Method for detecting, evaluating and processing pile-forming defects of casing secant pile in reclamation area

Abstract

The invention discloses a method for detecting, evaluating and processing pile-forming defects of casing secant piles in a reclamation area. The method comprises the following steps: S1, calculating a deviation value and a secant amount; s2, forming evaluation indexes; and S3, the jet grouting piles are additionally arranged according to the evaluation indexes. According to the method, the bite quantity deviation of the max (the excavation depth of the foundation pit and 3m below the elevation of the water-resisting layer) position is taken as a main evaluation index, the bite quantity deviation of the top of the foundation pit is taken as a secondary evaluation index, and the perpendicularity is taken as an auxiliary evaluation index; the high-pressure jet grouting piles are additionally arranged on the outer sides of the casing secant piles, so that the defect positions of the casing secant piles can be supplemented, the water leakage possibility at the joints is reduced, and the water stopping effect of an enclosure structure is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underground engineering construction. BACKGROUND

[0002] The underground structure is in the underground, and is easily affected by main factors such as stratum soil properties and underground water. Artificial reclamation areas are generally formed by artificial filling on the original stratum of the sea area, and the stratum structure stability of artificial islands is poor. The underground water and seawater are closely related in hydraulic connection. The stratum of the artificial reclamation area is generally composed of miscellaneous filling layer, backfill layer, undisturbed soil surface layer (permeable water layer) and undisturbed stratum (water-resisting layer) from top to bottom. The deep foundation pit support is generally composed of a support structure and a water stopping measure, and the support structure with a closed form can also serve as a water stopping measure. Due to the high porosity of the backfilling block stone layer in the artificial reclamation area, and the influence of tides, the deep foundation pit support pile (wall) hole (slot) is prone to serious slurry leakage, which causes the hole (slot) to collapse. The over-diameter phenomenon of the backfilling quarry stone is serious, and a large amount of boulders with high strength are contained. The construction efficiency of the support pile (wall) is low, and the support pile (wall) is prone to tilting when encountering large stones, thereby causing water leakage of the deep foundation pit support structure and affecting the construction safety.

[0003] At present, the common types of deep foundation pit support structures in artificial reclamation areas include cast-in-situ bored piles, interlocking piles (including sleeve interlocking piles) and underground continuous walls. The interlocking pile is a kind of foundation pit support structure in which piles are arranged in interlocking mode. The interlocking pile is a kind of whole continuous waterproof and soil retaining support structure with good anti-seepage effect, which is formed by embedding a steel reinforcement cage into the pile in the subsequent interlocking construction. The piles are arranged in a mode in which an un-reinforced super-delayed setting concrete pile (plain pile) and a reinforced concrete pile (meat pile) are arranged at intervals by using a full casing drilling machine. During the construction of the interlocking pile, the A pile is constructed first, and then the B pile is constructed. The B pile construction is completed before the initial setting of the A pile concrete.

[0004] The existing cast-in-situ bored piles, interlocking piles (including sleeve interlocking piles) and underground continuous walls generally use a total station, a GPS and a ruler to measure the ground deviation before the hole (slot) forming process. In the construction process, artificial measurement and sensors on the equipment can be used for rough hole (slot) verticality detection. However, the defects of the sleeve interlocking pile cannot be supplemented, water leakage easily occurs at the joint, and the water stopping effect of the support structure is poor. SUMMARY

[0005] In order to solve the above problems existing in the existing interlocking pile defect detection technology in the reclamation area, the present application provides a reclamation area interlocking pile defect detection evaluation and treatment method.

[0006] The technical scheme adopted by the present application to achieve the above object is as follows: a method for detecting and evaluating and processing pile forming defects of a reclamation area sleeve bite pile, comprising the following steps:

[0007] S1: calculating deviation values and bite amounts, detecting the verticality of each pile before pouring concrete after drilling the reclamation area sleeve bite pile, obtaining the horizontal actual pile forming position deviation of the top position of the raw pile (1) and the cooked pile (2), the bottom position of the raw pile (1), and the bottom position of the cooked pile (2), and calculating the bite amount of each position in the horizontal direction of the adjacent two sleeve bite piles;

[0008] S2: forming evaluation indexes, obtaining a multi-dimensional evaluation matrix with the bite amount at the position 3m below the bottom depth of the foundation pit / water-resisting layer elevation in the horizontal direction as the main evaluation index, the bite amount at the top of the foundation pit as the secondary evaluation index, and the verticality as the auxiliary evaluation index;

[0009] S3: adding a rotary jet pile according to the evaluation indexes.

[0010] In the step S1,

[0011] the verticality of the raw pile (1) is recorded, the plane deviation of the top position of the cooked pile (2) and the bottom position of the raw pile (1) is calculated, P1 is the longitudinal deviation in the pile horizontal plane, P2 is the transverse deviation in the pile horizontal plane, the pile positioning deviation is the deviation that can be directly measured at the ground position of the pile, W1 is the longitudinal deviation of the cooked pile positioning horizontal, W2 is the transverse deviation of the cooked pile positioning horizontal, W3 is the longitudinal deviation of the raw pile positioning horizontal, and W4 is the transverse deviation of the raw pile positioning horizontal,

[0012] the verticality detection deviation, i.e., the slope K, is directly calculated by the ultrasonic detection, i.e., the deviation value detected by the ultrasonic detection at the pile bottom or a certain depth position ÷ the depth, K1 is the longitudinal slope, and K2 is the transverse slope;

[0013] the actual bite amount X of the adjacent two cooked and raw piles at the ground position is X=R1+R2-(Q-deviation)=R1+R2-(Q-[(Q+W1-W3) 2 +(W2-W4) 2 ] 0 . 5 .

[0014] X bite amount=the actual bite amount X of the cooked and raw piles in the adjacent two piles at the position max (the excavation depth of the foundation pit, 3m below the water-resisting layer elevation) X=R1+R2-(Q-deviation)=R1+R2-(Q-[(Q+W1-W3) 2 +(W2-W4) 2 ] 0 . 5

[0015] max (depth of foundation pit excavation, 3m below the water-resisting layer elevation) position refers to: taking the greater value of the depth of foundation pit excavation, 3m below the water-resisting layer elevation, i.e.max [S1, (H1+H2+H3+3)],

[0016] verticality design limit, KO,

[0017] X0 design standard bite = R1+R2-Q0,

[0018] R1 is the radius of the concrete pile, R2 is the radius of the cast-in-place pile, and Q is the center distance between the concrete pile and the cast-in-place pile.

[0019] The multi-dimensional evaluation matrix in the step S2 is:

[0020]

[0021]

[0022] In the step S3, the method for adding a rotary jet grouting pile is:

[0023]

[0024] In the step S3, the method for adding a rotary jet grouting pile is:

[0025] A high-pressure rotary jet grouting pile is arranged with the bite amount at the position 3m below the water-resisting layer elevation as the central axis, and one high-pressure rotary jet grouting pile is arranged on each side,

[0026] If one high-pressure rotary jet grouting pile is added according to the verticality adjustment, the sleeve bite pile position arranged in the pile top plane farthest from the central axis,

[0027] To improve the implementability of engineering design and construction, a simplified algorithm is performed:

[0028] The bite amount of the added rotary jet grouting pile = {0.5R-100- [R / 6-100]} rounded to the nearest integer with 50,

[0029] The bite amount of the two rotary jet grouting piles with different radii = {0.25(R1+R2)-100- [(R1+R2) / 12-100]} rounded to the nearest integer with 50,

[0030] The bite amount of the rotary jet grouting pile and the sleeve bite pile is calculated based on the diameter of the rotary jet grouting pile,

[0031] When one high-pressure rotary jet grouting pile is added, the bite amount at the vertical line of the position with a depth of 2 / 3*(H3+3) is the center of the high-pressure rotary jet grouting pile, and the distance P between the center of the high-pressure rotary jet grouting pile and the bite amount connecting line is the radius R+actual bite amount, i.e.R+1.5X, when X is less than 0, 0 is taken;

[0032] When the number of high-pressure rotary jet piles is increased to n, 1 is taken as the above setting; the remaining n-1 are symmetrically arranged, and the symmetry axis is the midline of the occlusion amount at a depth of 0.5*(H3+3).

[0033] The reclamation area sleeve bite pile forming defect detection evaluation and processing method of the application takes the occlusion amount deviation at the position of max (foundation pit excavation depth, 3m below the water-resisting layer elevation) as the main evaluation index, takes the occlusion amount deviation at the top of the foundation pit as the secondary evaluation index, and takes the verticality as the auxiliary evaluation index; by adding high-pressure rotary jet piles outside the sleeve bite pile, defects in the sleeve bite pile can be supplemented, the possibility of water leakage at the joint can be reduced, and the water stopping effect of the enclosure structure can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a plan view of the sleeve bite pile.

[0035] Figure 2 It is a cross-sectional view of the reclamation stratum, deep foundation pit and sleeve bite pile.

[0036] Figure 3 It is a plan view of the added high-pressure rotary jet pile.

[0037] In the figure:

[0038] 1, plain pile, 2, meat pile, 3, high-pressure rotary jet pile;

[0039] (1) D, stratum, D1, miscellaneous fill layer, D2, backfill layer, D3, undisturbed soil surface layer (permeable water layer), D4, undisturbed stratum (water-resisting layer));

[0040] (2) H, stratum thickness, H1, miscellaneous fill layer thickness, H2, backfill layer thickness, H3, undisturbed sand layer (permeable water layer) thickness, H4, undisturbed clay stratum (water-resisting layer) thickness);

[0041] (3) L, pile length, L1, meat pile length, L2, plain pile length;

[0042] (4) S1, foundation pit excavation depth;

[0043] (5) Verticality deviation i. DETAILED DESCRIPTION

[0044] In the reclamation area, the artificial reclamation stratum is generally block stone particle reclamation. The block stone particle reclamation has large particle size, high void ratio and large permeability coefficient, and it is prone to have difficulty in controlling the verticality when constructing the deep foundation pit enclosure structure. Before pouring concrete after the sleeve bite pile is formed, the ultrasonic instrument is used for deviation and verticality detection, and the pile top position, plain pile 1 pile bottom position and meat pile 2 pile bottom position are detected.

[0045] Assumptions:

[0046] (1) Assume that the foundation pit is rectangular, and that the top elevation of all piles (both solid and plain) is the same, with the top of the pile being the ground elevation.

[0047] (2) Further assume that the direction with the longer excavation length is the longitudinal direction of the excavation pit, and the direction with the shorter excavation length is the transverse direction of the excavation pit;

[0048] (3) Assume that the pile is a perfect circle with the same diameter as the design diameter and there is no reduction in diameter;

[0049] (4) Ultrasonic testing is performed in two directions: transverse and longitudinal, and is parallel to the longitudinal and transverse directions of the foundation pit, respectively.

[0050] (5) Assume that in the longitudinal direction of the foundation pit, eastward is the positive direction and the deviation is taken as a positive value; westward is the negative direction and the deviation is taken as a negative value;

[0051] (6) Assume that in the horizontal direction of the foundation pit, the northward direction is positive and the deviation is taken as a positive value; the southward direction is negative and the deviation is taken as a negative value;

[0052] (7) Assuming that the land reclamation strata are prone to collapse, in the construction of the casing interlocking pile, the plain pile is constructed by using casing to follow through the thickness of H1 miscellaneous fill layer, H2 backfill layer, H3 original sand layer (permeable water layer) to H4 original clay rock strata (water-proof layer).

[0053] like Figure 1 and Figure 2 As shown, by means of ultrasonic testing, the verticality of each pile is tested after drilling and before concrete is poured in the casing interlocking pile in the reclamation area. The deviation of the actual horizontal pile position from the design standard value at the top position of plain pile 1 and pile 2, the bottom position of plain pile, and the bottom position of pile 3 is calculated.

[0054] First, record the verticality of the first pile (plain pile). Calculate the two positional deviations of the pile top and the pile bottom. P1 is the longitudinal deviation in the horizontal plane of the pile, and P2 is the lateral deviation in the horizontal plane of the pile.

[0055] Pile positioning deviation is the deviation of the pile's position on the ground that can be directly measured. W1 is the horizontal longitudinal deviation of the pile positioning, and W2 is the horizontal lateral deviation of the pile positioning.

[0056] W3 is the horizontal longitudinal deviation of the plain pile positioning, and W4 is the horizontal lateral deviation of the plain pile positioning.

[0057] The verticality detection deviation, i.e., the slope K, can be directly calculated from ultrasonic testing. It is the deviation value detected by ultrasonic testing at the bottom of the pile or at a certain depth ÷ the depth, where K1 is the longitudinal slope and K2 is the transverse slope.

[0058] Verticality design limitations, KO.

[0059] X0 design standard bite amount = R1 + R2 - Q0.

[0060] R1 is the radius of the solid pile, and R2 is the radius of the plain pile.

[0061] Q: Center-to-center distance between meat and vegetable piles.

[0062] The actual interlocking amount X between two adjacent animal and plant stakes on the ground is calculated as follows: X = R1 + R2 - (Q - deviation) = R1 + R2 - (Q - [(Q + W1 - W3)] 2 +(W2-W4) 2 ] 0.5 .

[0063] X_interlocking amount = Actual interlocking amount of the two adjacent piles (one for meat and one for vegetables) at a position 3m below the water-resistant layer elevation. X = R1 + R2 - (Q - deviation) = R1 + R2 - (Q - [(Q + W1 - W3)] 2 +(W2-W4) 2 ] 0.5 .

[0064] Evaluation Indicator Principles:

[0065] (1) The main evaluation index is the deviation of the interlocking amount at the position of max (excavation depth of the foundation pit, 3m below the elevation of the water-resistant layer);

[0066] (2) The deviation of the interlocking amount at the top of the foundation pit is used as a secondary evaluation indicator;

[0067] (3) Verticality is used as an auxiliary evaluation index (when the inclination of both cast-in-place piles exceeds the specifications and design requirements, one jet grouting pile is added).

[0068] According to the proposed defect evaluation algorithm, the preferred options are: (1) when the interlocking amount at the max (excavation depth of the foundation pit, 3m below the elevation of the impermeable layer) position is not less than 70% of the design standard and the interlocking amount at the pile top position is not less than 70% of the design standard, it is judged as qualified; (2) when the interlocking amount at the pile top position is not less than 30% of the design standard and the interlocking amount at the max (excavation depth of the foundation pit, 3m below the elevation of the impermeable layer) position is not less than 30% of the design standard (excluding the qualified case 1), it is judged as a first-level defect; (3) a second-level defect; (4) a third-level defect.

[0069] Defect evaluation index algorithm:

[0070]

[0071]

[0072] When the verticality of two adjacent cast-in-place piles both exceeds the specifications and design requirements, the defect level is increased by one level.

[0073] like Figure 3As shown, high-pressure jet grouting piles are added to the outside of the casing interlocking pile according to the defect level. One jet grouting pile is added for a first-level defect, three jet grouting piles are added for a second-level defect, and four jet grouting piles are added for a third-level defect.

[0074]

[0075] Based on the actual pile position deviation and defect evaluation level of the interlocking piles, and the algorithm for the layout of additional high-pressure jet grouting piles based on the actual pile position, the specific layout position of each high-pressure jet grouting pile is calculated to achieve the best water-stopping effect.

[0076] Jet grouting pile layout principles:

[0077] The optimal algorithm is based on the diameter of the interlocking piles and the number of additional jet grouting piles. Factors to consider include:

[0078] (1) The actual position after the deviation of the interlocking pile at a position 3m below the elevation of the water-tight layer is mainly considered;

[0079] (2) The actual position of the pile top after the deviation of the interlocking pile;

[0080] (3) Quantity is determined based on the position of the top of the two adjacent piles and the position 3m below the elevation of the waterproof layer.

[0081] Jet Grouting Pile Layout Details

[0082] Using the center line of the symmetrical interlocking amount at a position 3m below the watertight layer elevation as the central axis, a high-pressure jet grouting pile (diameter of 800mm) is set, and one high-pressure jet grouting pile is set on each side in sequence.

[0083] If one high-pressure jet grouting pipe is added to adjust the verticality, it will be placed at the position of the sleeve interlocking pile furthest from the central axis in the plane of the pile top.

[0084] To improve the feasibility of engineering design and construction, a simplified algorithm is implemented:

[0085] The interlocking amount of the added jet grouting pile foundation = rounded to the nearest integer (0.5R - 100 - rounded to the nearest integer (R / 6 - 100))

[0086] The interlocking amount of two jet grouting piles with different radii = {0.25(R1+R2)-100-[(R1+R2) / 12-100] (rounded to the nearest integer)}

[0087] The amount of engagement between jet grouting piles and casing-engaged piles is calculated based on the diameter of the jet grouting pile.

[0088] When adding one high-pressure jet grouting pile, the vertical line where the bite amount is located at the depth of 2 / 3*(H3+3) is taken as the center of the high-pressure jet grouting pile. The distance P between the center of the high-pressure jet grouting pile and the line connecting the bite amount is the radius R + the actual bite amount, i.e., R + 1.5X. Note: When X is less than 0, take 0.

[0089] When n high-pressure jet grouting piles are added, one pile is set as described above; the remaining n-1 piles are arranged symmetrically, with the axis of symmetry being the centerline of the bite amount at a depth of 0.5*(H3+3).

[0090] This invention has been described through embodiments. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this invention.

Claims

1. A method for detecting, evaluating, and treating defects in casing-interlocking piles in reclaimed areas, characterized in that: Includes the following steps: S1: Calculate the deviation value and the amount of interlocking. After drilling the casing interlocking piles in the reclamation area and before pouring concrete, the verticality of each pile is checked. The deviation of the actual horizontal pile position of the plain pile (1) and the virgin pile (2), the bottom position of the plain pile (1), and the bottom position of the virgin pile (2) from the design standard value is obtained. The amount of interlocking in the horizontal direction of each position of the two adjacent casing interlocking piles is calculated. S2: Form an evaluation index, with the horizontal interlocking amount at a position 3m below the bottom depth of the foundation pit / the elevation of the waterproof layer as the main evaluation index, the interlocking amount at the top of the foundation pit as the secondary evaluation index, and verticality as the auxiliary evaluation index to obtain a multi-dimensional evaluation matrix. S3: Add jet grouting piles according to the evaluation indicators.

2. The method for detecting, evaluating, and treating defects in casing-interlocking piles in reclaimed areas according to claim 1, characterized in that: In step S1 Record the verticality of the plain pile (1), calculate the planar deviations of the top position of the solid pile (2) and the bottom position of the plain pile (1), P1 is the longitudinal deviation in the horizontal plane of the pile, P2 is the lateral deviation in the horizontal plane of the pile, the pile positioning deviation is the deviation that can be directly measured in the position of the pile on the ground, W1 is the longitudinal horizontal deviation of the solid pile positioning, W2 is the lateral horizontal deviation of the solid pile positioning, W3 is the longitudinal horizontal deviation of the plain pile positioning, and W4 is the lateral horizontal deviation of the plain pile positioning. Verticality detection deviation, i.e., slope K, is directly calculated from ultrasonic testing. It is the deviation value detected by ultrasonic testing at the bottom of the pile or at a certain depth ÷ depth. K1 is the longitudinal slope, and K2 is the transverse slope. The actual interlocking amount X between two adjacent animal and plant stakes on the ground is calculated as follows: X = R1 + R2 - (Q - deviation) = R1 + R2 - (Q - [(Q + W1 - W3)] 2 +(W2-W4) 2 ] 0 . 5 . X_interlocking amount = Actual interlocking amount of the two adjacent piles (both solid and solid) at the max position (excavation depth of the foundation pit, 3m below the elevation of the impermeable layer) X = R1 + R2 - (Q - deviation) = R1 + R2 - (Q - [(Q + W1 - W3)] 2 +(W2-W4) 2 ] 0 . 5 The position of max(excavation depth of the foundation pit, 3m below the elevation of the impermeable layer) refers to the larger of the two depths, i.e., max[S1, (H1+H2+H3+3)], hereinafter the same. Verticality design limitations, KO. X0 design standard bite amount = R1 + R2 - Q0, R1 is the radius of the non-metallic pile, R2 is the radius of the plain pile, and Q is the center-to-center distance between the non-metallic and plain piles.

3. The method for detecting, evaluating, and treating defects in casing-interlocking piles in reclaimed areas according to claim 1, characterized in that: The multi-dimensional evaluation matrix in step S2 is as follows:

4. The method for detecting, evaluating, and treating defects in casing-interlocking piles in reclaimed areas according to claim 1, characterized in that: In step S3, the method for adding jet grouting piles is as follows:

5. The method for detecting, evaluating, and treating defects in casing interlocking piles in reclaimed areas according to claim 4, characterized in that: In step S3, the method for adding jet grouting piles is as follows: Using the center line of the symmetrical interlocking amount at a position 3m below the elevation of the impermeable layer as the central axis, a high-pressure jet grouting pile is installed, with one high-pressure jet grouting pile installed on each side in sequence. If one high-pressure jet grouting pipe is added to adjust for verticality, it will be placed at the position of the sleeve-interlocking pile furthest from the central axis within the pile top plane. To improve the feasibility of engineering design and construction, a simplified algorithm is implemented: The interlocking amount of the added jet grouting pile foundation = rounded to the nearest integer {0.5R-100-rounded to the nearest integer [R / 6-100]}, The interlocking amount of two jet grouting piles with different radii = {0.25(R1+R2)-100-[(R1+R2) / 12-100]} (rounded to the nearest integer after rounding ... The interlocking amount between jet grouting piles and casing-interlocking piles is calculated based on the diameter of the jet grouting pile. When adding one high-pressure jet grouting pile, the vertical line where the bite amount is located at the depth of 2 / 3*(H3+3) is taken as the center of the high-pressure jet grouting pile. The distance P from the center of the high-pressure jet grouting pile to the bite amount connection line is the radius R + the actual bite amount, i.e., R + 1.5X. When X is less than 0, it is taken as 0. When n high-pressure jet grouting piles are added, one pile is set as described above; the remaining n-1 piles are arranged symmetrically, with the axis of symmetry being the centerline of the bite amount at a depth of 0.5*(H3+3).

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