CN109629556B - Pier variable cross-section vibration isolation pile foundation and construction method thereof - Google Patents

Abstract

The invention discloses a bridge pier variable cross-section vibration isolation pile foundation and a construction method thereof. The upper section is composed of three vibration isolation layers, the first concrete layer, the first corrugated steel, and the first concrete retaining wall from the inside to the outside. The middle section is composed of a vibration isolation layer, the second vibration isolation layer, and the second concrete protective wall. The concrete layer, the second corrugated steel, the second concrete retaining wall, the lower section is the third concrete layer, the third corrugated steel, and the third concrete retaining wall from the inside to the outside, and the bottom of the lower section is closed. The advantages of the invention are: easy construction, reducing the cost of the bridge pier; the single pile structure of the bridge pier is simple, the force transmission path is clear, the displacement vibration of the pile top is adapted to the bending moment characteristics that gradually decrease from top to bottom; the vibration isolation layer When the vibration wave is spread to the surrounding soil, part of the vibration energy is consumed.

Description

A bridge pier variable cross-section vibration isolation pile foundation and its construction method

Technical field

The invention belongs to the technical field of bridge pile construction, and specifically relates to a bridge pier variable-section vibration isolation pile foundation and a construction method thereof.

Background technique

With the development of bridge facilities, the structure and construction environment of bridges are becoming more and more complex, thus placing increasingly stringent requirements on the stability of bridge piles. Existing bridge pier foundations are usually filled with reinforced concrete. The vibration resistance of the bottom of the above-mentioned structure is poor. When the bridge superstructure shakes, the bridge piers are difficult to provide sufficient vibration damping force, resulting in reduced bridge stability.

Contents of the invention

The object of the present invention is to provide a bridge pier variable cross-section vibration isolation pile foundation and its construction method based on the above-mentioned shortcomings of the prior art. By setting a three-layer variable cross-section supporting structure at the bottom of the steel pile, and in the supporting structure A vibration isolation layer is added to make the pile foundation have vibration resistance.

The purpose of the present invention is achieved by the following technical solutions:

A bridge pier variable cross-section vibration isolation pile foundation, which is characterized in that it includes a steel pile and an upper section, a middle section, and a lower section arranged around the steel pile in sequence from top to bottom, and the upper section From the inside to the outside, there are three vibration isolation layers, the first concrete layer, the first corrugated steel, and the first concrete retaining wall. The middle section is the vibration isolation layer, the second concrete layer, and the first concrete protective wall. There are two corrugated steel and a second concrete retaining wall. From the inside to the outside, the lower section is a third concrete layer, the third corrugated steel and the third concrete retaining wall. The bottom of the lower section is closed.

The vibration isolation layer includes an inner concrete layer and an outer high-damping rubber layer.

An anchor support is provided outside the middle section. The anchor support includes a plurality of horizontal anchors. One end of the anchor is inserted into the soil horizontally and the other end is connected to the second concrete retaining wall. .

The anchor rods are arranged in a ring at different heights around the periphery of the second concrete retaining wall.

The upper segment, the middle segment, and the lower segment are all annular structures.

A construction method involving any one of the described bridge pier variable cross-section vibration isolation pile foundations, characterized in that the working method includes the following steps: determine the construction location after measurement; dig pile holes according to the construction location, and The first corrugated steel is implanted in the hole wall of the corresponding depth of the segment, and the first concrete retaining wall is filled between the soil and the first corrugated steel; the second corrugated steel is implanted in the hole wall of the corresponding depth of the middle segment. , fill a second concrete retaining wall between the soil and the second corrugated steel; implant a third corrugated steel in the hole wall of the corresponding depth in the lower section, between the soil and the third corrugated steel A third concrete protective wall is filled between the steels; a first concrete layer and three vibration isolation layers are filled in sequence inside the first corrugated steel, and a second concrete layer and one layer of vibration isolation layer are filled in sequence inside the second corrugated steel. For the vibration isolation layer, a third concrete layer is filled inside the third corrugated steel; steel piles are placed and the pile holes are backfilled.

Before implanting the second corrugated steel, set up anchor support at the depth of the middle section, and when filling the second concrete retaining wall, fix the anchor end of the anchor support at in the second concrete retaining wall.

The advantages of the invention are: (1) Convenient construction, fast construction speed, significant savings in steel bars and concrete materials, and reduced cost of the bridge pier; (2) The single pile structure of the bridge pier is simple, the force transmission path is clear, and the displacement vibration of the pile top is reduced. Compatible with the bending moment characteristics that gradually decrease from top to bottom; (3) When the vibration isolation layer diffuses vibration waves to the surrounding soil, it consumes part of the vibration energy.

Description of the drawings

Figure 1 is a schematic cross-sectional structural diagram of a variable-section vibration isolation pile foundation for a bridge pier in an embodiment of the present invention.

Detailed ways

The features and other related features of the present invention will be further described in detail through examples in conjunction with the accompanying drawings to facilitate the understanding of those skilled in the industry:

As shown in Figure 1, the marks in the figure are: steel pile 1, upper section 2, middle section 3, lower section 4, first concrete layer 5, first corrugated steel 6, first concrete retaining wall 7, The second concrete layer 8, the second corrugated steel 9, the second concrete retaining wall 10, the third concrete layer 11, the third corrugated steel 12, the third concrete retaining wall 13, the concrete layer 14, the high damping rubber layer 15 and the anchor rod 16.

Embodiment: As shown in Figure 1, this embodiment specifically relates to a bridge pier variable cross-section vibration isolation pile foundation and its construction method. By setting a three-layer variable cross-section supporting structure at the bottom of the steel pile 1, and in the supporting structure A vibration isolation layer is added to make the pile foundation anti-vibration.

As shown in Figure 1, the variable-section vibration isolation pile foundation of the bridge pier in this embodiment includes a steel pile 1 and an upper section 2, a middle section 3, and a lower section that are arranged around the steel pile 1 from top to bottom. Section 4, the upper section 2 is composed of three layers of vibration isolation layer, the first concrete layer 5, the first corrugated steel 6, and the first concrete retaining wall 7 from the inside to the outside. The middle section 3 is composed of one layer of isolation layer from the inside to the outside. The vibration layer, the second concrete layer 8, the second corrugated steel 9, the second concrete retaining wall 10, the lower section 4 from the inside to the outside is the third concrete layer 11, the third corrugated steel 12, the third concrete retaining wall 13, the lower section The bottom of segment 4 is closed. The upper segment 2, the middle segment 3, and the lower segment 4 are all annular structures. The cross-sectional area of the upper segment 2 to the lower segment 4 gradually decreases, forming a bending moment characteristic that gradually decreases from top to small. Since the maximum displacement of the pile foundation occurs at the pile top, and the maximum bending moment also occurs at the pile top when the pile top is fixed, the above-mentioned variable cross-section pile foundation structure also adapts to the bending moment characteristics from the pile top to the pile bottom. Since the vibration of the bridge is transmitted from top to bottom, three layers of vibration isolation layers are provided through the upper segment 2 and one layer of vibration isolation layer in the middle segment 3, so that when the vibration wave spreads to the surrounding soil, there are two parts of energy consumption.

As shown in Figure 1, in this embodiment, each vibration isolation layer includes an inner concrete layer 14 and an outer high-damping rubber layer 15. The vibration waves caused by bridge vibration are attenuated by refraction and reflection on different media surfaces of the vibration isolation layer, and there is also a damping energy dissipation effect in high-damping rubber. The upper section 2 is composed of concrete layer 14, high-damping rubber layer 15, concrete layer 14, high-damping rubber layer 15, concrete layer 14, high-damping rubber layer 15, concrete layer 14, corrugated steel, and concrete retaining wall from the inside to the outside; The middle section 3 is composed of concrete layer 14, high-damping rubber layer 15, concrete layer 14, corrugated steel, and concrete retaining wall from the inside to the outside; the lower section 4 is composed of concrete layer 14, corrugated steel, and concrete retaining wall from the inside to the outside.

As shown in Figure 1, in this embodiment, the middle section 3 is provided with anchor support on the outside. The anchor support includes a plurality of horizontally arranged anchor rods 16. One end of the anchor rod 16 is inserted into the soil horizontally, and the other end is connected to on the second concrete retaining wall 10. The anchor rods 16 are arranged annularly at different heights around the periphery of the second concrete retaining wall 10 . The anchor support can enhance the stability of the middle section 3 and effectively avoid the instability caused by the sudden reduction in the size of the upper section 2 and the middle section 3.

As shown in Figure 1, the construction method of the variable-section vibration isolation pile foundation of the bridge pier in this embodiment includes the following steps: determine the construction location after measurement. The construction location is composed of the pile axis and the edge line of the excavation section. Pile holes are excavated according to the construction location. The drilling and blasting method is used for excavation. Variable cross-section excavation is carried out in sections from top to bottom, and the upper section 2, the middle section 3, and the lower section 4 are excavated in sequence. The first corrugated steel 6 is implanted in the hole wall of the corresponding depth in the upper section 2, and the first concrete retaining wall 7 is filled between the soil and the first corrugated steel 6; the first corrugated steel 6 is implanted in the hole wall of the corresponding depth in the middle section 3 Insert the second corrugated steel 9, and fill the second concrete retaining wall 10 between the soil and the second corrugated steel 9; fill the first concrete layer 5 and the third vibration isolation layer inside the first corrugated steel 6 in turn. The second concrete layer 8 and a vibration isolation layer are filled in the inner side of the second corrugated steel 9 in turn, and the third concrete layer 11 is filled in the inner side of the third corrugated steel 12; the steel pile 1 is put in and the pile hole is backfilled. Before implanting the second corrugated steel 9, set up anchor support at the depth of the middle section 3, and when filling the second concrete retaining wall 10, fix the anchor end of the anchor support in the second concrete retaining wall. .

This embodiment has the following advantages: construction is convenient, construction speed is fast, steel bars and concrete materials are greatly saved, and the cost of the bridge pier is reduced; the single pile structure of the bridge pier is simple, the force transmission path is clear, and the displacement vibration of the top of the pile is closely related to the small one from top to bottom. It adapts to the gradually shrinking bending moment characteristics; when the vibration isolation layer diffuses vibration waves to the surrounding soil, it consumes part of the vibration energy.

Claims (5)

1. The bridge pier variable cross-section vibration isolation pile foundation is characterized by comprising a steel pile, an upper section, a middle section and a lower section, wherein the upper section, the middle section and the lower section are sequentially arranged on the periphery of the steel pile in a surrounding manner from top to bottom, the upper section sequentially comprises three layers of vibration isolation layers, a first concrete layer, first corrugated steel and a first concrete retaining wall from inside to outside, the middle section sequentially comprises a layer of vibration isolation layer, a second concrete layer, second corrugated steel and a second concrete retaining wall from inside to outside, the lower section sequentially comprises a third concrete layer, a third corrugated steel and a third concrete retaining wall from inside to outside, and the bottom of the lower section is closed;

the vibration isolation layer comprises an inner concrete layer and an outer high damping rubber layer; the middle section outside is provided with the anchor bolt support, the anchor bolt support includes a plurality of anchor rods that the level set up, the one end level of anchor rod inserts the soil body, and the other end is connected on the second concrete dado.

2. The pier variable cross-section vibration isolation pile foundation according to claim 1, wherein the anchor rods are annularly arranged at the periphery of the second concrete retaining wall at different heights.

3. The pier variable cross-section vibration isolation pile foundation of claim 1, wherein the upper section, the middle section and the lower section are all of annular structures.

4. A construction method relating to the pier variable cross-section vibration isolation pile foundation of any one of claims 1 to 3, characterized in that the construction method comprises the following steps: measuring and then determining a construction position; digging a pile hole according to the construction position, implanting first corrugated steel into a hole wall with the depth corresponding to the upper section, and filling a first concrete retaining wall between a soil body and the first corrugated steel; implanting second corrugated steel into the hole wall with the middle section corresponding to the depth, and filling a second concrete retaining wall between the soil body and the second corrugated steel; a third corrugated steel is implanted into the hole wall with the depth corresponding to the lower section, and a third concrete retaining wall is filled between the soil body and the third corrugated steel; sequentially filling a first concrete layer and three vibration isolation layers on the inner side of the first corrugated steel, sequentially filling a second concrete layer and one vibration isolation layer on the inner side of the second corrugated steel, and filling a third concrete layer on the inner side of the third corrugated steel; and placing the steel piles and backfilling the pile holes.

5. The construction method of a pier variable cross-section vibration isolation pile foundation according to claim 4, wherein an anchor bolt support is installed in the middle section depth before the second corrugated steel is implanted, and an anchor bolt end of the anchor bolt support is fixed in the second concrete retaining wall when the second concrete retaining wall is filled.