CN111794292A - Plain concrete pile static test anchor pile counter-force technology based on post-planting bars - Google Patents
Plain concrete pile static test anchor pile counter-force technology based on post-planting bars Download PDFInfo
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- CN111794292A CN111794292A CN201911033472.6A CN201911033472A CN111794292A CN 111794292 A CN111794292 A CN 111794292A CN 201911033472 A CN201911033472 A CN 201911033472A CN 111794292 A CN111794292 A CN 111794292A
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D33/00—Testing foundations or foundation structures
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/22—Piles
- E02D5/64—Repairing piles
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Abstract
The invention provides a post-planting-reinforcement-based anchor pile counterforce technology for a static load test of a plain concrete pile, which comprises the steps of calculating, distributing, calculating the comprehensive success rate, implementing and finishing the static load test; the calculation comprises the steps of calculating and determining the specification and the depth of the steel bars of the embedded pile body and the quantity of the grouped piles participating in the reaction according to the design bearing capacity and the pile foundation distribution condition of the plain concrete pile so as to meet the sufficient reaction required by the static load test; the step of distributing comprises: the quantity of the grouped piles participating in the reaction is even as much as possible and is symmetrically distributed; one or more steel bars can be implanted into each pile; although only one or a small amount of steel bars are implanted into the anchor pile, on the basis of scientific calculation, a large number of field test researches show that the static load test does not cause any damage to the concrete of the anchor pile body and does not generate any tensile crack. The pile body is complete and does not bear excessive tensile load of post-planting bars and static load tests. On-site pile group resources are fully mobilized, and the post-bar planting mode is flexible.
Description
Technical Field
The invention relates to the technical field of plain concrete piles, in particular to a reverse force technology of a plain concrete pile static load test anchor pile based on post-planting bars.
Background
Plain concrete piles, such as CFG piles (i.e. Cement Fly-ash Gravel piles) are one of the types of piles commonly used in building foundations. The pile body of the pile does not contain any steel bar, and the external load is borne by concrete only, so the pile is called a plain concrete pile. The diameter of a common plain concrete pile is about 500mm, the pile length is less than 25m, the characteristic value of the vertical compression bearing capacity of a single pile is about 1000kN, and the characteristic value of the bearing capacity of a single-pile composite foundation is about 500 kPa. According to the pile foundation detection standard requirement, the bearing capacity detection needs to adopt a static load test of a ballast platform counter-force mode, namely, heavy objects (such as large equipment like a balancing weight, a steel beam and the like) which are not less than 2.4 times of the designed bearing capacity characteristic value are transported to the site. Although the static load test using the traditional reaction mode can obtain a relatively accurate bearing force result, the static load test has a plurality of defects and limitations, such as complicated and heavy hoisting machinery and equipment, long operation time, potential safety hazards and high test cost; the method has the advantages of large occupied area, incapability of testing due to narrow area, low sampling rate, poor representativeness of test results and the like. In addition, since the plain concrete pile does not contain a reinforcing steel bar inside the pile body, a static load test of the anchor pile reaction force method cannot be performed like a reinforced concrete pile. Therefore, for plain concrete piles, a new counter-force technique is needed, which can overcome the above-mentioned disadvantages and limitations of the conventional counter-force method and provide a sufficiently large counter-force to obtain an accurate bearing force test result.
The invention discloses a pile anchor reaction technology based on post-embedded reinforcement for a static load test of a plain concrete pile, which is based on the full utilization of pile groups close to a tested pile by using the working principle of a reinforced concrete pile anchor reaction mode for reference. The basic principle of the technology is that reinforcing steel bars with certain specifications are implanted into plain concrete piles to form anchor piles, the anchor piles form a counter-force system, and sufficient counter-force is provided for single-pile or composite foundation static load tests.
According to the design bearing capacity and pile foundation distribution of the plain concrete pile, the specifications (such as D12, D14, D16, D18, D20, D22, D25, D28 and D32) and the depth of the steel bars of the implanted pile body and the number of the piles participating in the reaction force action are calculated and determined so as to meet the sufficient reaction force required by the static load test. The quantity of the grouped piles participating in the reaction is even as much as possible and is symmetrically distributed. Thus, the reaction force is uniform and the reaction force beam frame is convenient to set up. One or more steel bars can be implanted into each pile. The efficiency and the success rate of bar planting are comprehensively considered, and it is advisable to implant one steel bar into each pile. Then, vertically drilling a hole in the center of the pile top of the selected pile by using a portable drilling machine on site, wherein the depth is generally 1-3 m, and the verticality is preferably less than 1%; vertically placing the calculated steel bars with certain specifications into the drill holes, wherein the exposed length of the steel bars depends on static load test equipment; and filling and gluing a gap between the steel bar and the drilled hole by using a strong injection type bar planting glue. And (4) planting bars in sequence according to the flow for all the selected grouped piles participating in the reaction. The steel bar and the bar planting glue are solidified for about 24 hours. That is to say, the reaction force requirement of the static load test can be met after the steel bars are planted and the steel bars are stopped for one day, so that a large amount of test cost and construction period can be saved. All the pile groups subjected to post-planting reinforcement form an anchor pile group providing enough counter force. Finally, all post-planted steel bars, the main beam and the secondary beam are firmly connected by using special steel tie beams, locks, jacks and other components, and a static load test is started and completed. Thus, the complete static load test of the plain concrete pile is formed.
The invention connects the group piles which are close to the symmetrical or approximately symmetrical distribution of the tested piles with the counterforce beam frame through the post-implanted steel bars to form a counterforce whole; and a jack at the top of the pile top (single-pile static load test) or the load plate (composite foundation static load test) applies load to the counter-force beam frame. Because the uplift resistance of the anchor pile group is far greater than the maximum load applied by the jack, all levels of loads required by the static load test are reacted on the pile top to apply uniform vertical load to the pile foundation under the pile body or the load plate. For the plain concrete pile, the invention not only meets the counterforce requirement of the static load test, but also has the obvious advantages of science, reasonability, economy, simplicity, convenience and the like.
Therefore, the invention is necessary to invent a pile anchor reaction force technology for the static load test of the plain concrete pile based on the post-planting bars.
Disclosure of Invention
Aiming at the prior art, the invention mainly aims to provide a reverse force technology of a plain concrete pile static load test anchor pile based on post-planting bars.
In order to solve the technical problems, the invention provides a pile anchor reaction technology for a static load test of a plain concrete pile based on post-planting bars, which comprises reaction calculation, distribution, comprehensive success rate calculation, implementation and static load test completion; the counter-force calculation comprises the steps of calculating and determining the specification and the depth of the steel bars of the implanted pile body and the quantity of the piles participating in the counter-force action according to the design bearing capacity and the pile foundation distribution condition of the plain concrete pile so as to meet the sufficient counter-force required by the static load test;
the step of distributing comprises: the quantity of the grouped piles participating in the reaction is even as much as possible and is symmetrically distributed; implanting one or more steel bars into each pile;
the comprehensive success rate calculating step comprises the steps of comprehensively considering the efficiency and the success rate of bar planting, and planting a steel bar into each pile; filling and gluing a gap between the steel bar and the drilled hole by adopting a strong injection type bar-planting glue; and (4) planting bars in sequence according to the flow for all the grouped piles participating in the reaction.
Furthermore, the steel bars and the bar planting glue need to be fixed for about 24 hours; the pile group of the post-planting bars forms an anchor pile group providing enough counter force.
Further, the completion of the static test comprises the steps of utilizing components such as a special steel tie beam, a lock, a jack and the like to firmly connect all post-planted steel bars, the main beam and the secondary beam for the test, and starting and completing the static test.
Furthermore, the reaction force requirement of the static load test can be met after the steel bar is planted and the steel bar is stopped for one day.
The invention has the beneficial effects that:
1. the post-embedded steel bar anchor pile counterforce technology fully utilizes the plain concrete pile adjacent to the tested pile, forms an anchor pile group through post-embedded steel bars, and meets the requirement of large enough counterforce required by a static load test. According to the bearing capacity requirement, the quantity of the grouped piles participating in the reaction can be selected and determined at will according to local conditions and local materials. Compared with the traditional method, the cost of post-planting bars is very low, a large amount of heavy equipment such as pile-loading counter weights and heavy steel beams does not need to be transported, hoisted and disassembled, and the input test cost such as manpower, material resources and financial resources is greatly reduced. A great deal of experience shows that the test cost can be saved by more than 80 percent.
2. The process for planting the steel bars after the plain concrete pile is fast, simple and easy to operate, and can meet the static load test requirement by only needing to stop for 24 hours to finish the gluing and fixing. Compared with the traditional method, the construction period of the static load test of the single pile or the composite foundation is greatly reduced. Because the invention fully mobilizes the resources of pile groups on site and the post-planting mode is flexible, the static load test of a plurality of piles can be carried out at the same time, and the next pile test is not needed after the test of one pile is finished like the traditional method. For this reason, the full application of the invention will further reduce the construction period greatly for the whole project.
3. The invention can flexibly select the pile group participating in the reaction force to carry out post-bar planting treatment, and the static load test is hardly limited by site conditions and loading tonnage. In the case that a certain number of piles exist in the adjacent area, the positions of the tested piles or the load plate points can be randomly specified. Compared with the traditional method with harsh requirements on site conditions, the method has the advantages of higher sampling rate and higher representativeness of test results, and can more scientifically and accurately reflect the actual conditions of the engineering.
4. The counter force in the invention is derived from the resultant force of the anchor pile group in the area adjacent to the tested pile, and the counter force born by any one pile is relatively limited. Therefore, the specially-made counterforce beam frame and the lockset required by connecting and fixing the post-planting steel bars, the test main beam, the secondary beam and the like are light, and compared with the traditional method, the invention can effectively avoid the occurrence of personal safety accidents.
5. Although only one or a small amount of steel bars are implanted into the anchor pile, on the basis of scientific calculation, a large number of field test researches show that the static load test does not cause any damage to the concrete of the anchor pile body and does not generate any tensile crack. The pile body is complete, and the overlarge tension load of post-planting bars and static load tests is not borne, so that no negative influence is caused on the engineering.
Detailed Description
The present invention is further illustrated by the following examples, which include, but are not limited to, the following examples.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
the invention provides a post-planting-reinforcement-based anchor pile counterforce technology for a static load test of a plain concrete pile, which comprises the steps of calculating, distributing, calculating the comprehensive success rate, implementing and finishing the static load test; the calculation comprises the steps of calculating and determining the specification and the depth of the steel bars of the embedded pile body and the quantity of the grouped piles participating in the reaction according to the design bearing capacity and the pile foundation distribution condition of the plain concrete pile so as to meet the sufficient reaction required by the static load test;
the step of distributing comprises: the quantity of the grouped piles participating in the reaction is even as much as possible and is symmetrically distributed; one or more steel bars can be implanted into each pile;
the comprehensive success rate calculating step comprises comprehensively considering the efficiency and the success rate of bar planting, and preferably, one steel bar is planted in each pile;
the implementation steps comprise that a portable drilling machine is adopted to vertically drill a hole in the center of the pile top of a selected pile on site, the depth is generally 1-3 m, and the verticality is preferably less than 1%; vertically placing the calculated steel bars with certain specifications into the drill holes, wherein the exposed length of the steel bars depends on static load test equipment; filling and gluing a gap between the steel bar and the drilled hole by adopting a strong injection type bar-planting glue; all the selected pile groups participating in the reaction are sequentially subjected to bar planting according to the process; the reinforcing steel bars and the bar planting glue are fixed for about 24 hours; all the pile groups subjected to post-planting reinforcement form an anchor pile group providing enough counter force.
And the completion of the static load test comprises the steps of utilizing components such as a special steel tie beam, a lock, a jack and the like to firmly connect all post-planted steel bars, a test main beam and a secondary beam, and starting and completing the static load test.
The reaction force requirement of the static load test can be met after the steel bars are planted and the steel bars are stopped for one day, so that a large amount of test cost and construction period can be saved.
The technical solutions of the present invention or similar technical solutions designed by those skilled in the art based on the teachings of the technical solutions of the present invention are all within the scope of the present invention.
Claims (4)
1. A kind of anchor pile reaction force technology of static load test of plain concrete pile based on post-planting bar, including reaction force calculation, distribution, the calculation of the comprehensive success rate, implement, finish the static load test; the method is characterized in that the counter-force calculation comprises the steps of calculating and determining the specification and the depth of embedded pile body reinforcing steel bars and the quantity of piles participating in the counter-force action according to the design bearing capacity and pile foundation distribution condition of plain concrete piles so as to meet the sufficient counter-force required by a static load test;
the step of distributing comprises: the quantity of the grouped piles participating in the reaction is even as much as possible and is symmetrically distributed; implanting one or more steel bars into each pile;
the comprehensive success rate calculating step comprises the steps of comprehensively considering the efficiency and the success rate of bar planting, and planting a steel bar into each pile; filling and gluing a gap between the steel bar and the drilled hole by adopting a strong injection type bar-planting glue; and (4) planting bars in sequence according to the flow for all the grouped piles participating in the reaction.
2. The anchor pile reaction force technology for the static load test of the plain concrete pile based on the post-planting bars as claimed in claim 1 is characterized in that: the reinforcing steel bars and the bar planting glue are fixed for about 24 hours; the pile group of the post-planting bars forms an anchor pile group providing enough counter force.
3. The anchor pile reaction force technology for the static load test of the plain concrete pile based on the post-planting bars as claimed in claim 1 is characterized in that: and the completion of the static load test comprises the steps of utilizing components such as a special steel tie beam, a lock, a jack and the like to firmly connect all post-planted steel bars, a test main beam and a secondary beam, and starting and completing the static load test.
4. The anchor pile reaction force technology for the static load test of the plain concrete pile based on the post-planting bars as claimed in claim 1 is characterized in that: the reaction force requirement of the static load test can be met after the bar is planted and the bar is stopped for one day.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911033472.6A CN111794292A (en) | 2019-10-28 | 2019-10-28 | Plain concrete pile static test anchor pile counter-force technology based on post-planting bars |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911033472.6A CN111794292A (en) | 2019-10-28 | 2019-10-28 | Plain concrete pile static test anchor pile counter-force technology based on post-planting bars |
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| CN111794292A true CN111794292A (en) | 2020-10-20 |
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| CN201911033472.6A Pending CN111794292A (en) | 2019-10-28 | 2019-10-28 | Plain concrete pile static test anchor pile counter-force technology based on post-planting bars |
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201520988U (en) * | 2009-10-10 | 2010-07-07 | 中交上海港湾工程设计研究院有限公司 | Physical pile group vertical uplift-resisting static load testing system |
| KR20100090325A (en) * | 2009-02-06 | 2010-08-16 | (주)한국품질시험연구소 | Schematic installation and connecting method of pile load test using reaction pile |
| CN102535532A (en) * | 2012-02-17 | 2012-07-04 | 中建三局第二建设工程有限责任公司 | Anchor rib-steel beam combined counter-force device |
| CN103967289A (en) * | 2014-04-23 | 2014-08-06 | 江苏建研建设工程质量安全鉴定有限公司 | Steel bar planting method and steel bar planting structure suitable for improving plain concrete post-installed fastening bearing capacity |
| CN107012899A (en) * | 2017-06-08 | 2017-08-04 | 攀枝花天誉工程检测有限公司 | Foundation pile static loading test system |
| CN208533582U (en) * | 2018-03-29 | 2019-02-22 | 广州市建筑科学研究院有限公司 | A kind of existing building reinforcing pile foundation static loading test device |
| CN110306830A (en) * | 2019-07-22 | 2019-10-08 | 江苏苏南建筑安装工程有限公司 | A kind of implantation bar construction and pore reinforced construction method |
-
2019
- 2019-10-28 CN CN201911033472.6A patent/CN111794292A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20100090325A (en) * | 2009-02-06 | 2010-08-16 | (주)한국품질시험연구소 | Schematic installation and connecting method of pile load test using reaction pile |
| CN201520988U (en) * | 2009-10-10 | 2010-07-07 | 中交上海港湾工程设计研究院有限公司 | Physical pile group vertical uplift-resisting static load testing system |
| CN102535532A (en) * | 2012-02-17 | 2012-07-04 | 中建三局第二建设工程有限责任公司 | Anchor rib-steel beam combined counter-force device |
| CN103967289A (en) * | 2014-04-23 | 2014-08-06 | 江苏建研建设工程质量安全鉴定有限公司 | Steel bar planting method and steel bar planting structure suitable for improving plain concrete post-installed fastening bearing capacity |
| CN107012899A (en) * | 2017-06-08 | 2017-08-04 | 攀枝花天誉工程检测有限公司 | Foundation pile static loading test system |
| CN208533582U (en) * | 2018-03-29 | 2019-02-22 | 广州市建筑科学研究院有限公司 | A kind of existing building reinforcing pile foundation static loading test device |
| CN110306830A (en) * | 2019-07-22 | 2019-10-08 | 江苏苏南建筑安装工程有限公司 | A kind of implantation bar construction and pore reinforced construction method |
Non-Patent Citations (3)
| Title |
|---|
| 中国水利水电第七工程局有限公司: "《高速铁路核心技术汇展 京沪高速铁路无砟轨道系统建造》", 31 January 2011, 天津科技翻译出版公司 * |
| 席永哲等: "镇城底选煤厂原煤仓基桩施工及检测", 《山西焦煤科技》 * |
| 王金玉: "《建设工程质量检测技术 第3册》", 31 March 2011, 中国矿业大学出版社 * |
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