Device and method for treating soft soil foundations

Abstract

A device and a method for treating soft soil foundations, the device comprises: a drainage plate (4), a water collection well (7), and a pressurizing drainage pipe (6), the pressurizing drainage pipe (6) is connected to the bottom of the drainage plate and the bottom of the water collection well through pipelines; a pressurizing module comprises: film (12), the film (12) is impermeable and covers the soft soil foundation; a pile-loading body (13), the pile-loading body (13) is arranged on the film; air compressor (1) has a pressurizing end with a space below the film to make a soil layer of the soft soil foundation below the film under an air pressure higher than the atmospheric pressure, so that the underground water discharge process can be started.

Claims

1. A device for treating soft soil foundations comprising: a drainage plate, which is vertically inserted into a soft soil foundation and has a vertical internal gap and a side pore; a water collection well with a depth from 10 to 20 meters, wherein the level of its bottom is lower than the lowest position of the drainage plate; a pressurizing drainage pipe, which is connected to the bottom of the drainage plate and the bottom of the water collection well through pipelines; and a pressurizing module comprising: a film, which is impermeable and covers the soft soil foundation; a pile-loading body, which is arranged on the film; an air-permeable layer between the film and the soft soil foundation; a space between the film and the air-permeable layer, wherein an air pressure is constantly maintained at a level higher than the atmospheric pressure; and an air compressor, which has a pressurizing end inserted to the space below the film.

2. The device for treating soft soil foundations according to claim 1, wherein one end inserted into the soft soil foundation of the drainage plate is provided with a pile shoe.

3. The device for treating soft soil foundations according to claim 2, wherein one end of the pressuring drainage pipe is communicated with a water accommodating space in the pile shoe.

4. The device for treating soft soil foundations according to claim 1, wherein a depth of the drainage plate inserted into the soft soil foundation is at least the altitude of a water column corresponding to air pressure below the film.

5. The device for treating soft soil foundations according to claim 4, wherein the depth of the drainage plate inserted into the soft soil foundation is 15 meters.

6. A method for treating soft soil foundations with a device, the device comprising: a drainage plate, which is vertically inserted into a soft soil foundation and has a vertical internal gap and a side pore; a water collection well with a depth from 10 to 20 meters, wherein the level of its bottom is lower than the lowest position of the drainage plate; a pressurizing drainage pipe, which is connected to the bottom of the drainage plate and the bottom of the water collection well through pipelines; and a pressurizing module comprising: a film, which is impermeable and covers the soft soil foundation; a pile-loading body, which is arranged on the film; an air-permeable layer between the film and the soft soil foundation; a space between the film and the air-permeable layer, wherein an air pressure is constantly maintained at a level higher than the atmospheric pressure; and an air compressor, which has a pressurizing end inserted to the space below the film; the method comprising the following steps: arranging the drainage plate, the water collection well, and the pressurizing drainage pipe in the soft soil foundation to be treated; arranging a pressurizing module on the soft soil foundation to be treated; and starting the air compressor to make the space below the film under an air pressure higher than the atmospheric pressure so as to start the underground water discharge process, wherein a weight of the pile-loading body is borne by the film and a maximum air pressure below the film is kept in balance with the weight of the pile-loading body.

7. The method according to claim 6, wherein the method further comprises: After the drainage process is finished, stopping the operation of the air compressor to make the pile-loading body compress the unsaturated soft soil foundation to complete soil consolidation.

8. The method according to claim 6, wherein a thick soil layer of 2 meters is adopted as the pile-loading body.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of a device for treating soft soil foundations.

DETAILED DESCRIPTION OF THE INVENTION

(2) For a better understanding of the technical issues to be settled, technical solutions, and advantages of the invention, the invention is expounded below in combination with the accompanying drawings and specific embodiments. In the following description, specific configurations and characteristic details of components are only provided to assist in a comprehensive understanding of the embodiments of the invention. Thus, those skilled in the art can make various changes and modifications on the following embodiments without deviating from the scope and spirit of the invention. Besides, for the sake of a clear and brief description, the descriptions on known functions and structures are omitted.

(3) It should be understood that “one embodiment” or “an embodiment” mentioned throughout the specification means that specific characteristics, structures, or properties related to the embodiment are included in at least one embodiment of the invention. Thus, “in one embodiment” or “in an embodiment” throughout the whole specification does not necessarily refer to the same embodiment. Besides, these specific characteristics, structures, or properties can be arbitrarily combined in one or more embodiments.

(4) In all embodiments of the invention, it should be understood that the sequence numbers of the following processes do not mean the execution order. The execution order of the processes should be determined by the functions and internal logic of the processes, and should not limit any implementation processes of the embodiments of invention.

(5) It should be understood that the term “and/or” in this article is only an association relationship for describing associated objects and indicates that there are three relationships. For instance, A and/or B indicates that A exists independently, A and B exist simultaneously, and B exists independently. Besides, the character “/” in this article generally indicates that the associated objects are in an “or” relationship.

(6) In the embodiments of this application, it should be understood that “B corresponding to A” indicates that B is associated with A, and B can be determined according to A. It should be further understood that B is not only determined according to A, but also determined according to A and/or other information.

(7) Embodiments

(8) The invention particularly relates to a device and method for treating soft soil foundations.

(9) As shown in FIG. 1, the device for treating soft soil foundations comprises an air compressor 1, an air inflation pipe 2, an air-permeable layer 3, drainage plates 4, pile shoes 5, a pressurizing drainage pipe 6, a water collection well 7, a water pump 8, a water level controller 9, a drainage pipe 10, a ground 11, a film 12, a pile-loading body 13, and other operating modules.

(10) The operating modules are respectively expounded as follows:

(11) Drainage Plate

(12) The drainage plates are vertical drainage components which are inserted into a soft soil foundation and have vertical internal gaps and side pores to facilitate water in soil to enter the drainage plates. Although the drainage plates in the invention are described as drainage plate in consideration of a common name in the industry, it should be understood that drainage components having vertical and side drainage passages can be used as equivalent replacements of the drainage plates of the invention.

(13) A typical drainage plate 4 may be a common plastic drainage plate in projects. In order to improve drainage efficiency and easily insert the drainage plates into the soil, the pile shoes 5 are arranged at one ends of the drainage plates 4.

(14) The distribution principle of the drainage plates is generally based on the area of a soft soil foundation to be treated, and the plastic drainage plates are distributed on the same plane in different spaced and arrayed manners. It should be understood that in spite of various planar arrangement manners, the plastic drainage plates 4 should be reasonably arranged based on the drainage radiuses of the plastic drainage plates 4.

(15) The depth of the drainage plates inserted into the soil is determined according to the treatment needs of the foundation. However, the depth of the drainage plates inserted into the soft soil foundation is at least the altitude of a water column corresponding to the air pressure below the film.

(16) In an illustrative embodiment of the invention, the insertion depth of the plastic drainage plates is 15 m, and the planar spacing of the plastic drainage plates is 2 m.

(17) Pressurizing Drainage Pipe

(18) The pressurizing drainage pipe 6 is communicated with the bottoms of the drainage plates 4 and the bottom of the water collection well 7 (which will be expounded hereinbelow). Typically, the pressurizing drainage pipe 6 is a slim pipe having a diameter of 5 mm and has one end extending into the pile shoes 5 via the insides of the drainage plates 4 and the other end extending to the bottom of the water collection well 7.

(19) Typically, water accommodating spaces are configured in the pile shoes 5 and are communicated with the bottom of the water collection well 7 through one end of the pressurizing drainage pipe 6.

(20) The pressurizing drainage pipe 6 allowing a plurality of drainage plates 4 to be collected is converged into the water collection well 7 through a pipe network.

(21) Water Collection Well

(22) The water collection well 7 is arranged close to the soft soil foundation to be treated. Typically, the water collection well 7 is formed in a drilling manner and/or a manual hole digging manner.

(23) Furthermore, a facility for discharging water to the outside is arranged at the bottom of the water collection well 7. Typically, the facility is a drainage facility provided with the water pump 8 and the drainage pipe 10 connected with the water pump 8. Underground water in the water collection well 7 is discharged by the drainage facility out of the soft soil foundation to be treated.

(24) Furthermore, the drainage facility further includes the water level controller 9 used for detecting and controlling the preset depth of the underground water level in the water collection well 7, and the preset depth is generally used for determining start and stop conditions of the water pump.

(25) For instance, the preset depth is a preset range value. When the underground water level in the water collection well 7 exceeds the upper limit of the preset value, the water level controller 9 controls the drainage facility to operate to lower the underground water level in the water collection well 7 to the lower limit of the preset value, and then controls the drainage facility to stop drainage operation.

(26) In the illustrative embodiment of the invention, the depth of the water collection well 7 is 15 m.

(27) Pressurization Module

(28) The pressurization module is used for pressurizing underground water in the soft soil foundation to make the underground water in the soft soil foundation be discharged into the water collection well 7 via the pressurizing drainage pipe 6 under a high pressure.

(29) The pressurization module includes the air-permeable layer 3, the film 12, the air compressor 1, and the pile-loading body 13.

(30) Wherein, the air-permeable layer is arranged on the ground 11, having the drainage plates 4 inserted therein and a pressurizing drainage pipe network laid thereon, of the soft soil foundation. Typically, the air-permeable layer 3 is a sand mat which can protect the drainage facility and has good air permeability. The air-permeable layer 3 further has an effect of protecting the intactness of the film 12 in contact with the air-permeable layer.

(31) The film 12 covers the soft soil foundation to guarantee the air impermeability of the soft soil foundation to be treated against the outside.

(32) The air compressor 1 has a pressurizing end communicated with the air-permeable layer 3 and carries out pressurization below the film 12 after being started.

(33) The pile-loading body 13 is uniformly arranged on the film 12. After the air compressor 1 is started, the air pressure below the air-proof film 12 is increased, and the weight of the pile-loading body is borne by the film, so that the maximum air pressure below the film is kept in balance with the weight of the pile-loading body 13. Typically, in the illustrative embodiment of the invention, a thick soil layer of 2 m is adopted as the pile-loading body 13.

(34) In this way, in the operating state of the air compressor 1, the drainage plates 4 and the air-permeable layer 3 below the air-proof film 12 are under an air pressure higher than the atmospheric pressure, the pressure of pore water in a soil layer of the soft soil foundation is increased, and the underground water is forced to flow into the water collection well 7 via the pressurizing drainage pipe 6, so that the drainage is started; and the underground water in the soft soil foundation continuously flows into the water collection well 7 via the pressurizing drainage pipe and is discharged by the drainage facility. When the underground water level is lowered to meet the design requirement, the air compressor stops operating, and at this moment, the soil is unsaturated, so that the compression and consolidation process of the soil can be rapidly completed under the effect of the pile-loading body 13.

(35) That is, in the whole drainage process, the soil is still in a high-pressure state after moisture in the soil is discharged, and the bearing state of the soil layer is not obviously changed, so that the drainage process will not be as slow as the drainage process, accompanied with soil consolidation, of a vacuum preloading method. After the air compressor stops operating, the high-pressure state is eliminated, and the weight of the pile-loading body 13 acts on foundation soil having the underground water discharged, so that the pressurization and compression process of the unsaturated foundation soil can be completed rapidly.

(36) That is, in the device for treating soft soil foundations of the invention, the drainage process and the compressive deformation and consolidation process of the soil are mutually independent.

(37) The method for treating soft soil foundations is further expounded below and comprises:

(38) S1: drainage plates 4, a water collection well 7, and a pressurizing drainage pipe 6 are arranged in a soft soil foundation to be treated;

(39) S2: a pressurization module which at least includes an air compressor 1, a film 12, and a pile-loading body 13 is arranged on the soft soil foundation to be treated; and

(40) S3: the air compressor 1 is started to make a soil layer of the soft soil foundation below the film 12 under an air pressure higher than the atmospheric pressure so as to start drainage.

(41) Furthermore, the method further comprises:

(42) S4: after the drainage is finished, the air compressor 1 stops operating to make the pile-loading body 13 compress the unsaturated soft soil foundation to complete soil consolidation.

(43) Furthermore, the pressurization module further includes an air-permeable layer arranged on a ground 11.

(44) It should be finally noted that the above embodiments are only used for explaining the technical solutions of the invention instead of limiting the technical solutions of the invention. Although the invention is expounded with reference to the above embodiments, those skilled in the art can still make modifications on the technical solutions recorded in the above embodiments or equivalent replacements on partial technical features of the technical solutions without causing the deviation of the essence of the corresponding technical solution from the spirit and scope of the technical solutions of the embodiments of the invention.