阅读说明：本技术 一种适用于山区的环形截面岩石基础及其施工方法 (Annular-section rock foundation suitable for mountainous area and construction method thereof ) 是由 邹峥 王玉雷 周旸 李聚昭 刘伟 程鹏 张建伟 张东亮 于 2021-08-20 设计创作，主要内容包括：本发明公开了一种适用于山区的环形截面岩石基础及其施工方法,其包含地表、基础环形柱体、混凝土实心柱体和地脚螺栓；该基础环形柱体位于地表下方；该混凝土实心柱体嵌入该基础环形柱体与地表之间的实心柱体基坑内,且位于该基础环形柱体的正上方；该基础环形柱体由环形基槽及被环形基槽环绕的岩体构成；该环形基槽的槽内放置有钢筋笼,并浇灌有混凝土；该钢筋笼高度大于该环形基槽的槽内深度与该实心柱体基坑深度之和,但该钢筋笼高度小于该基础环形柱体高度与该混凝土实心柱体高度之和；该地脚螺栓包含固定端；该固定端与所需固定设备相连接。本发明的施工方法解决了基坑开挖困难、施工方法复杂、施工安全隐患较高、机械化程度低、经济性较差的问题。(The invention discloses an annular section rock foundation suitable for mountainous areas and a construction method thereof, wherein the annular section rock foundation comprises a ground surface, a foundation annular cylinder, a concrete solid cylinder and foundation bolts; the basic annular column body is positioned below the ground surface; the concrete solid column is embedded in a solid column foundation pit between the foundation annular column and the ground surface and is positioned right above the foundation annular column; the basic annular column body consists of an annular base groove and a rock mass surrounded by the annular base groove; a reinforcement cage is placed in the groove of the annular foundation groove, and concrete is poured in the reinforcement cage; the height of the reinforcement cage is greater than the sum of the depth of the annular foundation trench and the depth of the solid column foundation pit, but the height of the reinforcement cage is less than the sum of the height of the foundation annular column and the height of the concrete solid column; the anchor bolt comprises a fixed end; the fixed end is connected with the required fixing equipment. The construction method solves the problems of difficult excavation of the foundation pit, complex construction method, higher potential safety hazard of construction, low mechanization degree and poorer economy.)

1. A rock foundation with an annular cross section suitable for a mountainous area is arranged on the ground surface (1) and is characterized by comprising a foundation annular column body (2), a concrete solid column body (3) and foundation bolts (4); the basic annular column body (2) is positioned below the earth surface (1); the concrete solid column (3) is embedded in a solid column foundation pit (5) between the foundation annular column (2) and the ground surface (1) and is positioned right above the foundation annular column (2);

the basic annular column body (2) consists of an annular base groove (21) and a rock body (22) surrounded by the annular base groove (21); a reinforcement cage (23) is arranged in the groove of the annular base groove (21), and concrete is poured in the groove; the height of the reinforcement cage (23) is greater than the sum of the depth of the annular foundation trench (2) and the depth of the solid column foundation pit (5), and the height of the reinforcement cage (23) is less than the sum of the height of the foundation annular column (2) and the height of the concrete solid column (3);

the anchor bolt (4) comprises a fixed end (42); the fixed end (42) is connected to the desired fixture.

2. The annular cross-section rock foundation as claimed in claim 1, wherein the concrete solid column (3) has a cross-section of circular or square shape and a length of 1.0-1.5 m.

3. An annular cross-section rock foundation for mountainous areas as claimed in claim 1, wherein the outer contour of the foundation annular cylinder (2) is circular or square.

4. An annular-section rock foundation suitable for mountainous areas as claimed in claim 1, wherein the concrete is a compacted mixture of fine-stone concrete and an expanding agent.

5. An annular-section rock foundation suitable for mountainous areas as claimed in claim 1, wherein the width of the concrete solid column (3) is greater than or equal to the width of the foundation annular column (2).

6. An annular cross-section rock foundation for mountainous areas as claimed in claim 1, wherein the anchor bolt (4) is provided with an anchoring end (41) on the side opposite to the fixing end (42), the anchoring end (41) being provided inside the concrete solid column (3).

7. A construction method of an annular section rock foundation suitable for mountainous areas is characterized by at least comprising the following steps:

step 1, excavating a solid column foundation pit (5) at a construction position;

step 2, mechanically excavating an annular foundation trench (21) at the bottom of the solid column foundation pit (5), and reserving a rock mass (22) at the middle part;

step 3, placing a reinforcement cage (23) in the groove of the annular base groove (21);

step 4, pouring concrete into the groove of the annular base groove (21) and vibrating to compact;

step 5, fixing the anchoring end (41) of the foundation bolt (4) in a pit of the solid column foundation pit (5);

and 6, pouring concrete into the pit of the solid column foundation pit (5) until the reinforcing cage (23) is covered but the fixed end (42) of the foundation bolt (4) cannot be covered, and forming the concrete solid column (3) after the concrete is solidified.

Technical Field

The invention relates to the field of power transmission line construction, in particular to an annular section rock foundation suitable for mountainous areas and a construction method thereof.

Background

The mountain areas in China are widely distributed. In mountainous areas, large machinery for existing foundation construction is difficult to enter and unfold due to the inconvenience of road transportation, and the popularization of mechanized construction in the power transmission line industry is seriously hindered.

The existing power transmission line foundation in the mountainous area generally adopts a rock embedded foundation and a hole digging foundation, and the two foundation types generally have the following problems:

1. the construction method is complicated. When the manual excavation operation mode is adopted, a concrete retaining wall needs to be arranged for guaranteeing personal safety, the excavation of the next section of foundation pit can be carried out only after one section of concrete of the retaining wall is finally solidified, the construction interruption frequency is high, and the consumed time is long;

2. the construction potential safety hazard is higher. When the manual hole drilling operation is carried out, toxic gas seeps out of the rock body or is in an oxygen deficiency state, and once an emergency occurs, the rescue difficulty is high and the safety is low due to the fact that the operation space is narrow.

3. The mechanization degree is low. The hole digging foundation of the mountain rock foundation is generally constructed by adopting a rotary drilling rig during mechanized construction, the self weight of construction machinery is large (about 40-70 t), and the construction machinery is difficult to enter the field, so that the mechanized construction proportion of the foundation type is low. The conventional mountain rock foundation usually adopts an excavation mode combining manual excavation and blasting construction, and the mode is long in construction period and high in construction difficulty.

4. The economy is poor. In order to provide a manual operation space, the pile diameter is designed to be 1.2m at least, the concrete consumption is high, and the concrete consumption of a single-foundation is about 20 to E160m³The consumption of concrete is high, and the transportation difficulty of materials is high;

5. the remaining soil is difficult to treat. The residual soil amount generated by foundation pit excavation is basically equivalent to the basic concrete amount, local spreading treatment can be adopted for mountainous areas with slow gradient, and outward transportation and comprehensive utilization are needed for mountainous areas with steep gradient, so that the treatment is quite difficult;

in addition, the surface layer of the mountain area is shallow, and deep natural bedrock is widely existed in the lower layer. Natural rock often has higher strength and better durability than concrete through physical and chemical diagenesis. At present, the conventional rock embedded foundation and the conventional hole digging foundation in the power transmission line are all cast with columnar concrete in a mode of digging out all rocks in the middle of a foundation pit, the self strength of bedrock cannot be fully utilized, the excavation amount of the foundation pit and the surplus soil outward transportation amount are increased, and the construction and environmental protection cost is high.

Disclosure of Invention

In order to solve the problems, the invention provides the annular section rock foundation suitable for the mountainous area and the construction method thereof, and solves the problems of difficult excavation of the foundation pit, complex construction method, higher potential safety hazard of construction, low mechanization degree and poorer economy.

The technical means adopted by the invention are as follows.

A rock foundation with an annular cross section suitable for a mountainous area is arranged on the ground surface and is characterized by comprising a foundation annular column body, a concrete solid column body and foundation bolts; the basic annular column body is positioned below the ground surface; the concrete solid column is embedded in a solid column foundation pit between the foundation annular column and the ground surface and is positioned right above the foundation annular column;

the basic annular column body consists of an annular base groove and a rock mass surrounded by the annular base groove; a reinforcement cage is placed in the groove of the annular foundation groove, and concrete is poured in the groove; the height of the reinforcement cage is greater than the sum of the depth of the annular foundation trench and the depth of the solid column foundation pit, and the height of the reinforcement cage is less than the sum of the height of the foundation annular column and the height of the concrete solid column;

the anchor bolt comprises a fixed end; the fixed end is connected with the required fixing equipment.

Preferably, the cross section of the concrete solid column body can be circular or square, and the length of the concrete solid column body is 1.0-1.5 m.

Preferably, the base annular cylinder may be circular or square in its outer contour. Preferably, the concrete is a mixture of fine stone concrete and an expanding agent after being vibrated and compacted.

Preferably, the width of the concrete solid column is greater than or equal to the width of the foundation annular column.

Preferably, the anchor bolt is provided with an anchoring end on the side opposite to the fixed end, and the anchoring end is arranged inside the concrete solid column body.

The invention also discloses a construction method of the annular section rock foundation suitable for mountainous areas, which at least comprises the following steps:

step 1, excavating a solid column foundation pit at a construction position;

step 2, mechanically excavating an annular foundation trench at the bottom of the solid column foundation pit, and reserving a rock mass in the middle part;

step 3, placing a reinforcement cage in the groove of the annular base groove;

step 4, pouring concrete into the groove of the annular base groove and vibrating to compact the concrete;

step 5, fixing the anchoring end of the foundation bolt in a pit of the solid column foundation pit;

and 6, pouring concrete into the pit of the solid column foundation pit until the reinforcing cage is covered but the fixed end of the foundation bolt cannot be covered, and forming a concrete solid column after the concrete is solidified.

The invention has the following beneficial effects:

1. the self strength of the bedrock can be utilized to the maximum extent, and the bearing capacity of the foundation is improved;

2. the consumption of the foundation concrete, the excavation amount of the foundation pit and the external transportation amount of the residual soil are reduced, and the aim of resource conservation and environmental friendliness is fulfilled;

3. the small drilling machine is convenient to transport, the utilization rate of the machine can be improved to a greater extent, the labor input is reduced, and the construction risk is reduced;

4. can obviously shorten the construction period and has better social and economic benefits.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic structural view of the basic annular column of the present invention.

Fig. 3 is a schematic cross-sectional view of the basic annular column of the present invention.

Description of the figure numbers: the foundation comprises a ground surface 1, a foundation annular column 2, a concrete solid column 3, foundation bolts 4, a solid column foundation pit 5, an annular foundation groove 21, a rock body 22, a reinforcement cage 23, an anchoring end 41 and a fixing end 42.

Detailed Description

Referring to fig. 1 to 3, the present invention provides a schematic structural diagram of a rock foundation with a circular cross section suitable for mountainous areas, which is disposed on a ground surface 1 and includes a foundation circular column 2, a concrete solid column 3 and anchor bolts 4.

The foundation annular cylinder 2 is located below the ground surface 1, the outline of the foundation annular cylinder 2 can be circular or square, the concrete solid cylinder 3 is embedded into a solid cylinder foundation pit 5 between the foundation annular cylinder 2 and the ground surface 1 and is located right above the foundation annular cylinder 2, the cross section of the concrete solid cylinder 3 can be circular or square, and the length of the concrete solid cylinder is about 1.0-1.5 m on the basis of meeting the anchoring length of foundation bolts. The width of the concrete solid column 3 is greater than or equal to the width of the foundation annular column 2.

The basic annular column body 2 consists of an annular base groove 21 and a rock body 22 surrounded by the annular base groove 21; a reinforcement cage 23 is placed in the groove of the annular foundation groove 21, and concrete is poured in the groove, wherein the concrete is a mixture of fine aggregate concrete and an expanding agent after being vibrated and compacted; the height of the reinforcement cage 23 is greater than the sum of the depth of the annular foundation trench 2 and the depth of the solid column foundation pit 5, and the height of the reinforcement cage 23 is less than the sum of the height of the annular foundation column 2 and the height of the solid concrete column 3; the anchor bolt 4 comprises a fixing end 42, the fixing end 42 is connected with a required fixing device, an anchoring end 41 is arranged on the side of the anchor bolt 4 opposite to the fixing end 42, and the anchoring end 41 is arranged inside the concrete solid column 3.

In the actual construction, a solid column foundation pit 5 meeting the anchoring length of the anchor bolt 4 is excavated from the ground surface downwards in advance of the desired construction position, an annular foundation groove 21 is excavated at the bottom of the foundation pit by using a small drilling machine and taking a rock mass 22 as the center, a reinforcement cage 23 is placed in the groove of the annular foundation groove 21, concrete is poured into the groove, and the concrete is a mixture of fine aggregate concrete and an expanding agent after being vibrated and compacted.

The height of the placed reinforcement cage 23 is larger than the sum of the depth of the annular foundation trench 2 and the depth of the solid column foundation pit 5, and one end of the reinforcement cage 23 is positioned above the ground surface 1.

The anchoring end 41 of the anchor bolt 4 is fixed to the solid column foundation pit 5, the fixing end 42 of the anchor bolt 4 is located above the ground surface 1, and the length of the anchor bolt 4 above the ground surface 1 is greater than the length of the reinforcement cage 23 above the ground surface 1.

After the foundation bolts 4 are fixed, the concrete is poured into the solid column foundation pit 5, and the height of the reinforcement cage 23 is smaller than the sum of the height of the foundation annular column 2 and the height 3 of the concrete solid column, so that the concrete can not cover the fixed ends 42 of the foundation bolts 4 until the reinforcement cage 23 is covered, and the concrete forms the concrete solid column 3 after being solidified.

The basic annular column body 2 can be circular or square according to the actual construction requirement.

The cross-sectional shape of the concrete solid column 3 can be circular or square according to the actual construction requirement, the length is about 1.0-1.5 m on the basis of meeting the anchoring length of the foundation bolt 4, and the width of the concrete solid column is larger than or equal to that of the foundation annular column 2.