CN101691760A - Composite foundation combining anchor rods with excavation and construction method thereof - Google Patents

Abstract

The invention provides an anchor-bolt combined excavation composite foundation and a construction method thereof, which are mainly applied to transmission line tower foundations. The composite foundation is jointly formed by a combined anchor foundation and an excavation foundation, including an excavation foundation part and an anchor The foundation part, the bolt foundation part is located in the rock formation on the ground surface, including at least one cylindrical or polygonal rock bolt, the rock bolt has a main reinforcement of the bolt and concrete or cement mortar surrounding the main reinforcement of the bolt, the The main reinforcement of the anchor rod extends into the excavated foundation part; the excavated foundation part is located in the soil layer on the ground surface and is composed of reinforcement and concrete; Anchor main reinforcement connection in section. And provide a specific construction method.

Description

A composite foundation with bolt joint digging and its construction method

technical field

The invention relates to the technical field of foundation construction of power transmission lines, in particular to a bolt-bolt combined excavation composite foundation and a construction method thereof.

Background technique

In the foundation of transmission lines, it is often encountered that the shallow layer is the soil layer, and the deeper layer is the rock layer. Under such geological conditions, the foundation form used before is generally excavation and backfill foundation (large slab foundation, stepped foundation) foundation) or excavation foundation, when the line load is large, the depth of the bottom surface of the foundation needs to exceed the top surface of the rock layer, and the bearing capacity of the foundation can meet the load requirements of the line. Large slab foundations and stepped foundations require methods such as blasting of the rock strata to excavate the rock strata, which brings great difficulty to the construction. At the same time, there is a huge amount of earth excavation, which destroys the undisturbed soil and is not conducive to environmental protection.

Contents of the invention

In order to overcome the deficiencies in the prior art, the object of the present invention is to provide a bolt-bolt combined excavation and excavation composite foundation without blasting rock formations, which is convenient for construction and reduces the amount of earthwork excavation. It is mainly applied to the foundation of power transmission line poles and towers.

Another object of the present invention is to provide a construction method for bolt combined digging and excavation composite foundation.

For this reason, the present invention proposes a kind of bolt joint digging compound foundation, comprises digging foundation and bolt foundation, and described bolt foundation is positioned at the rock stratum of ground surface, and it comprises at least one cylindrical or polygonal rock bolt , the rock bolt has a main reinforcement of the anchor rod and concrete or cement mortar around the main reinforcement of the anchor rod, and the main reinforcement of the anchor rod extends into the excavated foundation; and concrete; the excavation foundation and the anchor foundation are connected by the main reinforcement of the anchor extending into the excavation foundation.

Wherein, the length of the main reinforcement of the anchor rod extending into the digging foundation is greater than or equal to 40 times the diameter of the main reinforcement of the anchor rod.

Wherein, the height h of the top surface of the concrete or cement mortar surrounding the main reinforcement of the anchor rod protruding into the digging foundation is greater than or equal to 10 cm.

Wherein, the cross-sectional shape of the excavation foundation in the vertical direction is an inverted funnel shape or a rectangle or a trapezoid whose upper base is longer than the lower base.

The present invention also provides a construction method for bolt combined excavation and excavation composite foundation, the construction process is as follows:

1) Forming a hole, using a bolter to drill a bolt hole in the soil layer and rock layer on the surface;

2) After the hole is formed, put and fix the main reinforcement of the anchor rod, so that the main reinforcement of the anchor rod extends into the excavation foundation part and the length is greater than or equal to 40 times the diameter of the main reinforcement of the anchor rod, and then pour the anchor rod part Concrete or cement mortar surrounding the main reinforcement of the anchor rod, so that the top surface of the concrete or cement mortar surrounding the main reinforcement of the anchor rod protrudes into the digging foundation part to a height greater than or equal to 10 cm;

3) Excavate and excavate the foundation pit of excavating the foundation part at the soil layer part of the ground surface;

4) Place and fix the reinforcement of the excavated foundation part on the excavated foundation part, and then pour concrete.

The anchor bolt combined digging and excavation composite foundation of the present invention can be used in geological conditions where the shallow layer is the soil layer and the deeper layer is the rock layer. It is mainly applied to the tower foundation of the transmission line. The composite foundation is jointly formed by the anchor bolt foundation and the excavation foundation. Since the bottom surface of the excavated foundation is placed on the top surface of the rock formation, the excavated foundation bears the main downward pressure when the force is applied, and the excavated foundation and the anchor foundation jointly bear the uplift force and horizontal force, so that the load requirements of the transmission line can be met. .

The beneficial effect of the present invention is that: the bolt-bolt combined excavation and excavation composite foundation does not need to blast the rock formation, which is convenient for construction, reduces the amount of earthwork excavation, utilizes undisturbed soil, and is beneficial to protect the environment.

Description of drawings

Fig. 1 is the structural representation of the large slab foundation or stepped foundation of prior art;

Fig. 2 is the first kind of structure schematic diagram of the anchor rod joint excavation and excavation composite foundation of the present invention;

Fig. 3 is the schematic flow sheet of the composite foundation and construction method thereof of the anchor rod joint excavation of the present invention;

Fig. 4 is a schematic diagram of specific structural dimensions of Fig. 2, wherein Fig. 4-1 is a cross-sectional view of Fig. 2, and Fig. 4-2 is a top view of Fig. 2;

Fig. 5 is the second kind of structure schematic diagram of the anchor rod joint excavation and excavation composite foundation of the present invention;

Fig. 6 is the third structure schematic diagram of the anchor rod combined excavation and excavation composite foundation of the present invention;

Among them, I-soil layer, II-rock layer, 1-excavation foundation, 2-bolt foundation, 3-rock bolt, 4-bolt main reinforcement, 5-concrete or cement mortar around the main reinforcement of the bolt, 6-fitting Reinforcement, 7-concrete, 8-anchor drilling, 9-excavation of the foundation pit of the foundation.

Detailed ways

Below in conjunction with accompanying drawing, the composite foundation of bolt combined excavation of the present invention will be further described.

As shown in Fig. 2, the composite foundation of bolt joint digging of the present invention comprises digging foundation 1 and bolt foundation 2, and described bolt foundation 2 is located in the rock formation II of ground surface, and it comprises at least one cylindrical or polygonal A rock bolt 3, the rock bolt 3 has a main reinforcement 4 and concrete or cement mortar 5 around the main reinforcement of the anchor, the main reinforcement 4 of the anchor extends into the excavated foundation 1; the excavated foundation 1 is located on the ground surface In the soil layer I, the bottom surface of the excavated foundation 1 is placed on the top surface of the rock formation II, which is composed of reinforcement 6 and concrete 7; The rod main reinforcement 4 is connected, and the cross-sectional shape of the digging foundation 1 in the vertical direction is an inverted funnel shape. As shown in Figures 5-6, the cross-sectional shape of the digging foundation 1 in the vertical direction can also be a rectangle or a trapezoid whose upper side is longer than the lower side.

As shown in Figure 4, the structure size of the bolt joint digging composite foundation of the present invention can adopt the following parameters: the soil layer I is a loess layer, and the rock layer II below the soil layer is a slightly weathered rock layer, and the digging foundation 1 The upper narrow end has a diameter of 0.8m and a length of 1m; the lower enlarged end has a diameter of 1.2cm and a length of 0.5m. The upper digging foundation 1 is located in the 1.5m thick loess layer. Set four rock bolts 3 arranged in a square in the micro-weathered rock stratum. The distance between the rock bolts 3 is 40cm, and its diameter is 0.15m. The concrete or cement mortar 5 around the anchor rod main reinforcement 4 adopts C20 concrete or M20 cement mortar. The length of the main reinforcement of the anchor rod entering the excavated foundation is 1.44m. The composite foundation with combined digging and excavation of anchor rods can withstand a pull-up force of 150 tons.

Figure 3 shows a schematic diagram of the construction of the foundation of the present invention. The specific construction process is as follows:

1) Forming a hole, using a bolter to drill a bolt hole in the soil layer and rock layer on the surface;

2) After the hole is completed, put and fix the main reinforcement of the anchor rod, so that the main reinforcement of the anchor rod extends into the excavation foundation and the length is greater than or equal to 40 times the diameter of the main reinforcement of the anchor rod, and then pour the part of the anchor rod around The concrete or cement mortar of the main reinforcement of the anchor rod, so that the top surface of the concrete or cement mortar surrounding the main reinforcement of the anchor rod extends into the digging foundation to a height greater than or equal to 10 cm;

3) Excavate and excavate the foundation pit of excavating the foundation at the soil layer part of the surface;

4) Place and fix the excavated foundation reinforcement on the excavated foundation, and then pour concrete.

In addition, the bolt foundation, stepped foundation, large slab type, and excavated foundation described in the present invention are all known foundation forms, which are often used for power transmission line foundations.

Fig. 5 is a schematic diagram of the second structure of the composite foundation with combined digging of bolts according to the present invention, and Fig. 6 is a schematic diagram of the third configuration of the composite foundation with combined digging of bolts according to the present invention. Wherein, the cross-sectional shape of the excavation foundation in the vertical direction is an inverted funnel shape or a rectangle or a trapezoid whose upper base is longer than the lower base.

The invention has been described herein in terms of specific exemplary embodiments. Appropriate substitutions or modifications will be apparent to those skilled in the art without departing from the scope of the present invention. The exemplary embodiments are illustrative only, and not limiting of the scope of the invention, which is defined by the appended claims.

Claims (5)

1. composite foundation combining anchor rods with excavation, comprise digging foundation (1) and anchor pole basis (2), it is characterized in that: described anchor pole basis (2) is arranged in the rock stratum (II) on the face of land, it comprises at least one cylindrical or polygonal rock bolt (3), described rock bolt (3) has anchor pole master muscle (4) and centers on the concrete or the cement mortar (5) of anchor pole master muscle, and described anchor pole master muscle (4) extend in the digging foundation (1); Described digging foundation (1) is arranged in the soil layer (I) on the face of land, and it is made of arrangement of reinforcement (6) and concrete (7); Described digging foundation (1) is connected by the anchor pole master muscle (4) that extend in the digging foundation with anchor pole basis (2).

2. composite foundation combining anchor rods with excavation as claimed in claim 1 is characterized in that: the length that described anchor pole master muscle (4) extend into digging foundation (1) is more than or equal to 40 times of anchor pole master muscle (4) diameter.

3. composite foundation combining anchor rods with excavation as claimed in claim 1 or 2 is characterized in that: described around anchor pole master muscle concrete or the end face of cement mortar (5) extend into the height h of digging foundation (1) more than or equal to 10 centimetres.

4. as the described composite foundation combining anchor rods with excavation of claim 1-3, it is characterized in that: described digging foundation (1) is the infundibulate of back-off or rectangle or top at the cross sectional shape of vertical direction and is longer than following trapezoidal.

5. job practices as the described composite foundation combining anchor rods with excavation of claim 1-4, construction process is as follows:

1) pore-forming utilizes jumbolter to get out armature boring in the soil layer on the face of land and rock stratum;

2) after pore-forming finishes, put into and fixing described anchor pole master muscle, make described anchor pole master muscle extend into digging foundation length partly 40 times greater than anchor pole master muscle diameter, pour into described anchor pole then partly around the concrete or the cement mortar of anchor pole master muscle, make describedly to extend into the height of digging foundation part greater than 10 centimetres around the concrete of anchor pole master muscle or the end face of cement mortar;

3) partly draw the foundation ditch that digs out the digging foundation part at the soil layer on the face of land;

4) partly lay and fixing described digging foundation part arrangement of reinforcement, concreting then at digging foundation.

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