Pier foundation hole digging method for mountainous complex rock-soil layer

Abstract

The invention relates to the technical field of pier foundation hole digging, in particular to a pier foundation hole digging method for a mountainous complex rock-soil layer. The method specifically comprises the following steps that the design position of a pier foundation is determined according to a design drawing, and an excavation range is marked on the ground; if the ground in the excavation range is a soil layer, hole digging is conducted on the soil layer in the excavation range manually till the designed depth is reached, and a pier foundation hole is formed; if the ground of the excavation range is a rock stratum, a drilling tool is provided, drilling is conducted on the rock stratum along the edge of the excavation range to form an annular temporary hole, then the rock stratum in the middle of the excavation range is crushed and taken out, and the steps are repeated till the designed depth is reached to form a pier foundation hole. The method has the beneficial effects that holes are dug in a soil layer and a rock layer by adopting different processes, the soil layer is dug manually, the rock layer at the edge of the digging range is firstly drilled by utilizing a drilling tool to form an annular adjacent hole, then the rock layer in the middle is crushed, the crushed rock layer is taken out, and then a pier foundation hole is formed.

Description

Technical Field

[0001] This invention relates to the field of pier foundation excavation technology, and specifically to a method for pier foundation excavation in complex rock and soil layers in mountainous areas. Background Technology

[0002] With the rapid development of the construction industry, especially the rise of the cold chain logistics industry in mountainous areas, the demand for cold chain infrastructure construction in these regions is increasing. However, the complex geological conditions, particularly rock geology, in mountainous areas present significant challenges to construction. Traditional foundation types, such as natural independent foundations, raft foundations, and pier foundations, often struggle to meet the requirements for high load-bearing capacity and resistance to lateral slippage in rocky geological conditions. Therefore, a new type of foundation is needed for buildings in mountainous areas that can provide both high load-bearing capacity and effective resistance to lateral slippage.

[0003] Currently, the closest existing technical solution to this invention is construction using manual excavation (enlargement) of holes. This method can adapt to rock geological conditions to some extent, increasing the bearing area and stability of the foundation through excavation and enlargement. However, although this method improves the bearing capacity of the foundation to a certain extent, it still has certain limitations and challenges in rock geological conditions, such as high construction difficulty, high cost, and long construction period. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for excavating pier foundations in complex rock and soil layers in mountainous areas, which solves the problems of high difficulty, high cost and long construction period in the excavation of rock geology by existing excavation methods.

[0005] The technical solution to achieve the above objectives is:

[0006] This invention provides a method for excavating boreholes for pier foundations in mountainous areas with complex rock and soil layers, specifically including the following steps:

[0007] Based on the design drawings, determine the design location of the pier foundation and mark the excavation area on the ground;

[0008] If the ground surface within the excavation area is soil, then manual excavation will be carried out on the soil within the excavation area until the design depth is reached to form the foundation hole for the pier.

[0009] If the ground surface of the excavation area is rock, provide drilling tools and use the drilling tools to drill along the edge of the excavation area into the rock layer to form a ring-shaped borehole. Then break up and remove the rock layer in the middle of the excavation area. Repeat the above steps until the design depth is reached to form the pier foundation hole.

[0010] Furthermore, before drilling to form an annular borehole, several circular core sampling points are closely arranged along the inner edge of the excavation area, so that adjacent core sampling points are tangent to each other and the core sampling points are tangent to the inner side of the excavation area.

[0011] Then, drilling tools are used to drill the rock strata at the core sampling point to form a ring-shaped borehole.

[0012] Furthermore, when breaking the rock strata in the middle of the excavation area, six cutting lines are marked on the rock strata, so that the cutting lines are distributed along the radius of the rock strata, dividing the rock strata into six equal parts;

[0013] Then, cut along three of the cutting lines in sequence to divide the rock layer into three equal parts;

[0014] Finally, cut along the remaining three cutting lines in sequence, dividing each cut rock layer into two equal parts.

[0015] Furthermore, when dividing the rock strata into three equal parts, the drilling tool is used to drill along the radius of the rock strata;

[0016] When dividing each cut rock layer into two equal parts, a hand drill is provided. The hand drill is used to drill holes at intervals along the corresponding cutting lines. Then, steel wedges are provided and gradually driven into the drill holes to cause adjacent rock layers to crack along the corresponding cutting lines and to create horizontal cracks at the bottom of the rock layers.

[0017] Furthermore, the drilling tool is a water-cooled drill.

[0018] Furthermore, after the rock strata are excavated and the foundation hole is formed, the inner wall of the foundation hole is modified to form a smooth and continuous arc surface.

[0019] Furthermore, before excavating the soil layer, the soil layer is divided into multiple upper and lower sections, and during excavation, the soil layers are excavated sequentially from top to bottom.

[0020] Furthermore, before excavating the soil layer, a well ring lock is installed on the soil layer along the edge of the excavation area; during excavation, the soil layer inside the well ring lock is excavated; after the foundation hole of the pier is completed, the well ring lock is removed.

[0021] Furthermore, after excavation of each section of soil, steel bars and formwork are provided. The steel bars are placed on the wall of the excavated hole and covered with formwork. Then, concrete is poured into the formwork to form a retaining wall. After the retaining wall reaches the design strength, the formwork is removed and the next section of soil is excavated.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] Different excavation techniques were used for soil and rock strata. Soil strata were excavated manually, while rock strata were first drilled at the edge of the excavation area to create a ring-shaped pre-drilling hole. Then, the central rock strata were broken up and removed to form the foundation hole. By using drilling tools to create a ring-shaped pre-drilling hole, the rock strata in the center of the excavation area were separated from those outside the excavation area, and the central rock strata were broken up, avoiding direct manual excavation and improving excavation efficiency.

[0024] A water-cooled drill is used to drill through the rock strata to create a ring-shaped borehole. This borehole has sufficient width to facilitate the breaking of the central rock strata. The central rock strata are then broken into six equal parts, allowing for the individual extraction of each broken section. Attached Figure Description

[0025] Figure 1 This is a construction flowchart of the method for excavating boreholes for pier foundations in complex rock and soil layers in mountainous areas, as described in this invention.

[0026] Figure 2 This is a flowchart illustrating the rock stratum excavation process of the present invention for the method of excavating boreholes for pier foundations in complex mountainous soil and rock layers. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] See Figure 1 This invention provides a method for excavating foundation holes for piers in complex rock and soil layers in mountainous areas, solving the problems of high difficulty, high cost, and long construction period associated with existing excavation methods when excavating rock geology. Different excavation processes are used for soil and rock layers. Soil layers are excavated manually, while rock layers are first drilled using drilling tools to form a ring-shaped pre-drilling hole at the edge of the excavation area. Then, the rock layer in the middle is broken up and removed to form the foundation hole. By using drilling tools to form a ring-shaped pre-drilling hole, the rock layer in the middle of the excavation area is separated from the rock layer outside the excavation area, and the rock layer in the middle is broken up, avoiding direct manual excavation of the rock layer and improving the efficiency of excavation.

[0029] A water-cooled drill is used to drill through the rock strata to create a ring-shaped borehole. This borehole has sufficient width to facilitate the breaking of the central rock strata. The central rock strata are then broken into six equal parts, allowing for the individual extraction of each broken section.

[0030] The following description, in conjunction with the accompanying drawings, illustrates a method for excavating boreholes for pier foundations in mountainous areas with complex rock and soil layers, in accordance with the present invention.

[0031] See Figure 1This document displays a construction flowchart of the present invention's method for excavating boreholes for pier foundations in complex mountainous soil and rock layers. (See also...) Figure 2 This document displays a flowchart of the rock stratum excavation process for the pier foundation excavation method of the present invention, applicable to complex rock and soil strata in mountainous terrain. The following section, in conjunction with... Figure 1 and Figure 2 This invention describes a method for excavating boreholes for pier foundations in complex rock and soil layers in mountainous areas.

[0032] like Figure 1 and Figure 2 As shown, the present invention describes a method for excavating holes for pier foundations in complex rock and soil layers in mountainous areas, specifically including the following steps:

[0033] Based on the design drawings, determine the design location of the pier foundation and mark the excavation area on the ground;

[0034] If the ground surface within the excavation area is soil, then manual excavation will be carried out on the soil within the excavation area until the design depth is reached to form the foundation hole for the pier.

[0035] If the ground surface of the excavation area is rock, provide drilling tools and use the drilling tools to drill along the edge of the excavation area into the rock layer to form a ring-shaped borehole. Then break up and remove the rock layer in the middle of the excavation area. Repeat the above steps until the design depth is reached to form the pier foundation hole.

[0036] In one specific embodiment, before drilling to form an annular borehole, several circular core sampling points are closely arranged along the inner edge of the excavation range, so that adjacent core sampling points are tangent to each other and the core sampling points are tangent to the inner side of the excavation range.

[0037] Then, drilling tools are used to drill the rock strata at the core sampling point to form a ring-shaped borehole.

[0038] Furthermore, when breaking the rock strata in the middle of the excavation area, six cutting lines are marked on the rock strata, so that the cutting lines are distributed along the radius of the rock strata, dividing the rock strata into six equal parts;

[0039] Then, cut along three of the cutting lines in sequence to divide the rock layer into three equal parts;

[0040] Finally, cut along the remaining three cutting lines in sequence, dividing each cut rock layer into two equal parts.

[0041] In one specific embodiment, when dividing the rock strata into three equal parts, the drilling tool is used to drill along the radius of the rock strata;

[0042] When dividing each cut rock layer into two equal parts, a hand drill is provided. The hand drill is used to drill holes at intervals along the corresponding cutting lines. Then, steel wedges are provided and gradually driven into the drill holes to cause adjacent rock layers to crack along the corresponding cutting lines and to create horizontal cracks at the bottom of the rock layers.

[0043] In one specific embodiment, the drilling tool is a water drill.

[0044] Specifically, the water-cooled drill bit has a diameter of 150mm and a length of 500mm. The diameter of the core sampling point is also 150mm, and the depth of each excavation of the rock strata is 500mm.

[0045] In one specific embodiment, after the rock strata are excavated and the foundation hole is formed, the inner wall of the foundation hole is modified to form a smooth and continuous arc surface.

[0046] Specifically, an electric hoist is provided and deployed above the excavation area of ​​the rock strata to lift the broken rock strata to the ground.

[0047] In one specific implementation, before excavating the soil layer, the soil layer is divided into multiple upper and lower sections, and during excavation, the soil layers are excavated sequentially from top to bottom.

[0048] In one specific embodiment, before excavating the soil layer, a well ring lock is installed on the soil layer along the edge of the excavation area; during excavation, the soil layer inside the well ring lock is excavated; after the foundation hole of the pier is completed, the well ring lock is removed.

[0049] Specifically, before excavating the soil layer, 20mm diameter steel bars are provided and driven vertically into the soil layer to test for quicksand and silt. When encountering sandy soil layers, after the excavation depth exceeds 5m, a blower is used to supply air into the hole. During excavation, the principle of excavating the center first, followed by the perimeter, is followed. Shovels and picks are used during excavation.

[0050] In one specific implementation, after each segment of soil is excavated, reinforcing bars and formwork are provided. The reinforcing bars are placed on the wall of the excavated hole and covered with formwork. Then, concrete is poured into the formwork to form a retaining wall. After the retaining wall reaches the design strength, the formwork is removed and the next segment of soil is excavated.

[0051] Specifically, the top of the formwork is trumpet-shaped, so that when pouring concrete, the concrete is poured into the formwork through the trumpet opening.

[0052] Specifically, the manhole ring interlock is constructed by laying reinforcing steel bars and pouring concrete. The concrete used is C25 concrete with a slump of 130mm and a wall thickness of 300mm. The top surface is 200mm higher than the construction base. During installation, some of the reinforcing steel bars in the manhole ring interlock are inserted into the ground and connected to the reinforcing steel bars of the retaining wall, thereby increasing the strength of the manhole ring interlock.

[0053] Specifically, before excavation, an electric winch and a bucket are provided. The bucket is attached to the lifting rope of the electric winch, which is then installed above the well ring lock. During excavation, the excavated soil is filled into the bucket, which is then lifted to the ground by the electric winch, thus removing the soil.

[0054] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A method for excavating boreholes for pier foundations in mountainous areas with complex rock and soil layers, characterized in that: Specifically, the steps include the following: Based on the design drawings, determine the design location of the pier foundation and mark the excavation area on the ground; If the ground surface within the excavation area is soil, then manual excavation will be carried out on the soil within the excavation area until the design depth is reached to form the foundation hole for the pier. If the ground surface of the excavation area is rock, provide drilling tools and use the drilling tools to drill along the edge of the excavation area into the rock layer to form a ring-shaped borehole. Then break up and remove the rock layer in the middle of the excavation area. Repeat the above steps until the design depth is reached to form the pier foundation hole.

2. The method for excavating boreholes for pier foundations in complex mountainous soil and rock layers according to claim 1, characterized in that: Before drilling to form a ring-shaped borehole, several circular core sampling points are closely arranged along the inner edge of the excavation area, so that adjacent core sampling points are tangent to each other and the core sampling points are tangent to the inner side of the excavation area. Then, drilling tools are used to drill the rock strata at the core sampling point to form a ring-shaped borehole.

3. The method for excavating boreholes for pier foundations in complex mountainous soil and rock layers according to claim 1, characterized in that: When breaking the rock strata in the middle of the excavation area, six cutting lines are marked on the rock strata, and the cutting lines are distributed along the radius of the rock strata to divide the rock strata into six equal parts; Then, cut along three of the cutting lines in sequence to divide the rock layer into three equal parts; Finally, cut along the remaining three cutting lines in sequence, dividing each cut rock layer into two equal parts.

4. The method for excavating boreholes for pier foundations in complex mountainous soil and rock layers according to claim 3, characterized in that: When dividing the rock strata into three equal parts, the drilling tool is used to drill along the radius of the rock strata; When dividing each cut rock layer into two equal parts, a hand drill is provided. The hand drill is used to drill holes at intervals along the corresponding cutting lines. Then, steel wedges are provided and gradually driven into the drill holes to cause adjacent rock layers to crack along the corresponding cutting lines and to create horizontal cracks at the bottom of the rock layers.

5. The method for excavating boreholes for pier foundations in complex mountainous soil and rock layers according to claim 1, characterized in that: The drilling tool is a water-cooled drill.

6. The method for excavating boreholes for pier foundations in complex mountainous soil and rock layers according to claim 1, characterized in that: After the rock strata are excavated and the foundation hole is formed, the inner wall of the foundation hole is modified to form a smooth and continuous arc surface.

7. The method for excavating boreholes for pier foundations in complex mountainous soil and rock layers according to claim 1, characterized in that: Before excavating the soil layer, the soil layer is divided into multiple upper and lower sections. During excavation, the soil layers are excavated sequentially from top to bottom.

8. The method for excavating boreholes for pier foundations in complex mountainous soil and rock layers according to claim 7, characterized in that: Before excavating the soil layer, a well ring lock is installed on the soil layer along the edge of the excavation area; during excavation, the soil layer inside the well ring lock is excavated; after the foundation hole of the pier is completed, the well ring lock is removed.

9. A method for excavating boreholes for pier foundations in complex mountainous soil and rock layers according to claim 7, characterized in that: After each section of soil is excavated, steel bars and formwork are provided. The steel bars are placed on the wall of the excavated hole and covered with formwork. Then, concrete is poured into the formwork to form a retaining wall. After the retaining wall reaches the design strength, the formwork is removed and the next section of soil is excavated.

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