CN113026760A - Combined type supporting pile for double-element foundation pit of soil and rock and construction method thereof - Google Patents
Combined type supporting pile for double-element foundation pit of soil and rock and construction method thereof Download PDFInfo
- Publication number
- CN113026760A CN113026760A CN202110241419.6A CN202110241419A CN113026760A CN 113026760 A CN113026760 A CN 113026760A CN 202110241419 A CN202110241419 A CN 202110241419A CN 113026760 A CN113026760 A CN 113026760A
- Authority
- CN
- China
- Prior art keywords
- pile
- piles
- soil
- cast
- rock
- 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.)
- Pending
Links
- 239000011435 rock Substances 0.000 title claims abstract description 79
- 238000010276 construction Methods 0.000 title claims abstract description 24
- 239000002689 soil Substances 0.000 title claims description 63
- 238000004873 anchoring Methods 0.000 claims abstract description 71
- 229910000831 Steel Inorganic materials 0.000 claims description 80
- 239000010959 steel Substances 0.000 claims description 80
- 230000003014 reinforcing effect Effects 0.000 claims description 44
- 230000002787 reinforcement Effects 0.000 claims description 34
- 239000010410 layer Substances 0.000 claims description 33
- 239000002131 composite material Substances 0.000 claims description 28
- 238000005553 drilling Methods 0.000 claims description 22
- 239000004567 concrete Substances 0.000 claims description 21
- 239000000463 material Substances 0.000 claims description 15
- 238000004364 calculation method Methods 0.000 claims description 12
- 238000013461 design Methods 0.000 claims description 11
- 238000011835 investigation Methods 0.000 claims description 9
- 238000012360 testing method Methods 0.000 claims description 9
- 239000004568 cement Substances 0.000 claims description 8
- 238000009412 basement excavation Methods 0.000 claims description 6
- 230000001681 protective effect Effects 0.000 claims description 6
- 239000002002 slurry Substances 0.000 claims description 6
- 239000002344 surface layer Substances 0.000 claims description 6
- 231100000817 safety factor Toxicity 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 5
- 238000003466 welding Methods 0.000 claims description 5
- 239000011083 cement mortar Substances 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 238000004140 cleaning Methods 0.000 claims description 3
- 238000002474 experimental method Methods 0.000 claims description 3
- 238000007667 floating Methods 0.000 claims description 3
- 230000009467 reduction Effects 0.000 claims description 3
- 238000010008 shearing Methods 0.000 claims description 3
- 239000011378 shotcrete Substances 0.000 claims description 3
- 239000000758 substrate Substances 0.000 claims description 3
- 230000008878 coupling Effects 0.000 claims description 2
- 238000010168 coupling process Methods 0.000 claims description 2
- 238000005859 coupling reaction Methods 0.000 claims description 2
- 239000007921 spray Substances 0.000 claims description 2
- 230000000087 stabilizing effect Effects 0.000 claims description 2
- 230000004931 aggregating effect Effects 0.000 claims 1
- 229910001294 Reinforcing steel Inorganic materials 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 238000005422 blasting Methods 0.000 description 2
- 238000007596 consolidation process Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000009527 percussion Methods 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000004642 transportation engineering Methods 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/02—Foundation pits
- E02D17/04—Bordering surfacing or stiffening the sides of foundation pits
-
- 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
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/13—Architectural design, e.g. computer-aided architectural design [CAAD] related to design of buildings, bridges, landscapes, production plants or roads
Landscapes
- Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Physics & Mathematics (AREA)
- Mining & Mineral Resources (AREA)
- General Engineering & Computer Science (AREA)
- Geometry (AREA)
- Civil Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Computer Hardware Design (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Paleontology (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Evolutionary Computation (AREA)
- Computational Mathematics (AREA)
- Architecture (AREA)
- Piles And Underground Anchors (AREA)
Abstract
The invention provides a soil-rock double-element foundation pit combined type supporting pile and a construction method thereof. Compared with the prior art, the invention has the advantages of simple, safe, quick, environment-friendly and economic construction, and is particularly suitable for the construction of the soil-rock double-element foundation pit close to the existing underground structure; according to the invention, the safety coefficient of the integral stability of the side wall of the foundation pit and the anchoring length of the micro pile are checked before construction, so that the safety of the foundation pit is improved.
Description
Technical Field
The invention belongs to the technical field of constructional engineering, and particularly relates to a soil-rock double-element foundation pit combined type supporting pile and a construction method thereof.
Background
With the acceleration of urbanization processes in various regions and the development of automobile industry, basement foundation pit support is increasingly becoming a key technology of construction engineering, the condition that foundation pits to be excavated in urban areas are close to existing basements (or other structures) is increasing, the traditional pile anchor support is difficult to realize due to limited space, the double-row pile support technology is mostly adopted, and for soil-rock double-element foundation pits of upper soil layers and lower rock layers, the rock hardness and the rock entering problem of large-diameter cast-in-place piles are always the construction difficulty of supporting piles.
The existing cast-in-place pile rock-entering process mainly comprises the following steps:
a. drilling a hole by using a percussion drill, hammering a rock mass into powder by using a heavy hammer, and performing slurry circulation to remove slag and form the hole;
b. manually digging a hole pile, wherein after a rock stratum is loosened by adopting a blasting method, a pneumatic pick and a shovel are manually used for deslagging and forming a hole;
c. drilling a hole by rotary drilling, and coring and forming the hole in the rock body by matching with a special roller bit for the rock body;
d. the pile driver is matched with a large-diameter down-the-hole hammer to form a hole.
The above methods are high in cost, and the impact drilling hole-forming slurry is seriously polluted and has large vibration; the blasting construction of the manual hole digging pile close to the building has potential safety hazards and large vibration; the rotary drilling efficiency is slow, and the noise is high; the large-diameter down-the-hole hammer has large dust amount, serious environmental pollution, large noise and large vibration.
Through the retrieval, patent name "a cable resistance to plucking device of anchor at pile bottom", the utility model patent of patent number 201020228027, it discloses for set up at the pile body center with pile body unbonded non-prestressing force cable, set up anchor device connection cable bottom the pile body, the cable top is connected with structural foundation adoption steel anchor plate. The device aims to press the whole section of the pile body, enhance the anti-cracking capability of the pile body and improve the anti-pulling economy of the pile. This patent does not relate to the rock-socketed problem of the bored concrete pile and the function of the earth-retaining bearing horizontal load.
In the related documents, in 10 months of 1998, the Zhanming ' rock-socketed pile bearing capacity calculation and pile bottom anchoring type ' published in the Water transportation engineering ' mainly describes the rock-socketed anchoring type of port foundation piles, but not the solution of great rock-socketed difficulty of cast-in-place piles and the function of horizontal load bearing of retaining soil.
Disclosure of Invention
The invention provides a soil-rock double-element foundation pit combined type support pile and a construction method thereof, which can solve the problems of serious mud pollution, high noise, low speed and high manufacturing cost in the prior art for the rock-socketed construction of a soil-rock double-element foundation pit cast-in-place pile of an upper soil layer and a lower rock layer.
In order to solve the technical problems, the combined type supporting pile for the soil-rock double-element foundation pit provided by the invention is realized by adopting the following technical scheme: the combined type supporting pile for the double-element foundation pit of the soil and rock comprises a first row of combined piles and a second row of combined piles, wherein the second row of combined piles has the same structure as the first row of combined piles and is positioned on the outer side of the first row of combined piles, and the top ends of the first row of combined piles and the second row of combined piles are connected into a whole through crown beams and connecting beams; the first row of composite piles comprise a plurality of composite piles arranged along the side wall of the foundation pit at intervals, each composite pile comprises a cast-in-place pile and a plurality of miniature piles located below the cast-in-place pile, the cast-in-place piles are located in the soil layer, the bottom ends of the cast-in-place piles are embedded into upper soft rock of the rock layer, the miniature piles are located in the rock layer, each miniature pile comprises a first anchoring section and a second anchoring section, the second anchoring section is located below the first anchoring section and located in lower hard rock of the rock layer, and the first anchoring section is embedded into and anchored in the rock entering section of the cast-in-place piles.
Bored concrete pile including cast-in-place concrete, steel reinforcement cage and with the fixed steel pipe of miniature stake one-to-one, fixed steel pipe runs through the top and the bottom of body bored concrete pile, fixed steel pipe is equipped with the fixed reinforcing bar of determining the interval, fixed reinforcing bar with steel reinforcement cage welding is as an organic whole and hoop establishes on the fixed steel pipe.
The inner diameter of the fixed steel pipe is 146-219mm, the wall thickness is 3-5mm, and the diameter of the micro pile is 15-25mm smaller than the inner diameter of the fixed steel pipe.
And the combined piles of the first row of combined piles and the combined piles of the second row of combined piles are aligned one by one.
And cement-soil piles are arranged between adjacent cast-in-place piles of the first row of composite piles.
The invention also provides a construction method of the soil-rock double-element foundation pit combined type support pile, which comprises the following steps:
1) setting the whole stability safety coefficient trial calculation of the combined support piles for the foundation pit, checking whether the reinforcement of the miniature pile is safe and reasonable or not, and adjusting the reinforcement of the miniature pile according to the whole stability safety coefficient;
the overall stability safety coefficient is calculated by trial by adopting the following formula (4):
K=Mk/Mq...........................................（4）；
in the formula:
Mk=∑cikli+∑(q0bi+wi)cosθitgϕik+2kγsTA/b;
Mq=∑(q0bi+wi)sinθi;
in the formula, K is the integral stability safety coefficient; the safety grades are a first-grade foundation pit, a second-grade foundation pit and a third-grade foundation pit respectively, and the corresponding overall stability safety factors are not less than 1.35, 1.3 and 1.25 respectively;
Mkthe anti-skid moment is generated for rock and soil at a certain slip crack surface and the combined type supporting pile;
Mqthe gliding moment is generated by rock soil and load above a certain sliding crack surface;
cikobtaining data through geotechnical engineering investigation for the consolidation non-drainage shear cohesive force of soil on the ith soil strip slip surface on a certain slip surface;
ϕikobtaining data for the standard value of the internal friction angle of soil on the ith soil strip slip surface on a certain slip surface through geotechnical engineering investigation;
bitaking a value for the width of the ith soil strip by a designer according to experience;
liis the slip surface length of the ith soil strip, li=bi/cosθi；
wiCalculating the weight of the ith soil strip acting on the slip crack surface according to the weight of the natural soil of the overlying soil layer, and acquiring data through a geotechnical engineering investigation report, wherein each geotechnical layer is accumulated;
θian included angle between the normal of the midpoint of the slip crack line segment of the ith soil strip and the vertical plane;
q0in order to act on the load on the foundation pit surface, a designer takes values according to the field condition and the subsequent use condition;
γsthe coefficient is used for exerting the shear strength of the micro pile, and is an empirical coefficient or is determined through experiments;
k is the number of the micro piles arranged below each cast-in-place pile, and the number is set by a designer according to experience;
t is a shear strength standard value of the reinforcing bars of the single miniature pile at the sliding surface;
a is the cross-sectional area of the reinforcing bars of a single miniature pile, and when a plurality of reinforcing bars are arranged, A is the accumulated cross-sectional area of the plurality of reinforcing bars;
b is the center distance of adjacent cast-in-place piles in the first row of composite piles and the second row of composite piles;
performing overall stability safety coefficient trial calculation respectively by arranging a plurality of slip fracture surfaces and different micro pile reinforcing bars to obtain a plurality of overall stability safety coefficients, and if the minimum value meets the design requirement, integrally stabilizing the side wall of the foundation pit and determining the corresponding micro pile reinforcing bars;
2) checking the anchoring length L1 of the first anchoring section and the anchoring length L2 of the second anchoring section of the micro-pile, and the anchoring length t below the embedded substrate;
wherein, the anchoring length L1 is checked by adopting the following formula (1), if the anchoring length L1 does not satisfy the formula (1), the L1 is adjusted until the formula (1) is satisfied:
L1≥Rk,j/(πDfd)...........................................（1）；
in the formula:
Rk,jobtaining a standard value of ultimate uplift bearing capacity of reinforcing bars for the miniature pile according to a corresponding material standard;
d is the inner diameter of a fixed steel pipe serving as a drilling channel in the cast-in-place pile, and is an empirical value;
fdselecting or selecting a standard value of the bonding strength between the inner wall of the fixed steel pipe in the cast-in-place pile and a grouting material according to related standards or tests;
the anchoring length L2 is checked by adopting the following formula (2), and if the anchoring length L2 does not satisfy the formula (2), L2 is adjusted until the formula (2) is satisfied:
L1/L2≥Rk,j /(πξnrfb) ...........................................（2）；
in the formula:
Rk,jobtaining a standard value of ultimate uplift bearing capacity of reinforcing bars for the miniature pile according to a corresponding material standard;
r is the diameter of the grouting anchoring body of the cast-in-place pile, and is an empirical value;
fdselecting or selecting a standard value of the bonding strength between the inner wall of the fixed steel pipe in the cast-in-place pile and a grouting material according to related standards or tests;
n is the reinforcement count of the micro pile and is an empirical value;
xi is the reduction coefficient of the bonding strength, when the number of the reinforcing bars of the miniature pile is 3, xi is 0.7, and when the number of the reinforcing bars of the miniature pile is 4, xi is 0.55;
the anchoring length t is calculated by adopting the following formula (3):
t/L2≥Rk,j /(πrqsik) ...........................................（3）；
in the formula:
Rk,jobtaining a standard value of ultimate uplift bearing capacity of reinforcing bars for the miniature pile according to a corresponding material standard;
r is the diameter of the grouting anchoring body of the cast-in-place pile, and is an empirical value;
qsikselecting or selecting a bonding strength standard value of the micro pile grouting anchoring body in the hard rock of the rock stratum according to related standards or tests;
taking the larger value of L1 and L2 obtained by checking the formulas (1), (2) and (3) as the design value;
3) constructing pile holes of a cast-in-place pile, forming final holes when the holes reach rock stratum hard rock, manufacturing a reinforcement cage according to the depth of the pile holes, and welding and fixing fixed steel pipes which correspond to the designed micro piles one by one on the inner side of the reinforcement cage to be used as drilling channels;
4) plugging measures are taken at the bottom end and the top end of a fixed steel pipe fixed in the steel reinforcement cage to prevent poured concrete from entering the fixed steel pipe, and anti-floating pressure or fixing measures of the steel reinforcement cage and the fixed steel pipe are taken at the orifice of a pile hole;
5) cleaning cement soil and concrete at the top end of the cast-in-place pile, exposing the steel bars of the cast-in-place pile and the head of the fixed steel pipe, binding the crown beam and the connecting beam steel bars, pouring concrete, and forming the crown beam and the connecting beam;
6) drilling the miniature pile by taking a fixed steel pipe fixed in the reinforcement cage as a drilling channel;
7) placing a pile core of the micro pile, pouring cement mortar or pure cement slurry into the micro pile and the fixed steel pipe, and anchoring the micro pile and the poured pile into a whole;
8) and excavating the side of the foundation pit in layers, and constructing a protective surface layer in layers.
And a step of constructing a waterproof curtain on the inner side of the cast-in-place pile of the first row of combined piles is also arranged between the step 4) and the step 5).
And 8) constructing the side protective surface layer of the foundation pit excavation in the step 8) by adopting a hanging net to spray concrete, wherein the diameter of a net rib is 4-8mm, the diameter of a grid is 200-300mm, the label of the sprayed concrete is C20, and the thickness is 60-100 mm.
Compared with the prior art, the invention has the following advantages and positive effects:
1. the two rows of combined piles of the soil-rock double-element foundation pit combined type supporting pile are connected into a supporting whole by the top crown connecting beam, and both comprise a filling pile of an upper soil layer and a plurality of miniature piles which are lengthened by rock entering at the lower part, the miniature piles replace the filling piles to be embedded and fixed in the rock entering, and the pile holes of the filling piles are formed by adopting a conventional method, so that the construction speed is high; the diameter of the miniature pile is much smaller than that of the cast-in-place pile, the diameter of a rock-entering drill hole is small, and the miniature pile can be directly placed into a fixed steel pipe fixed on a steel reinforcement cage of the cast-in-place pile for drilling by adopting a drill bit drill rod, so that the miniature pile is easy to enter the rock; compared with the prior art, the invention has the advantages of simple construction, safety, rapidness, environmental protection and economy, and is particularly suitable for supporting the soil-rock double-element foundation pit close to the existing underground structure;
2. in the stage of determining support construction parameters, trial calculation is carried out on the safety coefficient of the overall stability of the side wall of the foundation pit, the set shear strength of the miniature pile is participated in the overall stability checking calculation of the side wall, and the safety coefficient can meet the minimum requirement of foundation pits of different levels; the anchoring lengths L1, L2 and t of the micro piles are respectively checked, bonding damage failure between a grouting anchoring body in a reserved fixed steel pipe and the inner wall of the reserved fixed steel pipe in the cast-in-place pile after the foundation pit excavation supporting structure is stressed is avoided, bonding damage failure of reinforcing bars of the micro piles inside and outside the cast-in-place pile and the grouting anchoring body is avoided, bonding damage failure between the grouting anchoring body of the micro piles below the foundation bed and surrounding rocks is avoided, and the safety of the foundation pit is guaranteed.
Drawings
FIG. 1 is a schematic view of a dual-element earth and rock foundation pit near an existing underground structure with the combined type support piles for the dual-element earth and rock foundation pit of the invention;
FIG. 2 is a C-direction view of the soil-rock double-foundation-pit combined type support pile in FIG. 1;
FIG. 3 is a sectional view taken along line A-A of FIG. 1;
fig. 4 is a sectional view taken along line B-B of fig. 1.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
First, the terms "inner" and "outer" in the present embodiment are described, where the direction close to the center of the structure is "inner" and the direction away from the center of the structure is "outer", and for example, the foundation pit is taken as an example, the direction close to the center of the foundation pit is "inner" and the direction away from the center of the foundation pit is "outer".
Referring to fig. 1 to 2, the soil-rock double-element foundation pit combined type supporting pile 1 of the embodiment includes a first row of combined piles 100 and a second row of combined piles 200, where the second row of combined piles 200 has the same structure as the first row of combined piles 100 and the second row of combined piles 200 is located outside the first row of combined piles 100, that is, the first row of combined piles 100 is close to the excavation side of a foundation pit, and the second row of combined piles 200 is close to an existing underground structure 5; the top ends of the first row of the composite piles 100 and the second row of the composite piles 200 are connected into a whole by the crown beam 300 and the coupling beam 400; since the two rows of composite piles are identical, only the first row 100 of composite piles will be described.
Specifically, the first row of composite piles 100 includes a plurality of composite piles 110 arranged at intervals along the side wall of the foundation pit, each composite pile 110 includes a cast-in-place pile 111 and a plurality of micro piles 112 located below the cast-in-place pile 111, the cast-in-place pile 111 is located in the soil layer 2, the bottom end of the cast-in-place pile 111 is embedded in the upper soft rock 3-1 of the rock layer 3, the micro piles 112 are located in the rock layer 3, each micro pile 112 includes a first anchoring section 112-1 and a second anchoring section 112-2 located below the first anchoring section 112-1 and located in the lower hard rock 3-2 of the rock layer 3, and the first anchoring section 112-1 is embedded and anchored in the cast-in-place pile 111. The number of the micro-piles 112 corresponding to each cast-in-place pile 111 can be 3-6 according to the diameter of the cast-in-place pile 111.
In the embodiment, the two rows of combined piles of the soil-rock double-element foundation pit combined type supporting pile are connected into a supporting whole by the top crown connecting beam, so that the stability of the whole structure is improved, and the stability of the supporting is further improved; each combined pile comprises a cast-in-place pile of an upper soil layer and a plurality of miniature piles which are lengthened by rock entering at the lower part, the miniature piles replace the cast-in-place piles to be embedded and fixed in the rock entering, and the pile holes of the cast-in-place piles are formed by adopting a conventional method, so that the construction speed is high; the diameter of the miniature pile is much smaller than that of the cast-in-place pile, the diameter of a rock-entering drill hole is small, and the miniature pile can be directly placed into a fixed steel pipe fixed on a steel reinforcement cage of the cast-in-place pile for drilling by adopting a drill bit drill rod, so that the miniature pile is easy to enter the rock; compared with the prior art, the double-row pile supporting structure has the advantages of simple construction, safety, rapidness, environmental protection and economy, and is particularly suitable for supporting the soil-rock double-element foundation pit close to the existing underground structure.
Further, referring to fig. 3, in the embodiment, the cast-in-place pile 111 includes cast-in-place concrete 111-2, a reinforcement cage 111-3, and fixed steel pipes 111-4 corresponding to the micro-piles 112 one by one, the fixed steel pipes 111-4 serve as pile hole drilling channels of the micro-piles and penetrate through the top end and the bottom end of the cast-in-place pile 111, a plurality of fixed steel bars 111-1 are arranged on the fixed steel pipes at intervals along the axial direction of the fixed steel pipes, the fixed steel bars 111-1 and the reinforcement cage 111-3 are welded into a whole and are hooped on the fixed steel pipes 111-4, so as to maintain the stable verticality of the fixed steel pipes after the.
Referring to fig. 4, the micro pile 112 includes a grouting anchor 112-3, a positioning bracket 112-4 embedded in the grouting anchor 112-3, a plurality of reinforcing bars 112-5, and a fixing short reinforcing bar 112-6 located in the central axis direction, the positioning bracket 112-4, the plurality of reinforcing bars 112-5, and the fixing short reinforcing bar 112-6 are welded together, and the positioning bracket 112-4 is used for positioning the reinforcing bar 112-5 to center the reinforcing bar 112-5. When the micro pile 112 is constructed, the fixed steel pipe 111-4 in the cast-in-place pile 111 is used as a drilling channel, a drill bit drill rod is directly placed into the fixed steel pipe 111-4 to drill, the drilling machine generally selects a water well drill or a down-the-hole drill and the like, a micro pile core, namely a positioning bracket 112-4, a reinforcing bar 112-5 and a short reinforcing bar 112-6 are installed into a hole, then cement mortar or pure cement slurry (P.O42.5 grade is generally suitable for cement) is poured into the hole of the fixed steel pipe 111-4 and the hole of the micro pile 112, so that the first anchoring section 112-1 of the cast-in-place pile 111 and the micro pile 112 are anchored into a whole, and the second anchoring section 112-2 and the hard rock 3-2 of the rock stratum 3 are. The reinforcing bars 112-5 can be made of deformed steel bars, seamless steel pipes, I-shaped steel bars or small steel reinforcement cages.
The inner diameter of the fixed steel pipe 111-4 is preferably 146-.
Preferably, as shown in fig. 2, the composite piles 110 of the first row of composite piles 100 and the composite piles 210 of the second row of composite piles 200 are aligned one to one. The diameter R of the cast-in-place pile 111 is generally 0.8-1.2m, the row distance a of the first row of combined piles 100 and the second row of combined piles 200 is preferably 2R-5R, the center distance b of two adjacent cast-in-place piles 111 is preferably 1.5R-3R, the width of the crown beam 300 and the width of the connecting beam 400 are preferably R- (R +20cm), the height of the crown beam 300 and the height of the connecting beam 400 are preferably 0.8R-R, the height of the connecting beam 400 is not less than the height of the crown beam 300, the ratio of the height of the connecting beam 400 to the row distance a is preferably 1/5-1/4, the concrete labels of the cast-in-place piles 111, the crown beam 300 and the connecting beam 400 are preferably C25-C35, and the reinforcing steel bar cage 111-3 reinforcing steel bar of the cast-in-place pile 111 can be circular uniform.
Further, as shown in fig. 2, a cement-soil pile 500 is disposed between adjacent cast-in-place piles 111 of the first row of composite piles 100, and the cement-soil pile 500 and the cast-in-place pile 110 are connected together to form a waterproof curtain together with the cast-in-place piles 111. Of course, in order to further improve the water stopping effect, cement-soil piles may be constructed between the adjacent cast-in-place piles 211 of the second row of composite piles 200 to form a double row of water stopping curtains.
The embodiment also provides a construction parameter checking and calculating method for the soil-rock double-element foundation pit combined type supporting pile, which is used for carrying out overall stability safety coefficient trial calculation and judging the minimum value in order to ensure the overall stability of the combined supporting pile structure after the foundation pit is excavated; meanwhile, in order to ensure that the bonding damage between the grouting anchor body in the fixed steel pipe 111-4 in the cast-in-place pile and the inner wall of the fixed steel pipe 111-4 is failed after the foundation pit excavation supporting pile is stressed, the anchoring length L1 of the micro pile 112 in the fixed steel pipe 111-4 needs to be ensured to meet the requirement, and in order to avoid the bonding damage between the grouting anchor body of the micro pile 112 below the foundation 4 and the surrounding rock, the anchoring length t between the grouting anchor body of the micro pile 112 below the foundation 4 and the surrounding rock and the anchoring length L2 of the second anchoring section 112-2 need to be ensured to meet the requirement.
The construction method of the soil-rock double-element foundation pit combined type support pile in the embodiment specifically comprises the following steps:
1) trial calculation is carried out on the safety coefficient K of the overall stability of the side wall of the foundation pit, whether the reinforcing bars 112-5 of the miniature piles 112 are safe and reasonable is calculated through checking, and the reinforcing bars 112-5 are adjusted according to the safety coefficient of the overall stability; if the K value is smaller than the required safety factor, the preset shearing strength of the micro-piles 112 is insufficient, and the number of the micro-piles 112 or reinforcing bars 112-5 are increased; if the K value is far greater than the required safety factor, the preset shearing strength of the micro-piles 112 is over conservative, so that the number of the micro-piles 112 can be reduced or the reinforcing bars 112-5 can be reduced;
in this embodiment, the overall stability safety coefficient K is calculated by trial using the following formula (4):
K=Mk/Mq...........................................（4）；
in the formula:
Mk=∑cikli+∑(q0bi+wi)cosθitgϕik+2kγsTA/b；
Mq=∑(q0bi+wi)sinθi；
in the formula, K is the integral stability safety coefficient; the safety grades are a first-grade foundation pit, a second-grade foundation pit and a third-grade foundation pit respectively, and the corresponding overall stability safety factors K are not less than 1.35, 1.3 and 1.25 respectively;
Mkthe anti-skid moment is generated by rock soil at a position 2-1 of a certain slip crack surface in the soil layer 2 and the combined type supporting pile;
Mqthe gliding moment is generated by rock soil and load above a certain sliding crack surface 2-1 in the soil layer 2;
cikobtaining data through geotechnical engineering investigation for consolidation non-drainage shear cohesion of soil on the ith soil strip 2-2 slip crack surface on a certain slip crack surface 2-1 in a soil layer 2;
ϕikobtaining data through geotechnical engineering investigation for the standard value of the internal friction angle of soil on the ith soil strip 2-2 slip crack surface on a certain slip crack surface 2-1 in the soil layer 2;
bitaking a value for the width of the ith soil strip 2-2 by a designer according to experience;
liis the slip surface length of the ith soil strip 2-2, li=bi/cosθi；
wiCalculating the weight of the ith soil strip 2-2 acting on the slip crack surface 2-1 according to the weight of the natural soil of the overlying soil layer, obtaining data through a geotechnical engineering investigation report, and accumulating each geotechnical layer;
θian included angle between the normal of the midpoint of the slip crack line segment of the ith soil strip 2-2 and the vertical plane;
q0in order to act on the load on the foundation pit surface, a designer takes values according to the field condition and the subsequent use condition;
γsa coefficient is developed for the shear strength of the micropile 112, which is an empirical coefficient or determined by experiment;
k is the number of the micro piles 112 arranged below each cast-in-place pile 111, and the design personnel set the number according to experience;
t is the shear strength standard value of the reinforcing bars of the single micro pile 112 at the sliding surface 2-1;
a is the cross-sectional area of a single micro pile reinforcement bar 112-5, and when the number of the reinforcement bars 112-5 is more, A is the accumulated cross-sectional area of the plurality of reinforcement bars 112-5;
b is the center distance between adjacent cast-in-place piles 111 in the first row of composite piles 100, that is, the center distance between adjacent cast-in-place piles 111 in the second row of composite piles 200;
the side wall of the foundation pit to be excavated is provided with a plurality of potential slip surfaces 2-1, the included angle phi between each slip surface 2-1 and the horizontal plane is different, and the weight w of the ith soil strip 2-2 on the slip surface 2-1 is acted by the different slip surfaces 2-1iIn contrast, the included angle theta between the normal of the midpoint of the corresponding slip crack line segment 2-2 of the ith soil strip and the vertical planeiAnd if the minimum value meets the design requirement, the whole stability and safety coefficient of the side wall of the foundation pit is stable. Taking a foundation pit with a first-level safety grade as an example, the corresponding overall stability safety coefficient K is not less than 1.35, and if the minimum K value in a plurality of overall stability safety coefficients K corresponding to a plurality of slip crack surfaces 2-1 is not less than 1.35, the requirement on the overall stability of the side wall of the foundation pit is met. The overall stability safety coefficient check calculation is respectively carried out by corresponding to the multiple potential slip crack surfaces 2-1, so that the reliability of the overall stability check calculation is greatly improved, and the safety of the foundation pit is ensured;
2) checking the anchoring length L1 of the first anchoring section and the anchoring length L2 of the second anchoring section of the micro-pile, and the anchoring length t below the embedded substrate;
the anchoring length L1 is checked by adopting the following formula (1), if the design value of the anchoring length L1 selected by checking does not meet the formula (1), other design values of L1 are selected and checked until the anchoring length L1 meeting the formula (1) is obtained:
L1≥Rk,j/(πDfd)...........................................（1）；
in the formula:
Rk,jobtaining a standard value of the ultimate uplift bearing capacity of the reinforcement bar 112-5 according to a corresponding material standard;
d is the inner diameter of a fixed steel pipe 111-4 serving as a drilling channel in the cast-in-place pile 111, and is an empirical value;
fdselecting or selecting a standard value of the bonding strength between the inner wall of the fixed steel pipe 111-4 in the cast-in-place pile 111 and a grouting material according to related standards or tests;
and (3) checking the anchoring length L2 by combining the anchoring length L1 which is obtained by the formula (1) and meets the formula (1), checking the anchoring length L2 by adopting the following formula (2), and if the design value of the anchoring length L2 selected by checking does not meet the formula (2), selecting other design values of the L2 and then checking until the formula (2) is met:
L1/L2≥Rk,j /(πξnrfb) ...................................（2）；
in the formula:
Rk,jobtaining a 112-5 limit uplift bearing capacity standard value for the reinforcing steel bars of the miniature pile according to a corresponding material standard;
r is the diameter of the grouting anchoring body of the cast-in-place pile 111 and is an empirical value;
fdselecting or selecting a standard value of the bonding strength between the inner wall of the fixed steel pipe 111-4 in the cast-in-place pile 111 and a grouting material according to related standards or tests;
n is 112-5 counts of reinforcing bars of the miniature piles, and is an empirical value;
xi is the reduction coefficient of the bonding strength, when the number of the reinforcing ribs 112-5 is 3, xi is 0.7, when the number of the reinforcing ribs 112-5 is 4, xi is 0.55;
in combination with the anchor length L2 satisfying the formula (2) obtained from the formula (2), the anchor length L2 is checked, and the anchor length t is checked using the following formula (3):
t/L2≥Rk,j /(πrqsik) ...........................................（3）；
in the formula:
Rk,jobtaining a 112-5 limit uplift bearing capacity standard value for the reinforcing steel bars of the miniature pile according to a corresponding material standard;
r is the diameter of the grouting anchoring body of the cast-in-place pile 111 and is an empirical value;
qsikthe bonding strength standard value of the grouting anchoring body for the micropile 112 in the rock stratum hard rock is determined according to the relationStandard selection or test selection;
since the L1 needs to satisfy the formula (1) and the formula (2) at the same time, and the L2 needs to satisfy the formula (2) and the formula (3) at the same time, the L1 and the L2 obtained by checking the formulas (1), (2) and (3) should take the larger value as the design value respectively; after the checking calculation is finished, the following construction steps are carried out;
3) constructing a pile hole of a cast-in-place pile 111, forming a final hole when a hard rock stratum 3-2 is formed, manufacturing a reinforcement cage 111-3 according to the depth of the pile hole, and welding and fixing fixed steel pipes 111-4 which correspond to the designed micro-piles 112 one by one on the inner side of the reinforcement cage 111-3 to be used as drilling channels;
4) plugging measures are taken at the bottom end and the top end of a fixed steel pipe 111-4 fixed in the reinforcement cage 111-3 to prevent concrete from pouring into the pipe, and anti-floating pressure or fixing measures of the reinforcement cage 111-3 are taken at the orifice of a pile hole;
5) cleaning cement soil and concrete at the top end of the cast-in-place pile 111, exposing the reinforcing steel bars of the cast-in-place pile 111 and the head of the fixed steel pipe 111-4, binding the reinforcing steel bars of the crown beam 300 and the connecting beam 400, pouring concrete, and forming the crown beam 300 and the connecting beam 400;
6) drilling a micro pile 112 by taking a fixed steel pipe 111-4 fixed in the reinforcement cage 111-3 as a drilling channel;
7) installing a micro pile core, namely a positioning support 112-4, a reinforcing bar 112-5 and a short reinforcing bar 112-6 into a hole, pouring cement mortar or pure cement slurry into the micro pile 112 and the fixed steel pipe 111-4, and anchoring the micro pile 112 and the poured pile 111 into a whole;
8) the foundation pit is layered, and a protective surface layer 600 is constructed in layers.
Further, when a step of constructing cement-soil piles 500 between adjacent cast-in-place piles 111 of the first row of composite piles 100 is further provided between step 4) and step 5), a waterproof curtain is formed together with the cast-in-place piles 111.
And 8) constructing the side protective surface layer 600 of the foundation pit excavation in the step 8), wherein the concrete is sprayed by using a hanging net, the diameter of a net rib is 4-8mm, the diameter of a grid is 200-300mm, the mark of the sprayed concrete is C20, and the thickness is 60-100 mm.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions.
Claims (8)
1. The utility model provides a two first foundation ditch combination formula fender piles of soil rock which characterized in that: the combined piles of the first row and the second row are connected into a whole by a crown beam and a coupling beam; the first row of composite piles comprise a plurality of composite piles arranged along the side wall of the foundation pit at intervals, each composite pile comprises a cast-in-place pile and a plurality of miniature piles located below the cast-in-place pile, the cast-in-place piles are located in the soil layer, the bottom ends of the cast-in-place piles are embedded into upper soft rock of the rock layer, the miniature piles are located in the rock layer, each miniature pile comprises a first anchoring section and a second anchoring section, the second anchoring section is located below the first anchoring section and located in lower hard rock of the rock layer, and the first anchoring section is embedded into and anchored in the cast-in-place piles.
2. The soil-rock double-foundation-pit combined type support pile according to claim 1, characterized in that:
bored concrete pile including cast-in-place concrete, steel reinforcement cage and with the fixed steel pipe of miniature stake one-to-one, fixed steel pipe runs through the top and the bottom of bored concrete pile, be equipped with a plurality of fixed steel bars that set up along its axial interval on the fixed steel pipe, fixed steel bar with steel reinforcement cage welding is as an organic whole and hoop establishes on the fixed steel pipe.
3. The soil-rock double-foundation-pit combined type support pile according to claim 2, characterized in that:
the inner diameter of the fixed steel pipe is 146-219mm, the wall thickness is 3-5mm, and the diameter of the micro pile is 15-25mm smaller than the inner diameter of the fixed steel pipe.
4. The soil-rock double-foundation-pit combined type support pile according to claim 1, characterized in that:
and the combined piles of the first row of combined piles and the combined piles of the second row of combined piles are aligned one by one.
5. The soil-rock double-foundation-pit combined type support pile according to claim 1, characterized in that:
and cement-soil piles are arranged between adjacent cast-in-place piles of the first row of composite piles.
6. A construction method of the soil-rock double-foundation-pit combined type support pile as claimed in any one of claims 1 to 5, characterized by comprising the following steps:
1) setting the whole stability safety coefficient trial calculation of the combined support piles for the foundation pit, checking whether the reinforcement of the miniature pile is safe and reasonable or not, and adjusting the reinforcement of the miniature pile according to the whole stability safety coefficient;
the overall stability safety coefficient is calculated by trial by adopting the following formula (4):
K=Mk/Mq...........................................（4）；
in the formula:
Mk=∑cikli+∑(q0bi+wi)cosθitgϕik+2kγsTA/b;
Mq=∑(q0bi+wi)sinθi;
in the formula, K is the integral stability safety coefficient; the safety grades are a first-grade foundation pit, a second-grade foundation pit and a third-grade foundation pit respectively, and the corresponding overall stability safety factors are not less than 1.35, 1.3 and 1.25 respectively;
Mkthe anti-skid moment is generated for rock and soil at a certain slip crack surface and the combined type supporting pile;
Mqthe gliding moment is generated by rock soil and load above a certain sliding crack surface;
cikfor the i-th soil strip on a certain slip crack surfaceSolidifying soil on the crack surface without draining water, shearing and aggregating force, and obtaining data through geotechnical engineering investigation;
ϕikobtaining data for the standard value of the internal friction angle of soil on the ith soil strip slip surface on a certain slip surface through geotechnical engineering investigation;
bitaking a value for the width of the ith soil strip by a designer according to experience;
liis the slip surface length of the ith soil strip, li=bi/cosθi；
wiCalculating the weight of the ith soil strip acting on the slip crack surface according to the weight of the natural soil of the overlying soil layer, and acquiring data through a geotechnical engineering investigation report, wherein each geotechnical layer is accumulated;
θian included angle between the normal of the midpoint of the slip crack line segment of the ith soil strip and the vertical plane;
q0in order to act on the load on the foundation pit surface, a designer takes values according to the field condition and the subsequent use condition;
γsthe coefficient is used for exerting the shear strength of the micro pile, and is an empirical coefficient or is determined through experiments;
k is the number of the micro piles arranged below each cast-in-place pile, and the number is set by a designer according to experience;
t is a shear strength standard value of the reinforcing bars of the single miniature pile at the sliding surface;
a is the cross-sectional area of the reinforcing bars of a single miniature pile, and when a plurality of reinforcing bars are arranged, A is the accumulated cross-sectional area of the plurality of reinforcing bars;
b is the center distance of adjacent cast-in-place piles in the first row of composite piles and the second row of composite piles;
performing overall stability safety coefficient trial calculation respectively by arranging a plurality of slip fracture surfaces and different micro pile reinforcing bars to obtain a plurality of overall stability safety coefficients, and if the minimum value meets the design requirement, integrally stabilizing the side wall of the foundation pit and determining the corresponding micro pile reinforcing bars;
2) checking the anchoring length L1 of the first anchoring section and the anchoring length L2 of the second anchoring section of the micro-pile, and the anchoring length t below the embedded substrate;
wherein, the anchoring length L1 is checked by adopting the following formula (1), if the anchoring length L1 does not satisfy the formula (1), the L1 is adjusted until the formula (1) is satisfied:
L1≥Rk,j/(πDfd)...........................................（1）；
in the formula:
Rk,jobtaining a standard value of ultimate uplift bearing capacity of reinforcing bars for the miniature pile according to a corresponding material standard;
d is the inner diameter of a fixed steel pipe serving as a drilling channel in the cast-in-place pile, and is an empirical value;
fdselecting or selecting a standard value of the bonding strength between the inner wall of the fixed steel pipe in the cast-in-place pile and a grouting material according to related standards or tests;
the anchoring length L2 is checked by adopting the following formula (2), and if the anchoring length L2 does not satisfy the formula (2), L2 is adjusted until the formula (2) is satisfied:
L1/L2≥Rk,j /(πξnrfb) ...........................................（2）；
in the formula:
Rk,jobtaining a standard value of ultimate uplift bearing capacity of reinforcing bars for the miniature pile according to a corresponding material standard;
r is the diameter of the grouting anchoring body of the cast-in-place pile, and is an empirical value;
fdselecting or selecting a standard value of the bonding strength between the inner wall of the fixed steel pipe in the cast-in-place pile and a grouting material according to related standards or tests;
n is the reinforcement count of the micro pile and is an empirical value;
xi is the reduction coefficient of the bonding strength, when the number of the reinforcing bars of the miniature pile is 3, xi is 0.7, and when the number of the reinforcing bars of the miniature pile is 4, xi is 0.55;
the anchoring length t is calculated by adopting the following formula (3):
t/L2≥Rk,j /(πrqsik) ...........................................（3）；
in the formula:
Rk,jobtaining a standard value of ultimate uplift bearing capacity of reinforcing bars for the miniature pile according to a corresponding material standard;
r is the diameter of the grouting anchoring body of the cast-in-place pile, and is an empirical value;
qsikselecting or selecting a bonding strength standard value of the micro pile grouting anchoring body in the hard rock of the rock stratum according to related standards or tests;
taking the larger value of L1 and L2 obtained by checking the formulas (1), (2) and (3) as the design value;
3) constructing pile holes of a cast-in-place pile, forming final holes when the holes reach rock stratum hard rock, manufacturing a reinforcement cage according to the depth of the pile holes, and welding and fixing fixed steel pipes which correspond to the designed micro piles one by one on the inner side of the reinforcement cage to be used as drilling channels;
4) plugging measures are taken at the bottom end and the top end of a fixed steel pipe fixed in the steel reinforcement cage to prevent poured concrete from entering the fixed steel pipe, and anti-floating pressure or fixing measures of the steel reinforcement cage and the fixed steel pipe are taken at the orifice of a pile hole;
5) cleaning cement soil and concrete at the top end of the cast-in-place pile, exposing the steel bars of the cast-in-place pile and the head of the fixed steel pipe, binding the crown beam and the connecting beam steel bars, pouring concrete, and forming the crown beam and the connecting beam;
6) drilling the miniature pile by taking a fixed steel pipe fixed in the reinforcement cage as a drilling channel;
7) placing a pile core of the micro pile, pouring cement mortar or pure cement slurry into the micro pile and the fixed steel pipe, and anchoring the micro pile and the poured pile into a whole;
8) and excavating the side of the foundation pit in layers, and constructing a protective surface layer in layers.
7. The construction method according to claim 6,
and a step of constructing a waterproof curtain on the inner side of the cast-in-place pile of the first row of combined piles is also arranged between the step 4) and the step 5).
8. The construction method according to claim 6,
and 8) constructing the side protective surface layer of the foundation pit excavation in the step 8) by adopting a hanging net to spray concrete, wherein the diameter of a net rib is 4-8mm, the diameter of a grid is 200-300mm, the label of the sprayed concrete is C20, and the thickness is 60-100 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110241419.6A CN113026760A (en) | 2021-03-04 | 2021-03-04 | Combined type supporting pile for double-element foundation pit of soil and rock and construction method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110241419.6A CN113026760A (en) | 2021-03-04 | 2021-03-04 | Combined type supporting pile for double-element foundation pit of soil and rock and construction method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113026760A true CN113026760A (en) | 2021-06-25 |
Family
ID=76467700
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110241419.6A Pending CN113026760A (en) | 2021-03-04 | 2021-03-04 | Combined type supporting pile for double-element foundation pit of soil and rock and construction method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113026760A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114439015A (en) * | 2022-02-28 | 2022-05-06 | 中国建筑第五工程局有限公司 | Construction method for improving rock-socketed depth of large-diameter cast-in-place pile |
| CN114482071A (en) * | 2022-02-28 | 2022-05-13 | 中国建筑第五工程局有限公司 | Device for improving rock-socketed depth of large-diameter cast-in-place pile |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101122131A (en) * | 2007-08-14 | 2008-02-13 | 蓝冰 | Foundation pit supporting pile using pipe casting pile embedding in rock |
| CN203625893U (en) * | 2013-12-23 | 2014-06-04 | 青岛业高建设工程有限公司 | Rock-embedded cast-in-place pile |
| US20140255106A1 (en) * | 2013-03-07 | 2014-09-11 | Allan P. Henderson | Perimeter pile anchor foundation |
| CN109457709A (en) * | 2018-12-26 | 2019-03-12 | 青岛业高建设工程有限公司李沧分公司 | A kind of supporting construction and construction method of double-row pile combination wide-angle anchor cable |
| CN209339156U (en) * | 2018-12-04 | 2019-09-03 | 中铁十二局集团第二工程有限公司 | The embedding rock foot pilework of anchor tube formula in a kind of Extra-Deep Foundation Pit |
| CN110924433A (en) * | 2019-12-09 | 2020-03-27 | 中交铁道设计研究总院有限公司 | Design method of subway foundation pit foot-hanging pile enclosure structure in upper-soft lower-hard rock stratum |
-
2021
- 2021-03-04 CN CN202110241419.6A patent/CN113026760A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101122131A (en) * | 2007-08-14 | 2008-02-13 | 蓝冰 | Foundation pit supporting pile using pipe casting pile embedding in rock |
| US20140255106A1 (en) * | 2013-03-07 | 2014-09-11 | Allan P. Henderson | Perimeter pile anchor foundation |
| CN203625893U (en) * | 2013-12-23 | 2014-06-04 | 青岛业高建设工程有限公司 | Rock-embedded cast-in-place pile |
| CN209339156U (en) * | 2018-12-04 | 2019-09-03 | 中铁十二局集团第二工程有限公司 | The embedding rock foot pilework of anchor tube formula in a kind of Extra-Deep Foundation Pit |
| CN109457709A (en) * | 2018-12-26 | 2019-03-12 | 青岛业高建设工程有限公司李沧分公司 | A kind of supporting construction and construction method of double-row pile combination wide-angle anchor cable |
| CN110924433A (en) * | 2019-12-09 | 2020-03-27 | 中交铁道设计研究总院有限公司 | Design method of subway foundation pit foot-hanging pile enclosure structure in upper-soft lower-hard rock stratum |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114439015A (en) * | 2022-02-28 | 2022-05-06 | 中国建筑第五工程局有限公司 | Construction method for improving rock-socketed depth of large-diameter cast-in-place pile |
| CN114482071A (en) * | 2022-02-28 | 2022-05-13 | 中国建筑第五工程局有限公司 | Device for improving rock-socketed depth of large-diameter cast-in-place pile |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100567659C (en) | The base configuration of iron tower | |
| JP6279945B2 (en) | Soil surface anti-slip method for earth structure | |
| CN108343071A (en) | A kind of foundation pit supporting construction and construction method of steel sheet pile combined deposited pile | |
| CN113026760A (en) | Combined type supporting pile for double-element foundation pit of soil and rock and construction method thereof | |
| CN107100179B (en) | Light combined retaining structure and method for treating large-range high-fill slope engineering | |
| JP6370645B2 (en) | Slope stabilization method for seismic and rainproof measures of earth structures by using pressure injection type rod-shaped reinforcements | |
| CN206902783U (en) | For reducing the adjustable reinforcement and rectification structure of house differential settlement | |
| KR20120102480A (en) | Phc pile with improved end bearing capacity and piling method of phc pile using the same | |
| CN210263075U (en) | Arrange bars formula tubular pile post back slip casting internal anchor outer stagnant water support system | |
| CN205576957U (en) | Stake end pilework | |
| CN209779642U (en) | Miniature pile with antiskid structure and retaining wall assembly thereof | |
| CN110889235A (en) | Underground pile foundation construction engineering design method | |
| CN216787094U (en) | Real-time active servo steel underground diaphragm wall construction method pile | |
| WO2023131936A2 (en) | Bioinspired skirted footing and its method of installation | |
| CN114439015A (en) | Construction method for improving rock-socketed depth of large-diameter cast-in-place pile | |
| CN115717397A (en) | Larsen steel sheet pile and prestressed anchor cable combined supporting construction method | |
| CN216239904U (en) | Existing building underpins and consolidates connection structure | |
| CN215715241U (en) | Novel post-tensioned prestressing rectangular cast-in-place pile | |
| CN214301763U (en) | Green supporting construction that interim excavation supporting and permanent side slope support combined together | |
| CN209324377U (en) | Ledge method tunneling subway station arch springing ruggedized construction | |
| CN201232189Y (en) | Composite soil nail wall supporting construction for adding piers | |
| CN113684835A (en) | Foundation pit supporting and water stopping system and construction process | |
| CN208023591U (en) | A kind of foundation pit supporting construction of steel sheet pile combined deposited pile | |
| CN113026761B (en) | Soil-rock double-element foundation pit composite supporting structure and construction method thereof | |
| CN105951743A (en) | Plum blossom-shaped profile steel cement stirring wall |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210625 |
|
| RJ01 | Rejection of invention patent application after publication |