Foundation pit construction method based on vibration reduction isolation piles

Abstract

The foundation pit construction method based on the vibration reduction isolation piles comprises the following steps that a drilling machine is adopted to drill holes in the boundary between a target construction area and an adjacent building, each drill hole sequentially penetrates through a soil stratum and a rock stratum, and a plurality of first pile holes are formed; the part, making contact with the rock stratum, of each first pile hole is filled with sand to form a sand pile, the part, making contact with the soil stratum, of each first pile hole is inserted into a steel pipe, the position between the steel pipe and the soil stratum is filled with cement paste to form an annular steel pipe pile, and the sand piles and the steel pipe piles are combined into a vibration reduction isolation pile foundation; and foundation pit construction is conducted in the target construction area. The method has the beneficial effects that the vibration reduction and isolation pile foundation compounded with the sand piles and the steel pipe piles is arranged at the boundary between the target construction area and the adjacent building in advance, and vibration caused by excavation of the foundation pit soil layer and the rock layer and disturbance to the nearby soil layer are reduced through the vibration reduction and isolation pile foundation.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit support, and in particular to a foundation pit construction method based on vibration-damping isolation piles. Background Art

[0002] In order to create conditions for underground structure construction in urban construction, the step of excavating foundation pits is essential. In fact, when excavating foundation pits, there are often existing buildings nearby, and the soil layer is loose and easy to deform. Excavation of foundation pits in the soil layer is easy to cause disturbance of the soil layer, thereby causing deformation of the soil layer and affecting the surrounding environment. The rock layer is relatively solid and not easy to deform, but the construction of bored piles and foundation pit excavation in the rock layer is easy to cause vibration, which will also affect the surrounding environment. In particular, buildings that have been built for a long time in the environment around the foundation pit are more sensitive to ground deformation and settlement. Moreover, the vibration caused by bored pile construction and rock excavation construction will also disturb people in the building and affect their rest. Summary of the invention

[0003] In view of the above problems, the present invention proposes a foundation pit construction method based on vibration-damping isolation piles, which is used for soil-rock composite strata. Under the premise of meeting the requirements of cover plate excavation and support, it reduces the vibration caused by excavation of foundation pit soil and rock strata, as well as the disturbance to nearby soil strata.

[0004] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0005] A foundation pit construction method based on vibration-damping isolation piles comprises the following steps:

[0006] A drilling machine is used to drill holes at the boundary between the target construction area and the adjacent buildings, and each borehole penetrates the soil stratum and the rock stratum in sequence to form a number of first pile holes;

[0007] The part of each first pile hole in contact with the rock formation is filled with sand to form a sand pile, and the part of the first pile hole in contact with the soil formation is inserted into a steel pipe, and cement slurry is filled between the steel pipe and the soil formation to form a ring-shaped steel pipe pile, and the sand pile and the steel pipe pile are combined into a vibration reduction isolation pile foundation;

[0008] Carry out foundation pit construction in the target construction area.

[0009] In some embodiments, the process of foundation pit construction includes:

[0010] A drilling rig is used to drill holes around the target construction area, and each hole penetrates the soil stratum and the rock stratum in turn to form a number of second pile holes;

[0011] Concrete is poured into the second pile hole to form a bored pile, and steel sheet piles are arranged from the outside of the bored pile, and steel supports are arranged between the steel sheet piles;

[0012] Excavating the cover pit, and then pouring the cover in the space of the cover pit;

[0013] Cover the top of the cover with soil and restore the ground surface to recover the steel sheet piles and steel supports;

[0014] The soil and rock strata are excavated under the cover slab to eventually form a foundation pit.

[0015] In some embodiments, the distance between the sand pile and the soil formation is greater than or equal to 1 meter.

[0016] The beneficial effect of the present invention is that a vibration-damping isolation pile foundation composed of a composite of sand piles and steel pipe piles is set in advance at the boundary between the target construction area and the adjacent buildings, and the vibration caused by the excavation of the foundation pit soil and rock layers, as well as the disturbance to the nearby soil layers, is reduced by the vibration-damping isolation pile foundation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A top view of a first pile hole disclosed in an embodiment of the present invention;

[0018] Figure 2 A cross-sectional view of a first pile hole disclosed in an embodiment of the present invention;

[0019] Figure 3a A cross-sectional view of a vibration-damping isolation pile foundation disclosed in an embodiment of the present invention;

[0020] Figure 3b for Figure 3a A cross-sectional view at section AA;

[0021] Figure 3c for Figure 3a A cross-sectional view at section BB;

[0022] Figure 4 A cross-sectional view of a second pile hole disclosed in an embodiment of the present invention;

[0023] Figure 5 It is a schematic diagram of the structure of the cast-in-place pile disclosed in the embodiment of the present invention;

[0024] Figure 6 It is a schematic diagram of the structure of a steel sheet pile disclosed in an embodiment of the present invention;

[0025] Figure 7 A schematic diagram of the structure of a cover plate disclosed in an embodiment of the present invention;

[0026] Figure 8 A schematic diagram of the excavation structure of a foundation pit disclosed in an embodiment of the present invention;

[0027] Among them: 1-target construction area, 2-adjacent buildings, 3-soil stratum, 4-rock stratum, 5-first pile hole, 51-steel pipe pile, 501-steel pipe, 52-sand pile, 6-second pile hole, 7-steel sheet pile, 8-steel support, 9-cover plate, 100-easily disturbed soil. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer and more specific, the content of the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, rather than all the contents.

[0029] This embodiment proposes a foundation pit construction method based on vibration-damping isolation piles, comprising the following steps:

[0030] Step 1, such as Figure 1 and 2 As shown, a drilling machine is used to drill holes at the boundary between the target construction area 1 and the adjacent building 2, and each drill hole penetrates the soil stratum 3 and the rock stratum 4 in sequence to form a plurality of first pile holes 5.

[0031] Step 2, such as Figure 3a , 3b As shown in Figure 3c, the part of each first pile hole 5 that contacts the rock formation 4 is filled with sand to form a sand pile 52. There are pores in the sand pile 52, which can absorb part of the vibration. The part of the first pile hole 5 that contacts the soil formation 3 is inserted into a steel pipe 501, and cement slurry is filled between the steel pipe 501 and the soil formation 3 to form a ring-shaped steel pipe pile 51. The steel pipe pile 51 has a large rigidity and can play a good isolation role to reduce the disturbance and deformation of the soil. The sand pile 52 and the steel pipe pile 51 are combined into a vibration-damping isolation pile foundation. Optionally, the distance between the sand pile 52 and the soil formation 3 is greater than or equal to 1 meter, serving as an embedded foundation for the steel pipe pile 51.

[0032] Step 3: Conduct foundation pit construction in the target construction area 1.

[0033] The process of foundation pit construction includes:

[0034] Step 301, such as Figure 1 and 4 As shown, a drilling rig is used to drill holes around the target construction area 1, and each drill hole sequentially penetrates the soil stratum 3 and the rock stratum 4 to form a plurality of second pile holes 6. When the second pile holes 6 are constructed, when the rotary drill excavates the rock stratum 4, a large vibration will be generated, and when the vibration is transmitted to the sand pile 52, the loose structure of the sand pile will absorb part of the vibration, thereby preventing a large amount of vibration from being transmitted to the building, and reducing the impact of the vibration on the adjacent building 2 and personnel.

[0035] Step 302, such as Figure 5 and Figure 6 As shown, concrete is poured into the second pile hole 6 to form a bored pile, and steel sheet piles 7 are arranged from the outside of the bored pile, and steel supports 8 are arranged between the steel sheet piles 7.

[0036] Step 303, Figure 7 As shown, under the support of steel sheet piles 7, steel pipe piles 51 and steel supports 8, the cover plate pit is excavated, and then the cover plate 9 is cast in the space of the cover plate pit. Optionally, the cast-in-place piles (i.e., cement slurry poured in the second pile hole) can be reduced with the excavation of the cover plate pit.

[0037] Step 304, Figure 8 As shown, the oblique line in the figure is the vibration propagation direction. Cover the top of the cover plate 9 with soil, restore the ground, and recover the steel sheet piles 7 and steel supports 8;

[0038] Step 305, excavating the soil stratum 3 and the rock stratum 4 under the cover plate 9, and finally forming a foundation pit.

[0039] In step 305, the soil layer 3 under the cover plate 9 is first excavated. Since the soil layer 3 is loose, the excavation will cause deformation of the cast-in-place pile (i.e., the cement slurry poured in the second pile hole), and the deformation of the cast-in-place pile will cause the following problems: Figure 8 The deformation of the easily disturbed soil 100 shown in the figure will cause the adjacent building 2 to tilt toward the foundation pit, which may easily cause the building to crack. Under the action of the steel pipe piles 51 in this solution, the soil disturbance at the top of the foundation pit will be weakened at the position of the steel pipe piles 51, reducing the impact on the building.

[0040] For the excavation of the rock stratum 4 under the cover plate 9, since the rock stratum 4 is relatively hard, it needs to be chiseled out forcefully. This process will cause vibration of a large amplitude, which will also be transmitted to the adjacent buildings 2, affecting the adjacent buildings 2 and personnel. At this time, the sand piles 52 play a role in absorbing the vibration and reducing the impact of construction.

[0041] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made based on the essence of the content of the present invention should be included in the protection scope of the present invention.

Claims

1. A foundation pit construction method based on vibration-damping isolation piles, characterized in that: The following steps are involved: A drilling machine is used to drill holes at the boundary between the target construction area and the adjacent buildings, and each borehole penetrates the soil stratum and the rock stratum in sequence to form a number of first pile holes; The part of each first pile hole in contact with the rock formation is filled with sand to form a sand pile, and the part of the first pile hole in contact with the soil formation is inserted into a steel pipe, and cement slurry is filled between the steel pipe and the soil formation to form a ring-shaped steel pipe pile, and the sand pile and the steel pipe pile are combined into a vibration reduction isolation pile foundation; Carry out foundation pit construction in the target construction area.

2. The foundation pit construction method based on vibration-damping isolation piles according to claim 1, characterized in that: The process of foundation pit construction includes: A drilling rig is used to drill holes around the target construction area, and each borehole penetrates the soil stratum and the rock stratum in turn to form a number of second pile holes; Concrete is poured into the second pile hole to form a bored pile, and steel sheet piles are arranged from the outside of the bored pile, and steel supports are arranged between the steel sheet piles; Excavating the cover pit, and then pouring the cover in the space of the cover pit; Cover the top of the cover with soil and restore the ground surface to recover the steel sheet piles and steel supports; The soil and rock strata are excavated under the cover slab to eventually form a foundation pit.

3. The foundation pit construction method based on vibration-damping isolation piles according to claim 1 is characterized in that: The distance between the sand pile and the soil stratum is greater than or equal to 1 meter.

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