A drainage system suitable for preloading and drainage consolidation of high-mud content sand cushion

Abstract

The utility model discloses a drainage system suitable for high mud content sand cushion layer preloading drainage consolidation, including a sand cushion layer laid on the upper part of the soft soil layer, a loading layer laid on the upper part of the sand cushion layer and an assembled water collection manhole with the bottom located in the soft soil layer, a first geotextile is laid between the sand cushion layer and the soft soil layer, and a second geotextile is laid between the sand cushion layer and the loading layer; vertical drainage boards are inserted inside the soft soil layer and the sand cushion layer, a water collection pipe connected to the assembled water collection manhole is horizontally arranged in the soft soil layer, and a plurality of drainage pipes are longitudinally arranged in the sand cushion layer, and the drainage pipe and the water collection pipe are connected through a joint; the wall of the drainage pipe is a spiral corrugated structure with the same pitch and waveform and continuous direction, and the cross section of the spiral corrugated structure is circular. HDPE spiral corrugated pipe is used as a drainage pipe to replace the drainage blind ditch, and the mud content of the sand cushion layer can be enlarged to less than 10% to 15% of the mud content. At the same time, it can be reused or serve as a later underground drainage structure after the settlement is completed.

Description

Technical Field

[0001] The utility model relates to the field of soft soil foundation and land reclamation treatment construction, and more specifically, to a drainage system suitable for preloading and drainage consolidation of a sand cushion layer with high mud content. Background Art

[0002] The preloading drainage consolidation method is to apply load preloading to the foundation, and at the same time take a series of measures to accelerate the discharge of water in the soil, reduce the pores of the soil, and gradually consolidate, so as to achieve the purpose of improving the bearing capacity of the soft soil foundation and reducing settlement. It mainly includes preloading load design and foundation drainage, that is, according to the later use load and the nature of the foundation soil, the construction period requirements and the impact on adjacent buildings, the preloading system and drainage system are reasonably designed. Among them, the drainage system is the guarantee that the free water between the soil particles can be drained smoothly and the foundation can be consolidated quickly, mainly including vertical drainage system and horizontal drainage system. For thicker soft soil layers, vertical drainage bodies must be used to shorten the drainage path and ensure the permeability coefficient of the horizontal drainage body to speed up the drainage speed and ensure the effect of strengthening the foundation. The specific drainage system should be based on the soil conditions of the foundation, the thickness of the soft soil layer, the quality of the coarse sand in the project location, etc.

[0003] In the design of drainage system, coarse sand and medium coarse sand with good water permeability are generally used as horizontal drainage channels. Affected by the geographical location and transportation conditions of the project, through the investigation of surrounding sand and gravel plants, it is found that there are very few sand fields with mud content (less than 5% required by the specification) and gradation that meet the requirements of the specification, and the average daily output is less than 2,000 tons, which is far lower than the daily average demand (average daily demand of 8,000 tons / day). After relevant investigations and experiments, with the consent of the owner and the designer, the mud content and gradation of the medium coarse sand are adjusted, but it is necessary to ensure its horizontal drainage efficiency and ensure the project schedule. Utility Model Content

[0004] The purpose of the utility model is to provide a drainage system suitable for preloading and drainage consolidation of sand cushion layers with high mud content. HDPE spiral corrugated pipes are used as drainage pipes to replace drainage blind ditches. The mud content of the sand cushion layer can be enlarged to less than 10% to 15%. At the same time, after the settlement is completed, it can be reused or serve as a later underground drainage structure.

[0005] The technical solution adopted by the utility model to solve this technical problem is: providing a drainage system suitable for high-mud content sand cushion layer preloading and drainage consolidation, comprising a sand cushion layer laid on the upper part of the soft soil layer, a loading layer laid on the upper part of the sand cushion layer and an assembled water collection manhole with the bottom located in the soft soil layer, the top of the assembled water collection manhole extends upward to above the loading layer, a first geotextile is laid between the sand cushion layer and the soft soil layer, and a second geotextile is laid between the sand cushion layer and the loading layer;

[0006] A plurality of vertical drainage boards are inserted inside the soft soil layer and the sand cushion layer, a water collecting pipe connected to the assembled water collecting manhole is horizontally arranged in the soft soil layer, and a plurality of drainage pipes are longitudinally arranged in the sand cushion layer, and the drainage pipes are connected to the water collecting pipes through joints;

[0007] The wall of the drainage pipe is in a spiral corrugated structure with the same pitch and waveform and a continuous direction, and the cross section of the spiral corrugated structure is circular.

[0008] Preferably, the drainage system applicable to high mud content sand cushion preloading drainage consolidation, the assembled water collection manhole comprises a concrete bottom plate and circular prefabricated parts, and a plurality of the circular prefabricated parts are vertically stacked on the concrete bottom plate;

[0009] A fully automatic submersible pump is installed inside the assembled water collection manhole. The fully automatic submersible pump includes a water delivery pipe, and the water delivery pipe extends upward to the outside of the assembled water collection manhole.

[0010] Preferably, in the drainage system suitable for preloading and drainage consolidation of sand cushion layers with high mud content, the drainage pipe is wrapped with a layer of non-woven geotextile.

[0011] Preferably, in the drainage system suitable for high-mud content sand cushion preloading drainage consolidation, both ends of the water collecting pipe are 10 cm lower than the surface of the soft soil layer and are arranged toward the assembled water collecting manhole with a slope of 0.5%.

[0012] Preferably, in the drainage system suitable for preloading drainage consolidation of high-mud content sand cushion layers, the drainage pipe is set 10 cm above the surface of the soft soil layer, and the horizontal drainage pipes are arranged at a spacing of 12 m.

[0013] Preferably, in the drainage system suitable for preloading drainage consolidation of high-mud content sand cushion layers, the vertical drainage boards are plastic drainage boards, and the vertical drainage boards are arranged in a square shape with a size of 1.0m*1.0m.

[0014] Preferably, in the drainage system suitable for preloading and drainage consolidation of high-mud content sand cushion layers, the joint is a tee joint or a 90° elbow joint.

[0015] The utility model at least has the following beneficial effects:

[0016] 1. Efficiency

[0017] Through this drainage system, the water flow path is shortened, the horizontal drainage efficiency is accelerated, the consolidation period is shortened, and the construction is convenient. During the construction process, there is no need to reconsider setting the hydraulic slope on the drainage cushion layer.

[0018] 2. Economical

[0019] By providing this system, the mud content of the drainage sand cushion layer can be increased and the grading requirements of the sand cushion layer can be reduced, thereby reducing the procurement cost of the sand cushion layer.

[0020] 3. Scientificity

[0021] After the soft soil stratum load is loaded to the design load, the amount of water discharged by the stratum during the settlement process can be accurately measured by using the submersible pump + water meter in the manhole, providing favorable data support for verifying the foundation settlement.

[0022] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural schematic diagram of a drainage system suitable for preloading and drainage consolidation of a sand cushion with high mud content in the utility model;

[0024] Figure 2 This is an axonometric diagram of structure A in a drainage system suitable for preloading and drainage consolidation of a high-mud content sand cushion layer in the utility model;

[0025] Figure 3 This is a front view of structure A in a drainage system suitable for preloading and drainage consolidation of a sand cushion with high mud content in the utility model;

[0026] Figure 4 It is a side view of structure A in a drainage system suitable for preloading and drainage consolidation of a sand cushion with high mud content in the utility model;

[0027] Figure 5 This is an axonometric diagram of the B structure in a drainage system suitable for preloading and drainage consolidation of a high-mud content sand cushion layer in the utility model;

[0028] Figure 6 This is a front view of the B structure in the drainage system suitable for preloading and drainage consolidation of a sand cushion with high mud content in the utility model;

[0029] Figure 7 It is a side view of structure B in a drainage system suitable for preloading and drainage consolidation of a sand cushion with high mud content in the utility model;

[0030] Figure 8 This is a structural diagram of an assembled water collection manhole in a drainage system suitable for preloading and drainage consolidation of a high-mud content sand cushion layer in the utility model;

[0031] Explanation of the accompanying drawings: 1. soft soil layer, 2. sand cushion layer, 3. loading layer, 4. assembled water collection manhole, 5. first geotextile, 6. second geotextile, 7. vertical drainage board, 8. water collection pipe, 9. drainage pipe, 10. joint, 11. fully automatic submersible pump, 12. water pipe, 13. non-woven geotextile, 14. concrete base plate, 15. circular prefabricated part. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0033] The following description is used to disclose the utility model so that those skilled in the art can implement the utility model. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the utility model defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the utility model.

[0034] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0035] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0036] like Figure 1-7 As shown, a preferred embodiment of the utility model provides a drainage system suitable for high mud content sand cushion preloading drainage consolidation, comprising a sand cushion 2 laid on the upper part of a soft soil layer 1, a loading layer 3 laid on the upper part of the sand cushion 2 and an assembled water collection manhole 4 with the bottom located in the soft soil layer 1, the top of the assembled water collection manhole 4 extends upward to above the loading layer 3, a first geotextile 5 is laid between the sand cushion 2 and the soft soil layer 1, and a second geotextile 6 is laid between the sand cushion 2 and the loading layer 3;

[0037] Several vertical drainage boards 7 are inserted inside the soft soil layer 1 and the sand cushion layer 2. A water collecting pipe 8 connected to the assembled water collecting manhole 4 is horizontally arranged in the soft soil layer 1. A plurality of drainage pipes 9 are longitudinally arranged in the sand cushion layer 2. The drainage pipes 9 are connected to the water collecting pipes 8 through joints 10. In this embodiment, a preferred implementation scheme is to use glue to bond the drainage pipes 9, water collecting pipes 8 and joints 10 to ensure the strength of the interface 10 and avoid the interface 10 from falling off due to uneven settlement of the stratum. The diameter of the drainage pipe 9 is 125mm, and the spacing is 12m. The diameter of the water collecting pipe 8 is 125mm.

[0038] The wall of the drain pipe 9 is a spiral corrugated structure with the same pitch and waveform and continuous direction. The cross section of the spiral corrugated structure is circular. The drain pipe 9 is made of high-density polyethylene material and processed into a spiral corrugated pipe structure. The material strength and structural strength ensure that the radial deformation of the drain pipe 9 is small under the action of external force. When subjected to uneven settlement, the drain pipe 9 undergoes deformation to adapt to the settlement. In this embodiment, a preferred implementation scheme is that the drain pipe 9, the water collecting pipe 8 and the joint 10 are all made of HDPE material. The drain pipe 9 has a 70% pore part and a 30% non-void part, and the cross-sectional opening area is 40%. It can withstand a load of more than 10Ton / ㎡ and the pipe deformation rate is less than 8%. It is light in weight and has good acid and alkali resistance. It will not be degraded by chemicals or soil bacteria.

[0039] In this embodiment, a preferred implementation scheme is that the system can also be installed with detection equipment such as pressure gauges, settlement plates, inclinometers and groundwater level observation wells, and the pressure gauge is used to monitor the changes in pore water pressure and soil pressure in the soil, and the settlement plates and inclinometers are used to monitor vertical and horizontal displacements. By regularly observing the observation data of the pressure gauges, settlement plates, inclinometers and groundwater level observation wells installed on site, the maps of the observed physical quantities and spatial distribution characteristics and the process curves of the observed physical quantities are drawn, and finally the Asaoka and Hyperbolic methods are used to fit and predict the settlement, and the consolidation degree and the expected settlement value are double-verified to ensure the settlement effect. The monitoring data and related information are systematically collected and managed through the computer database, and the monitoring data can be obtained anytime and anywhere through the network browser. At the same time, the early warning value can be set to warn when the foundation settlement rate is too fast.

[0040] Furthermore, the drainage system suitable for high-mud-content sand cushion loading preloading drainage consolidation, the assembled water collection manhole 4 includes a concrete base plate 14 and a circular prefabricated part 15, and a plurality of the circular prefabricated parts 15 are vertically stacked on the concrete base plate 14; in the present embodiment, a preferred implementation scheme is that the assembled water collection manhole 4 adopts a prefabricated assembled structure, the bottom section adopts a 25 cm rear concrete base plate 14, and the wall body adopts a circular prefabricated part 15 with a diameter of 1.0 m and a height of 1.0 m, and is connected by a flat-end interface.

[0041] A fully automatic submersible pump 11 is installed inside the assembled water collection manhole 4, and the fully automatic submersible pump 11 includes a water delivery pipe 12, and the water delivery pipe 12 extends upward to the outside of the assembled water collection manhole 4. In this embodiment, a preferred implementation scheme is that the water delivery pipe 12 is externally connected to the drainage system, and a water pump can be installed on the drainage pipe 9. When the water level in the water collection manhole 4 is too high, the fully automatic submersible pump 11 will automatically start and discharge water to the outside of the assembled water collection manhole 4 through the water delivery pipe 12. At the same time, the water pump installed on the drainage pipe 9 will automatically record the drainage volume.

[0042] Furthermore, in the drainage system suitable for high-mud content sand cushion preloading drainage consolidation, the drainage pipe 9 is wrapped with a layer of non-woven geotextile 13 to prevent sand and gravel from flowing into the drainage pipe 9 and causing blockage of the drainage pipe 9. In this embodiment, a preferred implementation scheme is that the weight of the non-woven geotextile 13 is 200g / ㎡.

[0043] Furthermore, in the drainage system suitable for high mud content sand cushion preloading drainage consolidation, both ends of the water collecting pipe 8 are 10 cm lower than the surface of the soft soil layer 1, and are arranged with a slope of 0.5% toward the assembled water collecting manhole 4. Setting a certain slope can speed up the flow of water to the assembled water collecting manhole 4.

[0044] Furthermore, in the drainage system suitable for preloading and drainage consolidation of a high-mud content sand cushion layer, the drainage pipe 9 is set 10 cm above the surface of the soft soil layer 1, and the horizontal drainage pipes 9 are arranged at a spacing of 12 m.

[0045] Furthermore, in the drainage system suitable for preloading and drainage consolidation of high-mud content sand cushion layers, the vertical drainage boards 7 are plastic drainage boards, and the vertical drainage boards 7 are arranged in a square shape with a spacing of 1m*1m.

[0046] Furthermore, in the drainage system suitable for high mud content sand cushion preloading drainage consolidation, the joint 10 is a tee joint or a 90° elbow joint. In this embodiment, a preferred implementation is as follows: Figure 2-4 As shown, the water collecting pipe 8 in the marginal soil is connected to the drainage pipe 9 through a 90° elbow joint 10 and a tee joint 10, as shown in FIG. Figure 5-7As shown, the water collecting pipe 8 in the middle part is connected to the drainage pipe 9 through two three-way joints 10.

[0047] The utility model also provides a construction method for a drainage system suitable for preloading and drainage consolidation of a high-mud content sand cushion layer, and the specific steps are as follows:

[0048] Step 1: After the site is cleared and leveled to 0 elevation and rolled to 95% compaction, the surveyor will mark the positions of the assembled water collection manhole 4, vertical drainage board 7, drainage pipe 9 and water collection pipe 8 according to the designed spacing;

[0049] Step 2: According to the layout position, the vertical drainage board 7 is laid out in a square with a spacing of 1m*1m, the soft soil layer 1 is excavated to the design elevation, and the assembled water collection manhole 4 with a diameter of 1000mm is placed. The height of the assembled water collection manhole 4 can be continuously increased to adapt to the continuous loading. At the same time, -10cm is dug from the elevation of the soft soil layer 1, and the water collection pipe 8 is installed in the marginal soil and laid toward the assembled water collection manhole 4 with a slope of 0.5%;

[0050] Step 3: Lay the first geotextile 5, make artificial grooves at the corresponding positions of the vertical drainage board 7 and the joint 10, install the drainage pipe 9 wrapped with the non-woven geotextile 13 at an elevation of 10 cm from the surface of the soft soil layer 1, and connect it to the water collection pipe 8 through the joint 10;

[0051] Step 4: construct the sand cushion layer 2, and lay the second geotextile 6 on the surface of the sand cushion layer 2;

[0052] Step 5: construct the loading layer 3. After the loading is completed, install the fully automatic submersible pump 11. When the water level in the assembled water collection manhole 4 is too high, the fully automatic submersible pump 11 will automatically start and discharge the water to the outside of the assembled water collection manhole 4 through the water pipe 12.

[0053] Although the implementation scheme of the utility model has been disclosed as above, it is not limited to the applications listed in the specification and implementation modes. It can be fully applied to various fields suitable for the utility model. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A drainage system suitable for preloading and drainage consolidation of high mud content sand cushion layer, characterized in that: It comprises a sand cushion layer laid on the upper part of the soft soil layer, a heap layer laid on the upper part of the sand cushion layer, and an assembled water collection manhole with the bottom located in the soft soil layer, wherein the top of the assembled water collection manhole extends upward to above the heap layer, a first geotextile is laid between the sand cushion layer and the soft soil layer, and a second geotextile is laid between the sand cushion layer and the heap layer; A plurality of vertical drainage boards are inserted inside the soft soil layer and the sand cushion layer, a water collecting pipe connected to the assembled water collecting manhole is horizontally arranged in the soft soil layer, and a plurality of drainage pipes are longitudinally arranged in the sand cushion layer, and the drainage pipes are connected to the water collecting pipes through joints; The wall of the drainage pipe is in a spiral corrugated structure with the same pitch and waveform and a continuous direction, and the cross section of the spiral corrugated structure is circular.

2. The drainage system suitable for preloading and drainage consolidation of high mud content sand cushion layer as claimed in claim 1, characterized in that: The assembled water collection manhole comprises a concrete bottom plate and a circular prefabricated part, and a plurality of the circular prefabricated parts are vertically stacked on the concrete bottom plate; A fully automatic submersible pump is installed inside the assembled water collection manhole. The fully automatic submersible pump includes a water delivery pipe, and the water delivery pipe extends upward to the outside of the assembled water collection manhole.

3. The drainage system suitable for preloading and drainage consolidation of high mud content sand cushion layer as claimed in claim 1, characterized in that: The drainage pipe is wrapped with a layer of non-woven geotextile.

4. The drainage system suitable for preloading and drainage consolidation of high mud content sand cushion layer as claimed in claim 1, characterized in that: Both ends of the water collecting pipe are 10 cm lower than the surface of the soft soil layer and are arranged toward the assembled water collecting manhole with a slope of 0.5%.

5. The drainage system suitable for preloading and drainage consolidation of high mud content sand cushion layer as claimed in claim 1, characterized in that: The drainage pipe is set 10 cm above the surface of the soft soil layer, and the horizontal drainage pipes are arranged at a spacing of 12 m.

6. The drainage system suitable for preloading and drainage consolidation of high mud content sand cushion layer as claimed in claim 1, characterized in that: The vertical drainage board is a plastic drainage board, and the vertical drainage board is set according to 1.0m*1.0m and arranged in a square.

7. The drainage system suitable for preloading and drainage consolidation of high mud content sand cushion layer as claimed in claim 1, characterized in that: The joint is a three-way joint or a 90° elbow joint.

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