Foundation reinforcing and deviation rectifying method

[0035] The specific embodiments of the present invention will be described in further detail below in conjunction with the drawings and embodiments. The following examples are used to illustrate the present invention, but not to limit the scope of the present invention.

[0036] In the description of the present invention, it should be noted that the terms “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, The orientation or positional relationship indicated by "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the device or The element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0037] In the description of the present invention, it should be understood that the terms "connected", "connected", "fixed" and other terms used in the present invention should be understood in a broad sense. For example, it may be a fixed connection or a detachable connection, or Integrated; can be mechanical connection or welding connection; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined . For those of ordinary skill in the art, the specific meaning of the above-mentioned terms in the present invention can be understood according to specific circumstances.

[0038] Such as Figure 1 to Figure 6 As shown, a preferred embodiment of the present invention provides a foundation reinforcement and correction method, including the following steps: a first pile hole 1 is opened on the ground of the foundation to be constructed and extended to the deep soil, and the first pile hole 1 is surrounded Anchor rod reinforcement 2 is implanted; the foundation is used as the reaction platform 10, and the steel pipe pile 3 is pressed into the first pile hole 1 through the anchor static pressure construction method; the configured grouting solution is passed through the steel The grouting port 4 of the pipe pile 3 is squeezed and grouted, and the deep soil is compacted and reinforced by repeated grouting of "grouting-cleaning-grouting"; after the grouting is completed, pass the anchor rod The steel bar 2 fixes the pressure component, and uses the pressure component to temporarily lock the steel pipe pile 3; a plurality of second pile holes are opened on the ground of the foundation to be constructed or the ground between the two foundations and extend to the shallow soil The grouting steel pipe 5 is inserted into each of the second pile holes, and the grouting liquid is squeezed and grouted through the grouting steel pipe 5, and the shallow soil is locally oriented and reinforced in the same repeated grouting method. , So that the settled soil layer below the foundation is raised and corrected; during the grouting process of the grouting steel pipe 5, the pressure change value of the steel pipe pile 3 is obtained, and the pressure change of the steel pipe pile 3 is judged If the value exceeds the preset value, if so, the compression component is used to compensate and pressurize the steel pipe pile 3 to ensure the bearing capacity of the steel pipe pile 3; after the reinforcement and correction are completed, the compression component Remove, pour concrete into the steel pipe pile 3, and fix the steel pipe pile 3, the grouting steel pipe 5 and the foundation as a whole by pouring a concrete foundation beam 15.

[0039] Based on the above-mentioned technical features of the method for foundation reinforcement and correction, the steel pipe pile 3 is pressed into the first pile hole 1 by the anchor static pressure construction method, and the grouting liquid is passed through the steel pipe pile 3 to the deep soil After the grouting is completed, the steel pipe pile 3 is locked by the pressurized component, and then the shallow soil body is oriented and reinforced by the grouting steel pipe 5 in the second pile hole. The pressure value change of the steel pipe pile 3 is monitored. If the pressure value of the steel pipe pile 3 is lost, the pressure component is used to compensate and press the steel pipe pile 3 to ensure a single steel pipe pile 3. The bearing capacity of 3, through the hole bottom mixing, quick-setting compaction directional reinforcement technology, from the deep and shallow parts, respectively, compact and strengthen the settlement soil under the foundation, repeated multiple grouting and multiple simultaneous grouting to achieve the settlement of the soil Slowly directional uplift, strengthen and correct the uneven settlement that has occurred between the foundations, which can effectively reduce or eliminate the uneven settlement that has occurred and the inclination of the overall building. At the same time, the steel pipe piles are replaced by the newly cast foundation beam 15 3. The grouting steel pipe 5 is connected with the original foundation to strengthen the rigidity of the foundation and realize the integration of reinforcement and correction.

[0040] Before construction, the steel pipe pile 3 needs to be calculated and prefabricated, such as figure 2 As shown, first, according to the upper load of the building and the distance between the piles, the characteristic value of the bearing capacity of the single pile is calculated and determined, and then the length of the steel pipe pile 3 is estimated according to the geological conditions of the site. Generally, it can pass through the clay layer and the fully weathered layer, the strong weathered layer can enter 1-2m, and the medium and slightly weathered rock layer cannot enter. According to the estimated pile length and characteristic value of single pile bearing capacity, steel pipe piles 3 with a diameter of 127, 159 or 250 mm and a wall thickness of 8-14 mm are selected. If the calculated pile diameter is too large, the spacing between the steel pipe piles 3 can be appropriately compressed to reduce the characteristic value of the single pile's bearing capacity, thereby reducing the pile diameter and avoiding the difficulty of pile pressing.

[0041] According to the estimated pile length and pile diameter, make the steel pipe pile 3 first. The length of each section of steel pipe is not less than 2.0m, which can be determined according to the actual situation on site. The joint of each section of steel pipe adopts 45 degree groove welding, and then 4 Bar diameter 14-16mm, length 200mm steel bar or 3 pieces of 200×40×10mm (length×width×thickness) steel sheets tied and welded, and the outlet 4 is arranged within a range of 1-2m above the bottom of the pile to achieve injection The slurry is rapidly solidified in the deep position of the settled soil layer, and plays a role of uplifting and directional for the settled soil layer. The bottom of the steel pipe pile 3 is provided with a diamond-shaped pile tip 6 to facilitate pile pressing construction.

[0042] In this embodiment, the step of performing squeeze grouting with the configured grouting liquid through the grouting port 4 of the steel pipe pile 3 further includes: finishing before the pile pressing, and the steel pipe The first grouting pipe 7 (diameter 45-50mm, wall thickness 3-4mm) is welded in the pile 3, and the second grouting pipe 8 is inserted into the first grouting pipe 7 and extended to the grouting outlet 4, The grouting liquid passes through the second grouting pipe 8 to directly squeeze and reinforce the bottom of the steel pipe pile 3.

[0043] Wherein, a grouting plug 9 is provided between the outer wall of the first grouting pipe 7 and the inner wall of the steel pipe pile 3, and a steel plate is welded in the pipe at a distance of 2m from the pile bottom as a grouting plug 9 for isolation. In dense grouting, the grouting plug 9 prevents the grouting liquid from flowing upward, and the grouting plug 9 is welded by steel plates.

[0044] In this embodiment, the first pile hole 1 is opened on the ground of the foundation to be constructed and extends to the deep soil, and the step of implanting the anchor rod reinforcement 2 around the first pile hole 1 is specifically: The first pile hole 1 is drilled on the foundation ground, the diameter of the first pile hole 1 is slightly larger than the diameter of the steel pipe pile 3, and the first pile hole 1 is planted around For the pile cap beam reinforcement and the threaded anchor rod reinforcement 2, if the foundation ground is not a horizontal surface, such as an inclined surface or a concave-convex surface, a horizontal construction platform should be constructed as the reaction platform 10 first.

[0045] In this embodiment, in the step of pressing the steel pipe pile 3 into the first pile hole 1 through the anchor rod static pressure construction method, it further includes: pressing the steel pipe pile 3 and vertical In order to maintain the vertical pressure of the steel pipe pile 3, the pile pressing pressure acting on the steel pipe pile 3 does not exceed the maximum pile pressing pressure. The pile pressing process must be continuous and keep the pile section vertical. The pile pressing force shall not exceed the designed maximum pile pressing force. The pressure, the verticality of the pile, the intermittent time of pile connection, the connection quality and the pressing depth of the pile shall be checked in time, and the final pile shall be checked. It is controlled in accordance with the principle of combining the pressure of the pile and the amount of steady-state settlement.

[0046] In this embodiment, combining figure 1 As shown, in the step of fixing the pressurizing assembly by the anchor bar 2 and temporarily locking the steel pipe pile 3 by the pressurizing assembly, specifically: pressing the first press of the pressurizing assembly The pile block 11 is fixed on the ground of the foundation by the anchor rod reinforcement 2, and the second pressure pile block 12 of the compression assembly is fixed above the first pressure pile block 11 by the anchor rod reinforcement 2 , A jack 13 is arranged between the first pile pressing block 11 and the second pile pressing block 12, and the jack 13 is used to prestress the steel pipe pile 3. When the pressure loss is too large, the jack 13 can be used to repress the steel pipe pile 3 to ensure the single pile bearing capacity of the steel pipe pile 3.

[0047] Wherein, the anchor rod reinforcement 2 is a threaded reinforcement anchor rod, and the anchor rod reinforcement 2 is provided with a nut for adjusting the position of the first pile pressing block 11 and the second pile pressing block 12. The first pile pressing block 11 is fixed, and the second pile pressing block 12 is fixed by the anchor rod reinforcement 2 and the nut to realize a progressive bolt pile sealing structure, convenient and simple to operate, and temporarily locked The steel pipe pile 3 can adjust the pressure value of the steel pipe pile 3 to ensure that the steel pipe pile 3 has a proper preload during the pile sealing process, realize the coordinated work of the pile-soil foundation, and effectively eliminate the later settlement.

[0048] Further, there are multiple anchor bars 2 in number, and each anchor bar 2 is arranged around the steel pipe pile 3 in a rectangular array, so that the pressure acting on the steel pipe pile 3 is more uniform.

[0049] Wherein, the steel pipe pile 3 is repeatedly grouted, after each grouting, the remaining grout in the pipe is rinsed with clean water, and then grouting is performed to form the repeated grouting of "grouting-cleaning-grouting". The pulping method achieves the effect of slow lifting.

[0050] In this embodiment, the grouting solution is configured by cement slurry, water glass and liquid water, the water cement ratio of the cement slurry is 1:0.5 to 1.0, and the cement slurry, the water glass and the The volume ratio of liquid water is (1.0~1.5):1:(2~3) in order to realize the process of fast-setting compaction and directional reinforcement, and carry out slow lifting correction.

[0051] In this embodiment, combining Figure 4 with Figure 5 As shown, the opening direction of the second pile hole is vertical or oblique, and each second pile hole faces the steel pipe pile 3. Arrange a grid-like capillary grouting steel pipe 5 with a length of 5m~8m in the settlement soil layer, the pipe diameter Combination of length and short length, local compaction and reinforcement of the soil under the foundation, simultaneous grouting in multiple locations, compaction and grouting of the ground above the bottom of the pile, and multiple pipe grouting to reinforce the main soil layer around the steel pipe pile 3 Directional uplifting further reduces differential settlement.

[0052] In this embodiment, the grouting liquid is squeezed and grouted through the grouting steel pipe 5, and the shallow soil is partially oriented and reinforced in the same repeated grouting method, so that the settlement soil below the foundation The steps of layer uplifting and deviation correction are specifically: dividing the configured grouting liquid into multiple groups, and passing each group of the grouting liquid through the grouting steel pipe 5 for repeated "grouting-cleaning-grouting" Squeeze grouting to carry out multiple directional reinforcements on multiple local positions of the settlement soil layer, so that the settlement soil layer gradually rises upwards and tends to a stable state. Among them, different grouting steel pipes 5 adopt different grouting amounts. The grouting liquid is used to perform differentiated reinforcement for each local position, and then through the gradual recompression of the steel pipe pile 3 to achieve reinforcement lifting and correction simultaneously, to achieve the purpose of correcting the uneven settlement of the settled soil layer .

[0053] Wherein, the grouting steel pipe 5 is a single-bolt steel pipe, and the overall grouting sequence can be from outside to inside. The grouting steel pipe 5 and the grouting liquid are grouped according to the actual situation of the site and the distribution form of the foundation layer. The group of grouting steel pipes 5 can be grouted with multiple groups of the grouting liquids, through the method of "repeating a small amount and many times", until the uneven settlement of the foundation soil layer stabilizes, or after it is raised to the design requirements and stabilized , Grouting can be stopped. Different grouting steel pipes 5 are used to use different grouting amounts of the grouting liquid to differentiate uplifting each local location, which means that different locations have different lifting amplitudes to overcome the uneven settlement of the settled soil layer. To achieve the purpose of rectifying deviation, real-time monitoring of buildings and foundation pits should be strengthened during grouting to avoid disturbing buildings and supporting equipment, and timely adjust grouting pressure and grouting volume to achieve information construction.

[0054] Wherein, the grouting steel pipe 5 can be repeatedly grouted. After each grouting, rinse the remaining grout in the pipe with clean water to keep the grouting steel pipe 5 clean and seal it with a lid. When grouting next time, insert a small diameter into the pipe The inner grouting pipe can start double-fluid grouting repeatedly to avoid multiple holes, which is the repeated grouting method of "grouting-cleaning-grouting". The grouting pressure of the grouting steel pipe 55 is 0.8-2.0MPa, and the depth of the grouting port of the grouting steel pipe 55 is 5-8m, which can be deepened appropriately according to the condition of the base soil layer. The grouting material also adopts double liquid grout , The solidification time of the grouting liquid is not more than 10s, the grouting speed is not more than 70 liters/min, and the ratio is finally determined through field tests.

[0055] In this embodiment, in the step of fixing the steel pipe pile 3, the grouting steel pipe 5 and the foundation as a whole by pouring a concrete foundation beam 15, specifically: implanting a concrete foundation beam on the ground of the foundation The fixed steel bars 14 crisscross each other are poured into a foundation beam 15 through concrete to fix the steel pipe pile 3, the grouting steel pipe 5 and the foundation as a whole. The type and quantity of the fixed steel bars 14 need to meet the cross-sectional shear check calculation, and the outer wall of the steel pipe pile 3 and the original foundation soil layer should be filled with ultra-fine cement slurry to ensure that the steel pipe pile 3 is in line with the original Effective connection and fixation of the foundation soil layer.

[0056] The following uses actual application examples as supplementary explanations. The foundation pit support project (Phase I) of the Medical Complex Building of Nanfang Hospital is located in the Nanfang Hospital of Southern Medical University, Guangzhou Avenue North, Guangzhou City. There are three basements under it, and the building is equivalent to the height of the urban construction of Guangzhou. 35.00m, the perimeter of the foundation pit is about 400m, and the excavation depth of the foundation pit is about 12.30~15.40m. The excavation of the foundation pit reveals the fill, alluvial clay layer, sand layer, plastic and hard residual clay layer, etc. in turn. The bottom of the foundation pit is mainly located in the clay layer, partially located in the fully weathered rock layer. The surrounding environment of the foundation pit is complex. The north side is adjacent to the surgical building (13 floors, independent foundation, one basement, and the foundation is about 5.2m deep), and it is about 6.0m from the edge of the basement of the medical complex building; the east side is a dormitory building with 2 to 19 floors. It is about 18.3m from the basement side. The basement on the south side of the foundation pit is 5.0m away from the road. The independent foundation of the 5-story medical technology building on the northwest side of the foundation pit is about 8.3m away from the edge of the basement. There are water supply and drainage pipelines and power supply lines under the roads on the east and south sides. Precision instruments such as DSG and r-knife are installed in the basement of the North Surgery Building, and precision instruments such as MRI imagers are installed in the Northwest Medical Technology Building, which are sensitive to distortion, vibration, and noise, and need special protection.

[0057] During the construction of the foundation pit supporting structure and the main structure of the plain concrete piles, uneven settlement occurred on the north and west sides of the foundation pit. The maximum settlement in the southeast corner of the surgical building reached 38.5mm, and the inclination rate of the southeast corner reached 4.25‰. Exceed the design control value. In order to avoid the danger of the continuous development of settlement, the construction site of the support structure was suspended, and the foundation reinforcement and correction structure and reinforcement correction method in this embodiment were used to carry out the separate (strip) foundation and the soil under the foundation on the north and west sides of the foundation pit. Rescue and reinforcement, to achieve directional uplift and reinforcement correction of areas with large settlements, and reduce uneven settlement of the foundation soil. After reinforcement and correction, the uneven settlement of the surgical building was effectively controlled. After the southeast corner (the maximum settlement point) was properly raised, the settlement was stabilized at about 15mm, and the corner inclination rate was restored to about 1.5‰, ensuring that the main structure of the surgical building continued It is safe to use and has good social and economic benefits.

[0058] In summary, the embodiment of the present invention provides a foundation reinforcement and correction method with the following advantages: (1) Using anchor rod static pressure to apply prestress on the top of the steel pipe pile 3, effectively traction of the foundation soil layer, reducing repetition during construction The uneven settlement and uplifting realizes the synergy of the foundation soil layer, the steel pipe pile 3 and the foundation to form a traction steel pipe pile 3 to give full play to the bearing capacity of the soil under the foundation and try not to change the stress state of the original structure; 2) A first grouting pipe 77 is set on the steel pipe pile 3, and squeezing grouting is carried out through the second grouting pipe 8. The triple pipe grouting strengthens the soil around the steel pipe pile 3, and directionally lifts the pile soil from the deep part. Community, reduce the uneven settlement that has occurred (differential settlement); (3) Arrange the grid-like grouting steel pipe 5, local directional extrusion grouting, combination of length and short length, compaction and reinforcement of the soil under the foundation to achieve directional realization The shallow layer is mainly stressed by the directional uplift to further reduce the differential settlement; (4) The directional grouting uplift is used to rectify the deviation. The hole bottom mixing and quick-setting compaction directional reinforcement technology are used to compact and strengthen the underlying soil from the deep and shallow parts. Body, repeated grouting and multi-point grouting at the same time, to achieve reinforcement and correction in one; (5) Convenient construction, adjustable pre-stressed anchor seal. It adopts the repeated progressive screw-type pile sealing structure, and observes the load loss of the anchor static pressure pile through the pressure gauge. If there is any loss, the pressure can be restored to ensure the bearing capacity of the single pile and effectively reduce the settlement after stopping the grouting; (6) The construction period is short, which can save about 20-50% of the construction cost and about 30-60% of the construction period compared with the conventional method.

[0059] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principles of the present invention, several improvements and substitutions can be made. These improvements and substitutions It should also be regarded as the protection scope of the present invention.