CN114293533A - Uniform reinforcement structure for vibroflotation pile composite foundation and design method - Google Patents
Uniform reinforcement structure for vibroflotation pile composite foundation and design method Download PDFInfo
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Abstract
The application relates to a vibroflotation pile composite foundation uniform reinforcement structure and a design method, which belong to the technical field of vibroflotation piles, and the reinforcement structure comprises a gravel pile and a gravel earth surface reinforcement layer with a certain thickness, wherein the gravel pile is arranged at the top of the gravel pile. Because the surface reinforcing layer is internally provided with natural drainage pores, the surface reinforcing layer and the gravel pile can quickly dissipate the excess pore water pressure in the stratum under the action of an earthquake, and the risk of stratum liquefaction is reduced; meanwhile, the earth surface reinforcing layer has the functions of uniformly bearing upper load and avoiding the differential settlement of the vibroflotation pile composite foundation. The design method of the application adopts numerical simulation analysis to obtain the optimal arrangement scheme of the gravel pile group, the required minimum pile number and the minimum thickness of the earth surface reinforcing layer, and the optimized design method is scientific and reasonable, so that the actual construction load is in accordance with the design load, and the effect of accurately controlling the construction cost is achieved.
Description
Technical Field
The application relates to the technical field of vibroflotation piles, in particular to a vibroflotation pile composite foundation uniform reinforcement structure and a design method.
Background
The vibroflotation method, also called as vibroflotation method, is a foundation consolidation method developed based on the principle that the soft foundation such as sandy soil can be compacted by adding water and vibrating, and is later used for arranging vibroflotation replacement gravel piles in the cohesive soil layer. The vibroflotation method is a foundation reinforcement treatment method for improving poor foundation and meeting the foundation requirements of buildings (structures).
The vibroflotation pile is characterized in that sand grains, broken stones, cohesive soil and the like are extruded into holes or cracks in a soft foundation with overlarge pore cracks by using a vibration mode and combined with soil around the foundation to form a new composite foundation. The vibroflotation pile method is suitable for foundations of miscellaneous fill, loose sandy soil, cohesive soil, silt and the like. The foundation treated by the vibroflotation pile method can fully utilize the strength advantage of the natural foundation and make the foundation uniform in strength. The vibroflotation method can quickly finish the drainage consolidation of the soft foundation, enhance the strength of the foundation, and improve the bearing capacity and the liquefaction resistance to improve the stability of the foundation.
The vibroflotation gravel pile composite foundation reinforcing technology originates from Europe in 19 th century, is used for reinforcing the foundations of war factory workshops in Bayonne areas of France, only uses a simple gravel pile reinforcing method to process loose gravel, and has certain limitation on development and application due to insufficient physical and mechanical theory support and advanced test facilities. In 1936, s. Steuerman in germany proposed the concept of compacting sandy soil with vibration assisted by pressurized water. In 1937, Johann Keller, germany, developed the first vibroflot in the world. In the period of 1930-1940, vibroflotation is widely applied to the treatment of sand foundation in Germany. The early German practice proves the superiority of the method, the equipment is simple, the efficiency is high, and the method lays a foundation for the later long-term development. In 1950-1960 s, Germany and UK successively promoted the vibroflotation method for cohesive soil. The engineering foundation of Nelumberg Germany has soft clay, and Keller adopts a construction process of firstly forming holes by a vibroflot and then filling stones for reinforcement, which is the bud of the 'gravel pile method' of today. The vibration and impact method is used abroad in many cases, wherein the vibration and impact method is used for treating the sand foundation in the ten-win scouring region of Japan, and the vibration and impact method plays a remarkable role in 7.7-grade strong earthquakes in 1968, effectively inhibits the liquefaction of the sand foundation and proves the effectiveness of the vibration and impact method in the treatment of the sand foundation. Thereafter, the vibroflotation method is listed as a measure for effectively treating the seismic reinforcement of the sand foundation.
The geotechnical engineering world in China starts to understand and pay attention to the application condition of foreign vibroflotation technology in the middle of the 70 th century in 20 th century, and China pays attention to the technical research on seismic strengthening treatment of foundations and foundations. The vibroflotation technology development in China can be divided into four stages such as introduction tests (1976-1983), popularization and application (1984-1999), comprehensive and wide application (2000-2011) and process and technology improvement (2012-now) to date. With the development of infrastructure construction in recent decades, the vibro-replacement gravel pile construction technology and equipment in China are rapidly developed and applied.
The reinforcing mechanism of the vibroflotation pile is as follows:
the sandy soil is a single-grain structure, and the compact single-grain structure is close to a stable state and can not generate large deformation under the action of load. In a loose single-grain structure, the pores among the grains are large, the positions of the grains are unstable, and displacement is easily generated under the action of dynamic load or static load, so that large deformation can be generated. Particularly under the action of vibration load, the volume can be reduced by 20%. Therefore, loose sandy soil cannot be used as a building foundation without treatment. The main purpose of the gravel pile (vibroflotation method or dry vibration method) for reinforcing sandy soil foundation is to improve the bearing capacity and modulus of foundation soil and enhance the liquefaction resistance, and the reinforcing mechanism of the liquefaction resistance has the following three functions:
(1) compaction effect
In the vibroflotation compaction method, loose sandy soil is in a saturated state due to water flushing in the construction process, the sandy soil is liquefied under strong high-frequency forced vibration and is rearranged to be compact, and after a large amount of coarse aggregate is filled in pile holes, the pile holes are squeezed into surrounding soil by strong horizontal vibration force, so that the relative compactness of the sandy soil is increased, the porosity is reduced, the dry density and the internal friction angle are increased, the physical and mechanical properties of the soil are improved, the bearing capacity of a foundation is greatly improved, and the liquefaction resistance is improved. The domestic reports indicate that: as long as the content of fine particles smaller than 0.074mm does not exceed 10%, a compacting effect can be obtained.
(2) Effect of pressure reduction of drainage
Research on the liquefaction mechanism of sandy soil proves that when saturated loose sandy soil is subjected to the action of shearing cyclic load, the saturated loose sandy soil shrinks in volume and tends to be compact. Under the condition of no drainage of sandy soil, the rapid contraction of the volume can lead to the rapid increase of the ultra-static pore water pressure due to insufficient dissipation, and when the effective stress in the sandy soil is reduced to zero, the complete liquefaction is formed. When the gravel pile is used for reinforcing sand, coarse particles with good reverse filtration performance are filled in the pile hole, and an artificial vertical drainage pressure reduction channel with good permeability is formed in the foundation, so that the increase of the water pressure in the excess pore space can be effectively dissipated, the sand is prevented from being liquefied, and the drainage consolidation of the foundation can be accelerated.
(3) Pre-shock effect
Tests prove that under a certain cycle, when the relative densities of two samples are the same, the stress required for liquefying the pre-shocked sample is increased by 46 percent compared with the stress required for liquefying the non-pre-shocked sample, so that the liquefaction characteristic of the sandy soil is obtained, and besides the relative compactness of the soil, the conclusion about the vibration strain is also obtained. When a vibrator is used for construction by a vibroflotation method, when the vibrator is sprayed with water and sinks into soil at 1450 times of vibration frequency per minute, 98m/s horizontal acceleration and 90kN exciting force, the filler and the foundation soil are compacted and simultaneously obtain strong pre-vibration, which is very favorable for enhancing the liquefaction resistance of the sandy soil.
At present, the design and construction of the vibroflotation pile composite foundation only consider key pile arrangement schemes and parameters such as bearing capacity, pile diameter, space, quantity and the like, a small-proportion sampling inspection method is adopted for vibroflotation pile construction inspection and detection in relevant technical specifications, and the inventor finds that due to incompleteness of geological survey, randomness of vibroflotation pile site arrangement and sampling inspection randomness of construction inspection and detection, common adverse geological conditions such as local weak underlying layers, local cavities (gaps), local weak stratums (underground water layers) and the like are easy to occur in a wide vibroflotation construction field, so that the problem of uneven settlement is easy to occur in the construction of large-scale structures on the vibroflotation composite foundation after vibroflotation pile construction, and great potential safety hazards exist in an overground structure system of the vibroflotation composite foundation.
Disclosure of Invention
In order to effectively weaken the phenomenon of uneven settlement of a composite foundation caused by local weak strata, the application provides a vibroflotation pile composite foundation uniform reinforcement structure and a design method.
First aspect, the application provides a vibroflotation pile composite foundation uniform reinforcement structure, adopts following technical scheme:
the utility model provides an even reinforced structure of vibroflotation pile composite foundation, includes gravel pile and the earth's surface back up coat that rolls with permeable material preparation, and the gravel pile is located the composite stratum, and the earth's surface back up coat covers on the composite stratum earth's surface, and the earth's surface back up coat is connected with gravel pile top.
Through adopting above-mentioned technical scheme, the earth's surface back up coat is just like "desktop", rolls in order to increase the closely knit degree of earth's surface back up coat, strengthens the interlock effect of gravel pile and soil, promotes the bearing capacity. The gravel pile is just like the "table post" that supports, and the same load effect in ground upper portion transmits for "table post" through "desktop", transmits for the gravel pile through the earth's surface back up coat promptly, compares in direct action on the gravel pile, "table post" more the ground atress more even, bearing capacity is big more, the ground is whole subsides more and more is in coordination unanimous, can effectively avoid or weaken the phenomenon of the inhomogeneous settlement of composite foundation that local weak layer brought.
Optionally, the ground surface reinforcing layer is made of crushed stone, and the crushed stone ground surface reinforcing layer naturally has a drainage channel, so that the super-pore water pressure generated by the lower liquefiable stratum under the ground surface reinforcing layer under the action of the earthquake can be quickly dissipated, and the stratum liquefying risk is reduced.
By adopting the technical scheme, the ground surface reinforcing layer formed by the gravel does not influence the anti-liquefaction performance of the gravel pile under the earthquake action, and compared with the traditional raft foundation, the ground surface reinforcing layer can quickly dissipate the excess pore water pressure in the stratum under the earthquake action and reduce the stratum liquefaction risk; compared with rigid foundations such as raft plates and the like, the ground surface reinforcing layer formed by the gravel has a good drainage channel, and under the action of an earthquake, the ultra-pore water which is locally and rapidly gathered in the foundation can diffuse outwards through the ground surface reinforcing layer formed by the gravel piles and the gravel, so that the pressure of the ultra-pore water in the foundation is dissipated, and the risk of stratum liquefaction is effectively reduced. And the gravel surface reinforcing layer and the gravel pile are made of the same material, and are integrated after construction, so that the water permeability coefficient is the same, and the diffusion of pore water is more convenient.
Optionally, the number of the gravel piles is not less than 4.
Through adopting above-mentioned technical scheme, be no less than 4 gravel piles of quantity can increase the bearing capacity of ground, 4 gravel piles can be the distribution of rectangle array form, cooperate the earth's surface back up coat, form stable bearing structure to guarantee the bearing capacity of ground.
In a second aspect, the present application provides a method for designing a vibroflotation pile composite foundation uniform reinforcement structure, which adopts the following technical scheme:
a design method of a vibroflotation pile composite foundation uniform reinforcement structure comprises the following steps:
s1, simulating vibroflotation of the weak stratum: obtaining relevant stratum parameters based on the geological survey data by adopting a vibroflotation process;
s2, determining a design value of the bearing capacity of the vibroflotation gravel pile composite foundation: calculating a design value which meets the bearing capacity of the foundation according to design requirements;
s3, determining construction parameters of the gravel pile and the thickness of the earth surface reinforcing layer;
s4, carrying out numerical simulation analysis according to the construction parameters, the thickness of the ground surface reinforcing layer and the water permeability coefficient of the ground surface reinforcing layer;
s5, carrying out comprehensive comparative analysis by comparing the design bearing capacity requirement, the anti-liquefaction capacity of the foundation under the earthquake with the design strength, the settlement allowable value and the engineering budget;
s6, if the analysis result in the S5 meets the economic and design technical requirements, entering S7, if not, returning to the S3 for parameter adjustment, and circularly performing the S4 and the S5 until the analysis result meets the design technical requirements and the economic minimum requirements;
and S7, obtaining the optimal arrangement scheme of the gravel pile group, the required minimum pile number and the minimum thickness of the ground surface reinforcing layer.
By adopting the technical scheme, the geological survey parameters are used as basic numerical values, the design values of the gravel piles and the foundation bearing capacity and the thickness of the earth surface reinforcing layer are obtained through reasonable calculation, the quantity of the minimum gravel piles is determined, the thickness of the minimum earth surface reinforcing layer is determined until the construction requirement is met, and the construction cost is saved as the most economical and reasonable scheme.
In summary, the present application includes at least one of the following beneficial technical effects:
1. the ground surface back up coat cooperation gravel pile makes the ground atress more even, and the ground surface back up coat is just like "desktop", rolls in order to increase the closely knit degree of ground surface back up coat, strengthens the interlock effect of gravel pile and stake soil, promotes the bearing capacity. The gravel pile is just like a supported table column, the same load action on the upper part of the foundation is transferred to the table column through the table top, namely the load action is transferred to the gravel pile through the ground surface reinforcing layer, compared with the load action directly acting on the gravel pile, the more the table column is, the more uniform the stress is, the more the overall settlement of the foundation is in synergy and consistency, and the phenomenon of uneven settlement of the composite foundation caused by local weak layers can be effectively weakened;
2. through reasonable planning of the design method for the uniform reinforcement structure of the vibroflotation pile composite foundation, the problem that the construction load is far larger than the design load is solved, the actual construction load is in line with the design load, and the effect of accurately controlling the construction cost is achieved;
3. the earth surface strengthening layer formed by the broken stones can dissipate the water pressure of the excess pore in the foundation, effectively reduces the risk of stratum liquefaction, and the thickness of the earth surface strengthening layer is calculated scientifically and reasonably, so that the effect of accurately controlling the construction cost can be achieved.
4. The improved gravel pile not only considers simulation by a simulation method, but also adds the design of the ground surface reinforcing layer, and after the ground surface reinforcing layer is designed and earthquake simulation parameters are input, the liquefaction degree of the foundation can be predicted more scientifically and accurately due to the fact that the material of the ground surface reinforcing layer is clear and the water permeability coefficient is clear, and therefore the parameters of the gravel pile after final simulation design adjustment can be guaranteed to reach the optimal state with reasonable structure and lowest cost. Therefore, the safety and the reliability of the design scheme are ensured, and the cost is saved to the maximum extent.
Drawings
FIG. 1 is a schematic structural diagram of 4 piles in a unit volume of a weak stratum;
FIG. 2 is a schematic structural diagram of 6 piles in a unit volume of a weak stratum;
FIG. 3 is a schematic structural diagram of 8 piles in a unit volume of a weak stratum;
FIG. 4 is a structural diagram of a plurality of piles in a unit volume weak stratum;
FIG. 5 is a schematic structural diagram of a unit volume of a weak stratum provided with a ground surface reinforcing layer;
FIG. 6 is a schematic diagram of a thickened surface reinforcing layer;
fig. 7 is a flow chart of a design method of a vibroflotation pile composite foundation uniform reinforcement structure.
Description of reference numerals: 1. a weak formation per unit volume; 2. gravel piles; 3. and (5) a ground surface reinforcing layer.
Detailed Description
The present application is described in further detail below with reference to figures 1-7.
The embodiment of the application discloses even reinforced structure of vibroflotation pile composite foundation.
The weak formation 1 per unit volume is taken as an example below: referring to fig. 1, four gravel piles 2 are arranged in a unit volume weak stratum 1, the gravel piles 2 are distributed at four corners of the unit volume weak stratum 1 in a rectangular array shape, and a composite foundation is formed by the gravel piles 2 to improve the bearing performance of the foundation.
Referring to fig. 2 to 4, in order to improve the bearing performance of the weak stratum 1 in unit volume, or improve the requirement of earthquake fortification or the liquefaction resistance of the foundation, the number of the gravel piles 2 is increased in unit volume, and the design requirement is met by controlling the distance between the adjacent gravel piles 2, or increasing the pile diameter of a single gravel pile 2, or adjusting the arrangement of the whole gravel pile 2 pile group.
Referring to fig. 5, a ground surface reinforcing layer 3 is paved on the soft stratum 1 in unit volume, the ground surface reinforcing layer 3 is composed of gravel, and the ground surface reinforcing layer 3 is connected with the tops of all gravel piles 2; because pores exist among the crushed stones, the ground surface strengthening layer 3 made of the rolled crushed stones has good natural drainage channels, the water pressure of the super pores in the foundation can be dissipated, and the risk of stratum liquefaction is effectively reduced.
Bearing capacity that the earth's surface back up coat 3 will receive is transmitted for each gravel pile 2, strengthens whole composite foundation wholeness, avoids or weakens the inhomogeneous settlement problem of composite foundation that local weak stratum brought.
The embodiment of the application also discloses a design method of the vibroflotation pile composite foundation uniform reinforcement structure.
Referring to fig. 6 and 7, the following steps are included:
s1, simulating vibroflotation of the weak stratum: obtaining relevant stratum parameters based on the geological survey data by adopting a vibroflotation process;
s2, determining the design value of the bearing capacity of the vibroflotation gravel pile 2 composite foundation: calculating a design value which meets the bearing capacity of the foundation according to design requirements;
s3, determining construction parameters of the gravel pile 2 and the thickness of the earth surface reinforcing layer 3; the key construction design parameters of the gravel pile 2 comprise pile diameter, pile distance, pile number, seismic requirements and the like;
s4, carrying out numerical simulation analysis according to the construction parameters, the thickness of the earth surface reinforcing layer 3 and the water permeability coefficient of the earth surface reinforcing layer 3;
s5, carrying out comprehensive comparative analysis by comparing the design bearing capacity requirement, the anti-liquefaction capacity of the foundation under the earthquake with the design strength, the settlement allowable value and the engineering budget;
s6, if the analysis result in the S5 meets the economic and design technical requirements, entering S7, if not, returning to the S3 for parameter adjustment, and circularly performing the S4 and the S5 until the analysis result meets the design technical requirements and the economic minimum requirements; the design technology needs to meet different working conditions, for example, the upper structure is a dam or a building, and different design requirements can be generated.
And S7, obtaining the optimal arrangement scheme of the gravel pile 2 group, the required minimum pile number and the minimum thickness of the ground surface reinforcing layer 3.
The most important invention points of the application are two, the first is that the earth surface strengthening layer 3 which has the same water permeable function and is made of the gravel materials is designed at the top of the gravel pile 2, the design enables the water to be rapidly discharged upwards in the vertical direction through the gravel pile 2 in the coming earthquake, the rapid pressure relief in the horizontal direction is carried out through the earth surface strengthening layer 3, and finally the water is discharged from the water permeable stratum on the same layer of the earth surface strengthening layer 3, so that the effect of rapidly dissipating the pressure of the underground water is achieved, the generation of stratum liquefaction can be avoided, and the safety of the building is ensured. In addition, it is also possible that, at the time of an earthquake, groundwater is rapidly transferred from the ground above/below the surface reinforcing layer 3 up/down through the gravel piles 2 to a highly water-permeable ground layer capable of rapid drainage, so as to rapidly dissipate the excess pore water pressure of the vibroflotation layer.
The second invention is to improve the design method of the gravel pile 2. The existing design of the gravel pile 2 mainly depends on engineering experience to be developed, the detection means after construction is finished is single, the pile body cannot be fully covered, and the safety factor of the structure is continuously increased in the design stage, so that the gravel pile 2 is frequently designed to be a conservative design scheme with larger diameter, deeper depth and smaller pile spacing, and the cost is greatly increased, and unnecessary materials and workload are wasted. The improved gravel pile 2 is simulated by means of simulation, the design of the earth surface reinforcing layer 3 is added, and after the earth surface reinforcing layer 3 is designed and earthquake simulation parameters are input, the liquefaction degree of the foundation under the action of a designed earthquake can be predicted more accurately due to the fact that key construction parameters such as the geometric dimension, the material property and the water permeability coefficient of the earth surface reinforcing layer 3 are clear, and therefore the condition that the construction parameters of the gravel pile 2 after final simulation design adjustment reach the optimal state with reasonable structure, lowest cost and intensive efficiency is guaranteed. Therefore, the safety and the reliability of the design scheme are ensured, and the maximum cost is also ensured.
The embodiments of the present invention are preferred embodiments of the present application, and the scope of protection of the present application is not limited by the embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.
Claims (5)
1. The utility model provides an even reinforced structure of vibroflotation pile composite foundation which characterized in that: the gravel pile comprises a gravel pile (2) and a ground surface reinforcing layer (3) which is made of a water-permeable material through rolling, wherein the gravel pile (2) is positioned in a composite stratum, the ground surface reinforcing layer (3) covers the ground surface of the composite stratum, and the ground surface reinforcing layer (3) is connected with the top of the gravel pile (2).
2. The vibroflotation pile composite foundation uniform reinforcement structure as claimed in claim 1, wherein: the ground surface reinforcing layer (3) is made of crushed stone, and the crushed stone ground surface reinforcing layer (3) naturally has a drainage channel, so that the super-pore water pressure of the lower liquefiable stratum can be quickly dissipated under the action of an earthquake, and the stratum liquefying risk is reduced.
3. The vibroflotation pile composite foundation uniform reinforcement structure as claimed in claim 1, wherein: the gravel piles (2) are arranged in number of not less than 4.
4. A design method of a vibroflotation pile composite foundation uniform reinforcement structure is characterized by comprising the following steps: the method comprises the following steps:
s1, simulating vibroflotation of the weak stratum: obtaining relevant stratum parameters based on the geological survey data by adopting a vibroflotation process;
s2, determining the design value of the bearing capacity of the vibroflotation gravel pile (2) composite foundation: calculating a design value which meets the bearing capacity of the foundation according to design requirements;
s3, determining construction parameters of the gravel pile (2) and the thickness of the earth surface reinforcing layer (3);
s4, carrying out numerical simulation analysis according to the construction parameters, the thickness of the earth surface reinforcing layer (3) and the water permeability coefficient of the earth surface reinforcing layer (3);
s5, carrying out comprehensive comparative analysis by comparing the design bearing capacity requirement, the anti-liquefaction capacity of the foundation under the earthquake with the design strength, the settlement allowable value and the engineering budget;
s6, if the analysis result in the S5 meets the economic and design technical requirements, entering S7, if not, returning to the S3 for parameter adjustment, and circularly performing the S4 and the S5 until the analysis result meets the design technical requirements and the economic minimum requirements;
and S7, obtaining the optimal arrangement scheme of the gravel pile (2) group, the required minimum pile number and the minimum thickness of the ground surface reinforcing layer (3).
5. The design method of the vibroflotation pile composite foundation uniform reinforcement structure according to claim 4, characterized in that: the key construction design parameters of the gravel pile (2) in the step S3 comprise pile diameter, pile distance and pile number.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101463599A (en) * | 2009-01-16 | 2009-06-24 | 湖南大学 | Bidirectional reinforcing and water drainage reinforcing means for highway soft soil foundation |
| CN103046530A (en) * | 2012-12-31 | 2013-04-17 | 中国建筑西南勘察设计研究院有限公司 | Gravel pile and plain concrete pile combined composite foundation |
| CN202936772U (en) * | 2012-11-14 | 2013-05-15 | 河南省电力勘测设计院 | Long-short vibro-replacement stone column for treating badly liquefied foundation |
| CN103590391A (en) * | 2013-11-27 | 2014-02-19 | 温州宏源水电建设有限公司 | Cement-fly-ash-gravel pile foundation reinforcing construction method |
| CN104153388A (en) * | 2014-08-22 | 2014-11-19 | 中国建筑西南勘察设计研究院有限公司 | Composite foundation and construction method thereof |
| CN109778831A (en) * | 2018-11-28 | 2019-05-21 | 中交一公局桥隧工程有限公司 | Ram-compaction gravel piles reinforce Artifical Fill Ground construction |
| CN112921946A (en) * | 2021-01-28 | 2021-06-08 | 武汉大学 | Reinforcing system and reinforcing method for liquefiable site reinforced gravel pile composite foundation embankment |
-
2022
- 2022-01-10 CN CN202210023822.6A patent/CN114293533A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101463599A (en) * | 2009-01-16 | 2009-06-24 | 湖南大学 | Bidirectional reinforcing and water drainage reinforcing means for highway soft soil foundation |
| CN202936772U (en) * | 2012-11-14 | 2013-05-15 | 河南省电力勘测设计院 | Long-short vibro-replacement stone column for treating badly liquefied foundation |
| CN103046530A (en) * | 2012-12-31 | 2013-04-17 | 中国建筑西南勘察设计研究院有限公司 | Gravel pile and plain concrete pile combined composite foundation |
| CN103590391A (en) * | 2013-11-27 | 2014-02-19 | 温州宏源水电建设有限公司 | Cement-fly-ash-gravel pile foundation reinforcing construction method |
| CN104153388A (en) * | 2014-08-22 | 2014-11-19 | 中国建筑西南勘察设计研究院有限公司 | Composite foundation and construction method thereof |
| CN109778831A (en) * | 2018-11-28 | 2019-05-21 | 中交一公局桥隧工程有限公司 | Ram-compaction gravel piles reinforce Artifical Fill Ground construction |
| CN112921946A (en) * | 2021-01-28 | 2021-06-08 | 武汉大学 | Reinforcing system and reinforcing method for liquefiable site reinforced gravel pile composite foundation embankment |
Non-Patent Citations (2)
| Title |
|---|
| 孙林娜: "《中国优秀博硕士学位论文全文数据库（博士）》" * |
| 孙林娜: "复合地基沉降及按沉降控制的优化设计研究", 《中国优秀博硕士学位论文全文数据库（博士）》 * |
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