CN-117403710-B - Blocking type negative friction resistance test pile and pouring method thereof

CN117403710BCN 117403710 BCN117403710 BCN 117403710BCN-117403710-B

Abstract

The invention provides a blocking type negative friction resistance test pile and a pouring method thereof, which belong to the technical field of foundation pile pouring, wherein the test pile is of a broken pile structure and comprises a plurality of sections of pile bodies and foundation pile negative friction resistance blocking type test elements buried between two adjacent sections of pile bodies, each pile body comprises a reinforcement cage and a concrete layer poured outside the reinforcement cage, each reinforcement cage comprises a plurality of round test main ribs distributed at equal intervals, each foundation pile negative friction resistance blocking type test element comprises an element I and an element II, and each element I and each element II comprise an upper blocking plate, a protective blocking layer, a lower blocking plate and a reinforcement stress meter connecting piece. The invention can reduce the cost, shorten the construction period and improve the economic benefit and the negative friction resistance value accuracy.

Inventors

YANG LONGXIAN
ZHANG JIEYU
GAO WENQING
LIANG JIN
LI XUEDONG
YANG WEIWEI
CHEN JIANYE
ZHANG JIANYUN
LI BAOPING
YANG LIN
ZHANG SONGBAI

Assignees

山西机械化建设集团有限公司

Dates

Publication Date: 20260512
Application Date: 20231027

Claims (10)

1. The blocking type negative friction resistance test pile is characterized by being of a broken pile structure and comprising a plurality of sections of pile bodies (1) and foundation pile negative friction resistance blocking type test elements (2) buried between two adjacent sections of pile bodies (1); the pile body (1) comprises a reinforcement cage and a concrete layer poured outside the reinforcement cage; The steel reinforcement cage comprises a plurality of circular test main ribs (1.1) distributed at equal intervals; The foundation pile negative friction resistance blocking type test element (2) comprises an element I and an element II; The element I and the element II comprise an upper blocking plate (2.1), a protective isolating layer (2.2), a lower blocking plate (2.3) and a reinforcing steel bar stress meter connecting piece (2.8); The upper blocking plate (2.1), the protective isolation layer (2.2) and the lower blocking plate (2.3) are of annular structures, the upper blocking plate (2.1) and the lower blocking plate (2.3) are respectively arranged on the upper surface and the lower surface of the protective isolation layer (2.2), the center holes of the upper blocking plate, the protective isolation layer and the lower blocking plate are coaxially arranged and axially communicated with each other to form grouting holes (2.4), and the axial communicated stress meter through holes (2.5) are formed according to the number and the positions of the main ribs (1.1) in each pile body (1); The diameter of the central hole of the protective isolation layer (2.2) is smaller than that of the central hole of the upper blocking plate (2.1), connecting wire protection grooves (2.6) are formed in the upper surface of the protective isolation layer (2.2), the connecting wire protection grooves (2.6) are in one-to-one correspondence with the stress meter perforation holes (2.5), the first ends of the connecting wire protection grooves are communicated with the stress meter perforation holes (2.5), and the second ends of the connecting wire protection grooves are located between the central hole of the protective isolation layer (2.2) and the central hole of the upper blocking plate (2.1); The steel bar stress meter connecting piece (2.8) comprises a steel bar stress meter (2.9), an upper connecting rib (2.10) and a lower connecting rib (2.11) which are positioned at two ends of the steel bar stress meter (2.9), the steel bar stress meter connecting piece (2.8) penetrates through the stress meter perforation (2.5), the upper end of the upper connecting rib (2.10) and the lower end of the lower connecting rib (2.11) are positioned outside the stress meter perforation (2.5), and a connecting line (2.12) of the steel bar stress meter (2.9) is led out from the second end of the connecting line protection groove (2.6); the second end of the connecting wire protection groove (2.6) in the element II is provided with a connecting wire perforation (2.7) which is axially penetrated; the element I is arranged at the lowest pile breaking position, the element II is arranged at the pile breaking position above the element I, and the upper ends of the upper connecting ribs (2.10) and the lower ends of the lower connecting ribs (2.11) of the element I and the element II are respectively welded with the test main ribs (1.1) of the two adjacent pile bodies (1); in the element I, connecting wires (2.12) of the reinforcing steel bar stress gauge (2.9) are led out from the second end of the connecting wire protection groove (2.6), and then pass through connecting wire perforation holes (2.7) of all the elements II from bottom to top in sequence; In the element II installed at the uppermost pile breaking position, a connecting wire (2.12) of a reinforcing steel bar stress meter (2.9) is led out from a second end of a connecting wire protection groove (2.6); In the element II below the uppermost pile breaking position, connecting wires (2.12) of the reinforcing steel bar stress gauge (2.9) are led out from the second end of the connecting wire protection groove (2.6), and then pass through connecting wire perforation holes (2.7) of all the elements II above from bottom to top in sequence; the concrete layer of each pile body (1) is of an annular structure, the inner diameter of the concrete layer is matched with the diameter of the central hole of the protective isolation layer (2.2), and the outer diameter of the concrete layer is matched with the diameter of the foundation pile drilling hole (3).
2. The blocking type negative friction resistance test pile according to claim 1, wherein the reinforcement cage of each pile body (1) further comprises a plurality of auxiliary main ribs (1.2) which are distributed at equal intervals in a round shape, the auxiliary main ribs (1.2) and the test main ribs (1.1) are arranged in a staggered mode, and two ends of each auxiliary main rib (1.2) are welded with an upper blocking plate (2.1) and a lower blocking plate (2.3) of each adjacent two groups of foundation pile negative friction resistance blocking type test elements (2) respectively.
3. The blocking type negative frictional resistance test pile according to claim 1, wherein both ends of the reinforcing bar stress gauge (2.9) are respectively connected with the upper connecting rib (2.10) and the lower connecting rib (2.11) through screw threads.
4. The blocking type negative frictional resistance test pile according to claim 1, wherein the protective barrier layer (2.2) is a polystyrene board.
5. The blocking type negative frictional resistance test pile according to claim 1, wherein the upper connection rib (2.10) is welded with the upper blocking plate (2.1), and the lower connection rib (2.11) is welded with the lower blocking plate (2.3).
6. A method of casting a blocking type negative frictional resistance test pile according to any one of claims 1 to 5, comprising the steps of: S1, drilling holes at preset positions of a site; s2, a reinforcement cage is arranged, and a foundation pile negative friction resistance blocking type test element (2) is arranged; the upper end of an upper connecting rib (2.10) and the lower end of a lower connecting rib (2.11) in the element I are respectively welded with test main ribs (1.1) at two sides of the lowest pile breaking position; In the process of the lower reinforcement cage, sequentially installing elements II from bottom to top along the reinforcement cage, wherein the upper ends of upper connecting ribs (2.10) and the lower ends of lower connecting ribs (2.11) in the elements II are respectively welded with test main ribs (1.1) at two sides of a pile breaking position; every time a group of elements II are installed, connecting lines (2.12) of the element I below the group of elements II and the reinforcing steel bar stress gauge (2.9) in the element II penetrate through connecting line perforation (2.7) of the group of elements II until all the elements II are installed; s3, installing a grouting guide pipe (4) along the grouting hole (2.4), wherein the bottom end of the grouting guide pipe (4) is positioned below the element I, and the outer diameter of the grouting guide pipe (4) is matched with the diameter of the central hole of the protective isolation layer (2.2); S4, pouring concrete through the grouting guide pipe (4); And S5, after the concrete age meets the requirements, taking out the grouting guide pipe (4) and the concrete therein and the concrete below the grouting guide pipe (4) to form the blocking type negative friction resistance test pile.
7. The casting method according to claim 6, further comprising step S0 of performing a field power penetration test and a shear wave velocity test to determine the depth of embedment of the test pile position and foundation pile negative frictional resistance blocking type test element (2).
8. The pouring method according to claim 7, wherein in the step S1, the foundation pile drilling (3) is formed by using a rotary drilling machine, the depth of the formed hole is determined according to the result of the step S0 and the foundation pile drilling (3) is introduced into the bearing layer, and the foundation pile drilling is performed after the foundation pile drilling is performed.
9. Pouring method according to claim 6, characterized in that the grouting conduits (4) are tied to the reinforcement cage and a plurality of grout holes are provided at positions between adjacent two groups of foundation pile negative friction resistance blocking type test elements (2).
10. Pouring method according to claim 6, characterized in that the top end of the grouting conduit (4) is fitted with a conical chute funnel (5); the grouting guide pipe (4) is connected by a plurality of sections of PVC pipes by adopting buckles and is coated with glue.

Description

Blocking type negative friction resistance test pile and pouring method thereof Technical Field The invention belongs to the technical field of foundation pile pouring, and particularly discloses a blocking type negative friction resistance test pile and a pouring method thereof. Background When a site formed by large-thickness disordered backfilling of an open mining area, a natural gully, a sea filling land and the like is used as a building foundation, the site can be effectively reinforced, but a certain post-construction settlement still exists after the site, so that a pile foundation for later construction still can have a certain negative friction, the safety performance of a building structure is influenced, and certain loss is caused to building safety and lives and properties of people. At present, the research on the negative friction of the cast-in-place pile after the large-thickness disordered backfill site is adopted in the industry is very few, and the accuracy of the negative friction value is low. The common foundation pile negative friction testing methods are only few: 1. The prediction calculation provides a calculation formula for estimating when the pile foundation is designed, but the calculation formula is compared with the results of pile body side stress, pull-down load and the like detected on site, and the conservation of calculation is confirmed, so that the engineering cost is increased according to the design, and a certain waste is caused; 2. pile side piling, namely pile body embedding blocking type components, and applying pressure to soil around the pile through pile side piling, wherein the pile side piling has higher requirements on the site, needs wider site, has high cost and long construction period, and is inconsistent with the site construction environment; 3. The simulation device tests various pile foundation models to test the negative friction resistance around the pile, and the simulation device has larger difference with the actual situation on site and has low accuracy of the negative friction resistance. Disclosure of Invention The invention provides a blocking type negative friction resistance test pile and a pouring method thereof, which are used for reducing the cost, shortening the construction period and improving the economic benefit and the accuracy of a negative friction resistance value. The invention provides a blocking type negative friction resistance test pile which is of a broken pile structure and comprises a plurality of sections of pile bodies and foundation pile negative friction resistance blocking type test elements buried between two adjacent sections of pile bodies, wherein each pile body comprises a reinforcement cage and a concrete layer poured outside the reinforcement cage, each reinforcement cage comprises a plurality of round equidistant test main ribs, each foundation pile negative friction resistance blocking type test element comprises an element I and an element II, each element I and each element II comprises an upper blocking plate, a protective isolation layer, a lower blocking plate and a reinforcing bar stress gauge connecting piece, each upper blocking plate, each protective isolation layer and each lower blocking plate are of annular structures, the upper surface and the lower surface of each protective isolation layer are respectively provided with an upper surface and a lower surface of each protective isolation layer, the central holes of the three are coaxially arranged and axially penetrated into grouting holes, the number and the positions of the test main ribs are provided with axially penetrated stress gauge perforations according to the number and the positions of the reinforcement bars in each section of pile bodies, the central holes of each protective isolation layer are smaller than the diameters of the central holes of the upper blocking plates, the upper surfaces of the protective isolation layers are provided with connecting wire protection grooves, the connecting wire protection grooves are in one-to-one correspondence with the stress gauge, the connecting wire protection grooves are respectively arranged on the upper surfaces of the upper surface of the protective isolation layers, the upper end of each protection isolation layer is provided with a connecting wire, the connecting wire is in one-to the second end of the corresponding stress gauge, the connecting wire is in one-to the one end of the second end of the protection isolation layer is in the one-to the one end of the two end of the protection layer, the two end of each protection layer are respectively, each protection layer is provided with a connecting wire, and one through stress meter, and each connecting wire is arranged at the connecting bar, and each stress-stop bar is arranged at the end, and each stress-stop-to each stress-to, and has. The upper ends of the upper connecting ribs and the lower ends of the lower connecting ribs of th