improved, and meanwhile, the reinforcing structure is arranged inside the reinforcement cage, so that the fixed connection of the external spiral stirrup cannot be influenced, and the installation and the implementation are more convenient; the periphery at the steel reinforcement cage is provided with the spacer bar, and the bottom is provided with bending structure, can be favorable to the accuracy of steel reinforcement cage to transfer perpendicularly. In the construction of the joist, the pile head circular cutting construction process is utilized, the integral connection of the pile foundation and the joist can be conveniently realized, and the top steel bar of the pile foundation is inserted into the joist. In the construction of the balance weight type retaining wall, a triple filtering structure is formed by the crushed stone layer, the sand filtering layer and the geotechnical filter cloth, so that piping and soil flowing can be effectively prevented; in addition, the soft water permeable pipes arranged along the length direction of the balance weight type retaining wall form a longitudinal drainage structure, and the drainage effect is further improved.
Drawings
FIG. 1 is a process flow diagram of the practice of the present invention.
Fig. 2 is a schematic elevation structure view of the pile foundation of the present invention during construction.
Fig. 3 is a schematic view a-a of fig. 2.
Fig. 4 is a schematic view B-B of fig. 2.
Fig. 5 is a large drawing of the positioning steel bar in the pile foundation reinforcement cage of the invention.
Fig. 6 is a schematic view of a bottom end bending structure of a vertical main rib in the pile foundation reinforcement cage.
Fig. 7 is a schematic elevation view of the drainage structure of the present invention.
The labels in the figure are: 1-vertical main reinforcement, 11-first reinforcement, 12-second reinforcement, 2-spiral stirrup, 3-reinforcing stirrup, 4-cross reinforcing rib, 5-positioning reinforcement, 51-connecting section, 52-diagonal section, 53-straight section, 6-pile hole, 100-sand filter layer, 200-gravel layer, 300-soft permeable pipe and 400-original terrain line.
Detailed Description
The invention is further explained below with reference to the drawings and examples.
The construction method sequentially comprises the following steps of pile foundation construction, joist construction and constant weight retaining wall construction.
Referring to fig. 1, the pile foundation construction includes the following steps:
leveling the field, and building a pile foundation construction platform;
embedding a pile casing;
drilling construction is carried out by adopting a rotary drilling rig, and the wall is protected by mud; in the drilling process, loss and leakage mud is supplemented in time, so that the liquid level of the mud is 1.0-1.5 m higher than the water level outside the hole or the underground water level, and quality accidents such as hole collapse, hole shrinkage and the like are avoided;
when the drilling depth reaches the design requirement, checking the hole depth, the hole diameter and the hole shape, and cleaning the hole after confirming that the design requirement is met;
after hole cleaning is finished, installing a reinforcement cage; in order to prevent the deformation of the reinforcement cage, two-point hoisting is adopted when the reinforcement cage is hoisted, a first hoisting point is arranged at the top end of the reinforcement cage, a second hoisting point is arranged at the side edge of the reinforcement cage, the position which is apart from the bottom end of the reinforcement cage by the length 1/3 of the reinforcement cage is taken as a positioning mark point, and the second hoisting point is positioned between the positioning mark point and the middle point of the reinforcement cage in the length direction; when in lifting, the first lifting point is lifted firstly to slightly lift the steel reinforcement cage, then the steel reinforcement cage is lifted simultaneously with the second lifting point, the second lifting point is slowly loosened along with the continuous rising of the steel reinforcement cage until the steel reinforcement cage is vertical to the ground or a platform, the lifting of the second lifting point is stopped, the steel reinforcement cage is lifted to be right above the pile hole by the first lifting point, and then the steel reinforcement cage is lifted and placed into the pile hole; the upper end of the reinforcement cage is positioned and fixed at the orifice;
installing a guide pipe, cleaning the hole by using the guide pipe, continuously pumping fresh slurry into the bottom of the hole by using a slurry pump through the guide pipe, and replacing sediments at the bottom of the hole; and after hole cleaning is finished, pouring concrete by using the guide pipe. Because the steel reinforcement cage and the guide pipe are arranged for pouring underwater concrete, the gap in the period is long, and new slag is generated at the bottom of the hole, the guide pipe is used for secondary hole cleaning after the steel reinforcement cage and the guide pipe are arranged in sequence, and the pile forming quality can be effectively ensured.
When concrete is poured, the position of the concrete surface can be continuously measured by using a measuring hammer, and the guide pipe is lifted in time, so that the length of the concrete embedded in the guide pipe is controlled within the range of 2-6 m, and the lifting difficulty caused by the lifting or overlong embedding of the guide pipe is prevented; the elevation of the top surface of the concrete pouring is controlled to be 0.5 m-1.5 m higher than the designed elevation of the pile top, so that the floating slurry is removed, the measurement error is eliminated, and the pile forming quality is ensured.
As shown in fig. 2 to 6, the reinforcement cage structure in pile foundation construction of the present invention is as follows: including many vertical main muscle 1 that parallel with the steel reinforcement cage axis, vertical main muscle 1 is provided with spiral stirrup 2 along the circumference to interval distribution of steel reinforcement cage, the cylindrical structure outside that vertical main muscle 1 encloses, and spiral stirrup 2 uses the steel reinforcement cage axis to be the spiral distribution as the central axis, spiral stirrup 2 and 1 fixed connection of vertical main muscle, its characterized in that: a plurality of reinforcing stirrups 3 are arranged at intervals along the length direction of the vertical main reinforcement 1, and the reinforcing stirrups 3 are welded and fixed with the vertical main reinforcement 1; the inner ring of the reinforcement stirrup 3 is provided with a cross reinforcing rib 4, and the cross reinforcing rib 4 is fixedly connected with the reinforcement stirrup 3 in a spot welding manner.
When preparation steel reinforcement cage, add reinforcement stirrup 3 and cross strengthening rib 4 and process into overall structure in advance, then put reinforcement stirrup 3 according to setting for the interval, equidistant mark out vertical main reinforcement 1's hookup location on reinforcement stirrup 3, earlier weld 6 ~ 8 vertical main reinforcement 1 on enhancement stirrup 3 one by one in proper order, form steel reinforcement skeleton, later with 1 evenly weld other vertical main reinforcement to steel reinforcement skeleton on, form whole skeleton, fix spiral stirrup 2 on steel reinforcement skeleton according to design drawing interval ligature or spot welding, make steel reinforcement cage.
When the steel reinforcement cage hangs and puts the hole, cross strengthening rib 4 progressively demolishs through the cutting mode at the transfer in-process of steel reinforcement cage, demolishs the cross strengthening rib 4 back of first layer, transfers the steel reinforcement cage to setting for the height, then demolishs the cross strengthening rib 4 on second floor, so reciprocal, put the hole until the steel reinforcement cage hangs.
According to the invention, the reinforcing stirrup 3 and the cross reinforcing rib 4 are additionally arranged inside the reinforcement cage, so that the deformation resistance of the reinforcement cage can be effectively improved, and the deformation of the reinforcement cage in the transportation and lifting processes is avoided.
In addition, for effectively guaranteeing steel reinforcement cage's wholeness ability, vertical main muscle 1 is along steel reinforcement cage's circumference to even interval distribution, and the reinforcement stirrup 3 sets up along vertical main muscle 1's length direction even interval (in this embodiment, 3 every interval 2m of reinforcement stirrup set up one).
In order to facilitate smooth and accurate lowering of a reinforcement cage, positioning steel bars 5 are arranged on the outer side of a cylindrical structure enclosed by vertical main reinforcements 1, two ends of each positioning steel bar 5 are connecting sections 51 for fixedly connecting the vertical main reinforcements 1, and the connecting sections 51 are parallel to the vertical main reinforcements 1 and are welded and fixed with the vertical main reinforcements 1; the middle part of the positioning steel bar 5 is bent to form a positioning bulge which is arranged in a convex way relative to the steel bar cage, the top part of the positioning bulge is a straight line section 53 which is parallel to the vertical main bar 1, and two sides of the straight line section 53 are connected with the connecting section 51 through inclined line sections 52; a plurality of groups of positioning steel bars 5 are arranged at intervals along the length direction of the steel bar cage, and each group of positioning steel bars 5 is at least three positioning steel bars arranged at intervals along the circumferential direction of the steel bar cage; the tops of the positioning protrusions of the multiple groups of positioning steel bars 5 are all located on the same cylindrical surface, and the cylindrical surface and the steel reinforcement cage are coaxially arranged. The preferred form of arranging is, and every reinforcement stirrup 3's the position of arranging corresponds and sets up a set of spacer bar 5, and spacer bar 5 uses the plane at reinforcement stirrup 3 place to be the mirror symmetry arrangement as the center, and every group spacer bar 5 is for four along the even interval setting of steel reinforcement cage circumference. In the embodiment, the diameter of the pile hole 6 is designed to be 150cm, and under the condition of not considering the positioning steel bar 5, the single-side clearance between the outer side of the steel bar cage and the wall of the pile hole 6 is designed to be 5 cm; referring to fig. 4, the positioning reinforcing steel bar 5 is formed by bending a reinforcing steel bar with a diameter of 20mm and a length of 60cm, the length of the connecting section 51 on one side is 15cm, the length of the inclined line section 52 on one side is 10cm, the length of the straight line section 53 is 10cm, and the distance between the straight line section 53 and the axis of the connecting section 51 is about 4.9cm, namely the height of the protrusion is about 4.9 cm; the diameter of the spiral stirrup 2 is also 20mm, so that the outer side of the connecting section of the positioning steel bar 5 is flush with the outer side of the spiral stirrup 2, and the unilateral clearance between the positioning steel bar 5 and the wall of the pile hole 6 is about 0.1cm (calculated according to the formula 5cm-4.9 cm-0.1 cm). Adopt this structural style, the straightway 53 of spacer bar 5 forms less clearance (about 0.1cm) with 6 walls in stake hole, simultaneously with the help of the guide effect of the slash section 52 of spacer bar 5, can realize that the steel reinforcement cage is transferred perpendicularly smoothly.
In order to facilitate smooth and accurate lowering of the reinforcement cage, the bottom end of the vertical main reinforcement 1 is bent inwards to form an inclined section, the inclined section and the vertical extension line of the bottom end of the vertical main reinforcement 1 form an included angle of 4 degrees to 6 degrees, referring to fig. 6, the value of the included angle is marked as b in fig. 6, and the included angle is designed to be 5 degrees in the embodiment.
Referring to fig. 1, joist construction includes the following steps:
after pile foundation construction is completed, excavating a foundation pit and protecting;
marking a cutting line of the pile head by using paint according to the pile head elevation position of the pile foundation concrete, and cutting 2-4 cm deep cutting marks along the cutting line by using a cutting machine by an operator;
chiseling off the pile head above the cutting line by using an air compressor; when the pile head is chiseled off, the reinforcing steel bars are stripped one by one from outside to inside, the reinforcing steel bars cannot be damaged, after the pile head is completely stripped off, the pile head is chiseled off from the cutting mark, the chiseled-off pile head is vertically adjusted and transported away, then the rest pile foundation head is chiseled off manually, and the surrounding laitance is removed;
and (4) detecting the pile by adopting ultrasonic after the pile head is broken, and constructing the concrete of the joist part after the detection is qualified.
By utilizing the pile head circular cutting construction process, the main reinforcement at the top end of the pile foundation can be exposed, after the concrete of the joist part is constructed, the reinforcement at the top end of the pile foundation is inserted into the joist, and the pile foundation and the joist form an organic whole.
Referring to fig. 1, the construction of the counter-balanced retaining wall includes the following steps:
after the joist construction is finished, erecting a scaffold, erecting a wall formwork and installing a water drain pipe; pouring wall concrete, removing the formwork and curing the concrete; and backfilling the wall backs.
Referring to fig. 7, when the wall back is backfilled, a sand filtering layer 100 and a gravel layer 200 are sequentially formed on the back surface of the constant weight retaining wall, and the sand filtering layer 200 is arranged between the back surface of the constant weight retaining wall and the gravel layer 100; the water inlet end of the water drain pipe is positioned in the sand filter layer 200, and the water inlet end of the water drain pipe is wrapped with geotechnical filter cloth.
Specifically, the gravel layer 200 is generally formed by piling up coarse-grained materials (large-grained gravel or pebbles), the sand filter 5 is generally formed by fine-grained gravel, a flexible water permeable pipe is preferably used as the drain pipe, and the length of the drain pipe extending into the sand filter 5 is generally not less than 0.15 m. In addition, the drain pipes are obliquely arranged, the outward drainage gradient of the drain pipes is not less than 4%, and the outlet of the drain hole in the lowest row is preferably higher than the ground by more than 30 cm; the drain pipe in the wall should be installed and positioned when the formwork is erected. According to the invention, the gravel layer 200, the sand filter layer 100 and the geotechnical filter cloth form a triple filter structure, so that piping and soil flow can be effectively prevented.
Preferably, the outlet pipe is the layering and arranges, is provided with soft pervious pipe 7 in the outlet pipe corresponding position of lowest floor, and soft pervious pipe 7 is pre-buried in sand filtration layer 100, and soft pervious pipe 300 arranges along the length direction of weighing type retaining wall 3, and soft pervious pipe 300 passes through outer drainage system of pipeline intercommunication or directly is connected with the outlet pipe. The soft water permeable pipe 300 arranged in the length direction of the balance weight type retaining wall 3 forms a vertical drainage structure, and the drainage effect can be further improved. According to different terrains, the longitudinal drainage structure can realize different drainage modes. The flexible permeable pipe 300 forms a longitudinal drainage seepage ditch which can be used for longitudinally guiding water according to a one-way slope or a herringbone slope, and can also form a concave slope when being limited by terrain conditions, and the lowest part of the concave slope is provided with a water drainage hole for guiding water out of a roadbed. In the present embodiment, the technical standard of the flexible water permeable tube 300 is as follows: 50mm in inner diameter, longitudinal tensile strength: 1.46KN/5cm, CBR burst strength: 4.07KN, permeability coefficient: 2.75X10cm-1 cm/s.
For better drainage effect, the preferable arrangement mode of the drain pipe is as follows: the drain pipes on each layer are uniformly arranged at intervals, and the drain pipes on two adjacent layers are arranged in a staggered manner, namely the drain pipes on the odd-numbered layers are mutually aligned, the drain pipes on the even-numbered layers are mutually aligned, and the drain pipes on the odd-numbered layers and the drain pipes on the even-numbered layers are arranged in a staggered manner.
In addition, the position of the water inlet end of the water drain pipe at the lowest layer is higher than the position of the side slope rock-soil interface at the back of the balance weight type retaining wall 3, a geomembrane is arranged on the side slope rock-soil interface at the back of the balance weight type retaining wall 3, and the sand filter layer 100 and the gravel layer 200 are both arranged on the geomembrane. The geomembrane can form an anti-seepage structure, and is beneficial to concentrated water seepage and discharge. The geomembrane can also be combined with waterproof geotextile for implementation, and a mode of two cloths and one film is generally adopted.
Claims (8)
1. The construction method of the pile foundation joist constant weight type retaining wall sequentially comprises the following steps of pile foundation construction, joist construction and constant weight type retaining wall construction; the method is characterized in that pile foundation construction comprises the following steps:
leveling the field, and building a pile foundation construction platform;
embedding a pile casing;
drilling construction is carried out by adopting a rotary drilling rig, and the wall is protected by mud; in the drilling process, the lost and leaked slurry is replenished in time, so that the liquid level of the slurry is 1.0-1.5 m higher than the water level outside the hole or the underground water level;
when the drilling depth reaches the design requirement, checking the hole depth, the hole diameter and the hole shape, and cleaning the hole after confirming that the design requirement is met;
after hole cleaning is finished, installing a reinforcement cage; when the reinforcement cage is hoisted, two-point hoisting is adopted, wherein a first hoisting point is arranged at the top end of the reinforcement cage, a second hoisting point is arranged at the side edge of the reinforcement cage, the position which is apart from the bottom end of the reinforcement cage by the length 1/3 of the reinforcement cage is taken as a positioning mark point, and the second hoisting point is positioned between the positioning mark point and the middle point of the reinforcement cage in the length direction; when in lifting, the first lifting point is lifted firstly to slightly lift the steel reinforcement cage, then the steel reinforcement cage is lifted simultaneously with the second lifting point, the second lifting point is slowly loosened along with the continuous rising of the steel reinforcement cage until the steel reinforcement cage is vertical to the ground or a platform, the lifting of the second lifting point is stopped, the steel reinforcement cage is lifted to be right above the pile hole by the first lifting point, and then the steel reinforcement cage is lifted and placed into the pile hole; the upper end of the reinforcement cage is positioned and fixed at the orifice;
installing a guide pipe, cleaning the hole by using the guide pipe, continuously pumping fresh slurry into the bottom of the hole by using a slurry pump through the guide pipe, and replacing sediments at the bottom of the hole;
and after hole cleaning is finished, pouring concrete by using the guide pipe.
2. The method of constructing a pile foundation joist counterweight retaining wall as claimed in claim 1, wherein: the steel reinforcement cage structure in the pile foundation construction is as follows: the reinforcement cage comprises a plurality of vertical main reinforcements (1) parallel to the axis of the reinforcement cage, the vertical main reinforcements (1) are distributed at intervals along the circumferential direction of the reinforcement cage, spiral stirrups (2) are arranged outside a cylindrical structure surrounded by the vertical main reinforcements (1), the spiral stirrups (2) are spirally distributed by taking the axis of the reinforcement cage as a central axis, the spiral stirrups (2) are fixedly connected with the vertical main reinforcements (1), reinforcement stirrups (3) are arranged in a cylindrical inner cavity surrounded by the vertical main reinforcements (1), the reinforcement stirrups (3) are circular, the reinforcement stirrups (3) are arranged at intervals along the length direction of the vertical main reinforcements (1), and the reinforcement stirrups (3) and the vertical main reinforcements (1) are welded and fixed; the inner ring of the reinforcement stirrup (3) is provided with a cross reinforcing rib (4), and the cross reinforcing rib (4) is fixedly connected with the reinforcement stirrup (3) in a spot welding manner;
when a reinforcement cage is manufactured, the reinforcement stirrups (3) and the cross reinforcing ribs (4) are processed into an integral structure in advance, then the reinforcement stirrups (3) are placed according to a set interval, the connecting positions of the vertical main reinforcements (1) are marked on the reinforcement stirrups (3) at equal intervals, 6-8 vertical main reinforcements (1) are sequentially welded on the reinforcement stirrups (3) one by one to form a reinforcement framework, then other vertical main reinforcements (1) are uniformly welded on the reinforcement framework to form the whole framework, and finally the spiral stirrups (2) are bound or fixed on the reinforcement framework according to the designed drawing interval in a spot welding mode to manufacture the reinforcement cage;
when the steel reinforcement cage is hung and put into the hole, the cross reinforcing rib (4) is gradually removed in the lowering process of the steel reinforcement cage in a cutting mode, the steel reinforcement cage is lowered to the set height after the cross reinforcing rib (4) on the first layer is removed, then the cross reinforcing rib (4) on the second layer is removed, and the operation is repeated until the steel reinforcement cage is hung and put into the hole.
3. The method of constructing a pile foundation joist counterweight retaining wall as claimed in claim 2, wherein: in the structure of the steel reinforcement cage, positioning steel bars (5) are arranged outside a cylindrical structure enclosed by vertical main reinforcements (1), two ends of each positioning steel bar (5) are provided with connecting sections (51) for fixedly connecting the vertical main reinforcements (1), and the connecting sections (51) are parallel to the vertical main reinforcements (1) and are welded and fixed with the vertical main reinforcements (1); the middle part of the positioning steel bar (5) is bent to form a positioning bulge which is arranged in a convex way relative to the steel bar cage, the top part of the positioning bulge is a straight line section (53) which is parallel to the vertical main steel bar (1), and two sides of the straight line section (53) are connected with the connecting section (51) through inclined line sections (52); a plurality of groups of positioning steel bars (5) are arranged at intervals along the length direction of the steel bar cage, and each group of positioning steel bars (5) is at least three pieces arranged at intervals along the circumferential direction of the steel bar cage; the tops of the positioning bulges of the multiple groups of positioning steel bars (5) are all positioned on the same cylindrical surface, and the cylindrical surface and the steel bar cage are coaxially arranged; the bottom ends of the vertical main ribs (1) are all bent inwards to form inclined sections, and the inclined sections and the vertical extension lines of the bottom ends of the vertical main ribs (1) form included angles of 4-6 degrees.
4. The method of constructing a pile foundation joist counterweight retaining wall as claimed in claim 1, wherein: in pile foundation construction, when concrete is poured, a measuring hammer is used for measuring the position of a concrete surface, and a guide pipe is lifted in time, so that the length of the concrete embedded in the guide pipe is controlled within the range of 2-6 m; the elevation of the top surface of the concrete pouring is controlled to be 0.5-1.5 m higher than the designed elevation of the pile top.
5. The method of constructing a pile foundation joist counterweight wall as claimed in claim 1 wherein the joist construction includes the steps of:
after pile foundation construction is completed, excavating a foundation pit and protecting;
marking a cutting line of the pile head by using paint according to the pile head elevation position of the pile foundation concrete, and cutting 2-4 cm deep cutting marks along the cutting line by using a cutting machine by an operator;
chiseling off the pile head above the cutting line by using an air compressor; when the pile head is chiseled off, the reinforcing steel bars are stripped one by one from outside to inside, the reinforcing steel bars cannot be damaged, after the pile head is completely stripped off, the pile head is chiseled off from the cutting mark, the chiseled-off pile head is vertically adjusted and transported away, then the rest pile foundation head is chiseled off manually, and the surrounding laitance is removed;
and (4) detecting the pile by adopting ultrasonic after the pile head is broken, and constructing the concrete of the joist part after the detection is qualified.
6. The method for constructing a pile foundation joist weighted retaining wall as claimed in any one of claims 1 to 5 wherein the construction of the weighted retaining wall includes the steps of:
after the joist construction is finished, erecting a scaffold, erecting a wall formwork and installing a water drain pipe; pouring wall concrete, removing the formwork and curing the concrete; backfilling the wall back;
when the wall back is backfilled, a sand filtering layer (100) and a crushed stone layer (200) are sequentially formed on the back of the constant weight retaining wall, and the sand filtering layer (200) is arranged between the back of the constant weight retaining wall and the crushed stone layer (100); the water inlet end of the water drain pipe is positioned in the sand filter layer (200), and the water inlet end of the water drain pipe is wrapped with geotechnical filter cloth.
7. The method for constructing a pile foundation joist-type retaining wall according to claim 6, wherein in the construction of the retaining wall, the water drain pipes are arranged in layers, the soft water permeable pipe (300) is arranged at the corresponding position of the water drain pipe at the lowest layer, the soft water permeable pipe (300) is pre-embedded in the sand filtering layer (200), the soft water permeable pipe (300) is arranged along the length direction of the retaining wall, and the soft water permeable pipe (300) is communicated with an external water drainage system through a pipeline or is directly connected with the water drain pipe.
8. The method for constructing a pile foundation joist retaining wall according to claim 6 wherein in the construction of the retaining wall, the water inlet end of the water drain pipe at the lowest layer is higher than the position of the interface of the slope rock soil at the back of the retaining wall, a geomembrane is arranged at the interface of the slope rock soil at the back of the retaining wall, and the sand filter layer (200) and the gravel layer (300) are arranged on the geomembrane.
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| CN202010505267.1A CN111622216A (en) | 2020-06-05 | 2020-06-05 | Construction method of pile foundation joist weighing type retaining wall |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114012004A (en) * | 2021-10-20 | 2022-02-08 | 中交路桥华南工程有限公司 | Pier column reinforcement cage installation method |
| CN114197516A (en) * | 2020-09-17 | 2022-03-18 | 云南宏图工程设计有限公司 | Integrated anti-sliding pile foundation joist retaining wall and construction method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105002927A (en) * | 2015-06-15 | 2015-10-28 | 湖北工业大学 | Construction method for excavation slope retaining wall reversed filter layer |
| CN107246006A (en) * | 2017-06-29 | 2017-10-13 | 深圳市蛇口招商港湾工程有限公司 | Concrete-pile reinforcement cage structure and pile-filling method |
| CN207714309U (en) * | 2017-11-09 | 2018-08-10 | 上海工程勘察设计有限公司 | Borehole filling pile cage of reinforcement |
-
2020
- 2020-06-05 CN CN202010505267.1A patent/CN111622216A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105002927A (en) * | 2015-06-15 | 2015-10-28 | 湖北工业大学 | Construction method for excavation slope retaining wall reversed filter layer |
| CN107246006A (en) * | 2017-06-29 | 2017-10-13 | 深圳市蛇口招商港湾工程有限公司 | Concrete-pile reinforcement cage structure and pile-filling method |
| CN207714309U (en) * | 2017-11-09 | 2018-08-10 | 上海工程勘察设计有限公司 | Borehole filling pile cage of reinforcement |
Non-Patent Citations (3)
| Title |
|---|
| 上海铁路局: "《高速铁路施工工序管理要点，第一册，桥梁钻孔桩基础》", 30 September 2010, 中国铁道出版社 * |
| 刘为东等: "《梅州城区广州大桥斜拉桥施工测量技术》", 30 April 2015 * |
| 杨洲: ""浅议桩基托梁挡土墙在库区公路中的应用"", 《四川水泥》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114197516A (en) * | 2020-09-17 | 2022-03-18 | 云南宏图工程设计有限公司 | Integrated anti-sliding pile foundation joist retaining wall and construction method thereof |
| CN114012004A (en) * | 2021-10-20 | 2022-02-08 | 中交路桥华南工程有限公司 | Pier column reinforcement cage installation method |
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Application publication date: 20200904 |