CN-122013819-A - Protective structure of water power transmission line group pile and construction method thereof

CN122013819ACN 122013819 ACN122013819 ACN 122013819ACN-122013819-A

Abstract

The invention discloses a protection structure of a pile group of a water transmission line and a construction method thereof, which relate to the technical field of pile group protection structures and comprise a protection layer arranged on a river bed layer, wherein pile group piles penetrate through the protection layer and penetrate into the river bed layer, the tops of the pile group piles are provided with rigid bearing platforms, the protection layer, the pile group piles and the river bed layer are stacked along the vertical direction, the protection layer is positioned between the pile group piles and the river bed layer, the protection layer comprises a bagged sand layer, a reverse filtering layer and a block stone layer which are sequentially paved on the pretreated river bed layer from bottom to top, and the protection layer is divided into a core area, a permanent protection area and a protection zone according to the protection importance.

Inventors

LIU FEI
DAN HANBO
LIU TI
Zhao Yingneng
HU JILEI
PAN YU
DING LEI
FENG HE
XU ZENG

Assignees

国网浙江省电力有限公司建设分公司
中国能源建设集团浙江省电力设计院有限公司

Dates

Publication Date: 20260512
Application Date: 20260130

Claims (10)

1. The utility model provides a transmission line group pile protective structure on water, its characterized in that, including setting up in the inoxidizing coating on the riverbed layer, group pile foundation runs through the inoxidizing coating and go deep into the riverbed layer, group pile foundation top is the rigidity cushion cap, the inoxidizing coating with group pile foundation and the riverbed layer stacks the setting along the vertical direction, the inoxidizing coating is located group pile foundation with between the riverbed layer, the inoxidizing coating includes sand layer in bags and reverse filter layer and the stone block layer of laying in proper order on the riverbed layer after the preliminary treatment from bottom to top, the inoxidizing coating is divided into one-core area, second grade-permanent protection area and tertiary-protection area according to the protection importance.
2. The water power transmission line pile group protection structure according to claim 1, wherein the primary-core area is an area where a pile group foundation is most easily washed out, the area is 1 time of a single pile diameter outside the pile group foundation, the secondary-permanent protection area is an area where a river bed is easily washed out, the area is 3 times of a single pile diameter outside the pile group foundation, the tertiary-protection area is an area for further improving the stability of a riprap structure, and the impact of water flow on the riprap is reduced by setting a slope angle, and the area is other areas outside the integral riprap layer structure core area and the permanent protection area.
3. The water transmission line pile group protection structure according to claim 1, wherein the bagged sand layer is a high-density polyethylene geotextile bag filled with graded sand, the packing compactness is required to be more than 90%, and the thickness of the bagged sand layer in the primary-core area is larger than that in other areas.
4. The water transmission line pile group protection structure according to claim 1, wherein the total thickness of the stone block layer is 2 to 3 times of the pile diameter of the pile group pile foundation single pile, and the thickness of the stone block layer is larger than that of other areas in the secondary-permanent protection area and the tertiary-guard area.
5. The water power transmission line pile group protection structure according to claim 1, wherein the rigid bearing platform is rigidly connected with the pile group pile foundation to form a high bearing platform pile group structure together.
6. The construction method of the water transmission line pile group protection structure according to claim 1, comprising the following steps: 1) Before construction, performing hydrogeological investigation on a target sea area to obtain a pile form factor, a pile foundation burial depth and a peripheral scouring history record according to a pile foundation design drawing, wherein the hydrogeological investigation comprises water depth, seabed soil quality type, wave parameters and water flow velocity; 2) The method comprises the steps of performing flattening treatment on a seabed in an initial construction stage, namely removing loose sediment or broken stone on a surface layer by using a dredger, then paving a bagged sand layer serving as a flexible substrate of a protective structure, arranging the bagged sand in rows and columns or in a delta-shaped manner by using a positioning ship during paving, controlling the distance between adjacent bag bodies to be 5-20 cm, determining the total thickness of the bagged sand layer according to the diameter of a pile foundation and the maximum flushing depth in a predicted non-protective state, and performing preliminary compaction after paving is finished to ensure that the flatness error of the substrate is less than 5 cm; 3) The method comprises the steps of paving a reverse filtering layer above a sand layer in bags, installing a flow velocity sensor near a pile foundation before the reverse filtering layer is constructed, collecting extreme water flow data of 100 years in a nearby hydrological station, and calculating a polishing Dan Lijing threshold value by combining pile foundation structural parameters; 4) The method comprises the steps of constructing a reverse filtering layer, paving a block stone layer above the reverse filtering layer, selecting high-strength natural rock or artificial broken stone as a block stone layer material, carrying out grading screening before throwing stones to determine the particle size of the thrown stones, transporting the block stones to a target area by adopting a dump barge during construction, accurately throwing the block stones through a positioning system to ensure that the block stones uniformly cover the surface of the reverse filtering layer, carrying out underwater inspection on each layer of thrown stones with the paving thickness of 50-80 cm by divers after paving, correcting local accumulation or void areas, determining the total thickness of the block stone layer according to the protection grade, and carrying out opposite impact on the void parts by adopting a high-pressure water gun to form a stable protection framework; 5) The construction method comprises the steps of installing a rigid bearing platform on the surface of a block stone layer after construction of the block stone layer is completed, firstly hoisting the rigid bearing platform to the surface of the block stone layer through a crane ship, arranging the rigid bearing platform according to determinant, controlling the distance between adjacent components to be 1-1.5 m, accurately penetrating a multi-layer protection structure through preset holes in the rigid bearing platform, reserving the holes in the prefabrication stage of the bearing platform, hoisting the bearing platform to the surface of the block stone layer on site to form a stable construction platform and a positioning template, then carrying out pile-group construction and realizing final stress conversion, penetrating a pile foundation of the pile group through the block stone layer, a reverse filtering layer and a bagged sand layer along the preset holes, finally anchoring the pile foundation in a river bed layer, wherein the anchoring depth is not less than 2m, monitoring the perpendicularity of the pile foundation of the pile group in real time, and realizing tight splicing of the rigid bearing platform through tenon joint or bolt connection in the horizontal direction to form a continuous rigid support network; 6) After construction, carrying out omnibearing quality detection on the protective structure, namely firstly, utilizing underwater sonar to scan and evaluate the surface flatness and the compactness of the rubble to ensure that the height difference of a stone block layer is less than 15 cm and the void ratio of a reverse filtering layer reaches the standard, secondly, testing the anchoring force of a vertical reinforced steel pile through a drawing test, and requiring the pulling strength to be not less than 1.5 times of a design value; 7) The full life cycle monitoring system is built by arranging a flow velocity sensor, a strain gauge and a corrosion monitoring probe around the pile foundation, collecting data in real time and transmitting the data to a central control platform, checking whether the surface of the protective layer is subjected to riprap displacement, crack or concrete spalling by divers every quarter, carrying out comprehensive detection once a year, including the corrosion rate of pile foundation of pile group, the permeability coefficient of a reverse filtering layer and the grading integrity of a blockbed, and simultaneously cleaning marine organism attachments on the surface of the protective structure periodically to avoid extra load and corrosion acceleration.
7. The construction method of the pile group protection structure of the water transmission line according to claim 6, wherein the inverted filter layer is composed of graded ripraps, the grain size of the graded ripraps adopted by the inverted filter layer is determined according to the travelling flow rate in extreme water flow data and the pile form factor of a pile foundation, the construction method comprises a first grain size threshold determined by the pile form factor, the riprap specific gravity and the travelling flow rate, and a second grain size threshold determined by the travelling flow rate, the riprap specific gravity and the block stone stability coefficient, and the riprap grain size of the inverted filter layer takes the smaller value of the first grain size threshold and the second grain size threshold; The stone layer has a stone particle size larger than the first particle size threshold and the second particle size threshold, and the thickness of the stone layer is larger than that of other areas in the permanent protection area and the guard area.
8. The construction method of the water transmission line pile group protection structure according to claim 7, comprising: The first particle size threshold is equal to a first correlation value divided by a second correlation value, wherein the first correlation value is a square value of a product of a travelling flow rate and a pile form factor multiplied by a constant 0.692, and the second correlation value is a value of a riprap proportion minus one multiplied by a constant 2 multiplied by a gravity acceleration, namely: ; The second particle size threshold value is equal to a third correlation value divided by a fourth correlation value, the third correlation value is a square value of a travelling flow velocity, and the fourth correlation value is a value obtained by multiplying a block stone stability coefficient by 2 times of gravitational acceleration and then multiplying a polished stone specific gravity by minus one, namely: ; Wherein, the The method comprises the steps of stone throwing particle size, V travelling flow rate, K pile form factor, S s , stone throwing specific gravity and g, and gravitational acceleration; the motion stability coefficient of the stone block; A riprap particle size for the reversed or lump-stone layer is determined based on the first and second particle size thresholds.
9. The construction method of the pile group protection structure of the water transmission line according to claim 6, wherein if the sediment start flow rate in the collected extreme water flow data is greater than the flow rate of water in the surrounding environment, the numerical values of the grain diameters of the reverse filtering layer and the throwing stone layer are unchanged, and if the sediment start flow rate is less than the flow rate of water in the surrounding environment, the numerical values of the grain diameters of the reverse filtering layer and the throwing stone layer are increased by 0.05 times of the original grain diameter values, and the sediment start flow rate is calculated through a sediment start flow rate formula so as to determine that the throwing stone cannot be started under the worst water flow condition; ; Wherein u c is the starting flow rate of sediment, and h is the water depth.
10. The construction method of the pile group protection structure for the water power transmission line according to claim 6, wherein in the construction process, when the flow rate of the water flow collected by the flow rate sensor exceeds a design threshold value, the inverted filter layer is switched to a stone throwing material with larger grain size, and the thickness of the inverted filter layer is adjusted to be three times of the larger grain size value.

Description

Protective structure of water power transmission line group pile and construction method thereof Technical Field The invention relates to the technical field of pile group protection structures, in particular to a protection structure for a pile group of a water power transmission line and a construction method thereof. Background The interference of the tower foundation pile in the water of the power transmission line on the water flow causes the local scouring of the water flow on the bed surface of the river bed around the pile foundation, and the scouring not only can cause the water destruction of the tower foundation, but also can endanger the safety of upstream and downstream buildings and nearby embankments. The water damage of the tower foundation in the water of the transmission line caused by local flushing has sudden and disastrous effects, and often causes great loss to life and property of people. In recent years, due to rapid development of power transmission line construction, more and more involved power transmission lines are successfully constructed, and scouring of pile foundations of pole towers in water under the action of complex hydrodynamic force is a troublesome problem faced by line designers and operation and maintenance personnel. In the field of pile foundation protection of offshore structures, the design and construction of a rubble protection structure are key technologies for preventing structural instability caused by flushing of pile gene water flow. In the prior art, as shown in the patent number 2024113736337, the design method, the device and the equipment of the offshore structure pile foundation riprap protection structure are named, the method mainly determines the grain diameter of the riprap, the number of protection layers and the structure size by calculating parameters such as the cutting stress of a bed surface, the diameter of the pile foundation and the scouring depth, and optimizes the protection scheme based on a mathematical model. The method mainly depends on particle size selection and layer number adjustment of the riprap material, and a composite protection system is formed without combining other materials. For example, when the riprap layer is in direct contact with the seabed, the sediment in the bottom layer may gradually run off due to osmosis, and the prior art solutions do not provide effective counter-filtration or isolation measures. In addition, the single stone throwing structure has poor adaptability when facing to the combination of silt with different particle diameters or complex wave flows, and is difficult to dynamically adjust to cope with changeable environments. Disclosure of Invention The invention aims to improve the anti-slip and anti-capsizing capabilities of the protective structure through the multidimensional anchoring of the rigid bearing platform structure and the vertical pile group, and the design can obviously improve the stability of the underwater power transmission pile group tower foundation under complex loads such as extreme waves, tide circulation and the like and prolong the service life. The invention further aims to adapt to the deposition environment of sediment with different particle sizes and effectively disperse the impact energy of water flow through the physical characteristic complementation of the multilayer materials, thereby remarkably improving the adaptability of the protective structure in changeable ocean environments. The pile group protection structure for the water power transmission line comprises a protection layer arranged on a river bed, pile group piles penetrate through the protection layer and penetrate into the river bed, the tops of the pile group piles are rigid bearing platforms, the protection layer, the pile group piles and the river bed are stacked along the vertical direction, the protection layer is arranged between the pile group piles and the river bed, the protection layer comprises a bagged sand layer, a reverse filtering layer and a block stone layer which are sequentially paved on the pretreated river bed from bottom to top, and the protection layer is divided into a primary-core area, a secondary-permanent protection area and a tertiary-protection area according to the protection importance degree. Preferably, the primary-core area is the area which is most easily washed out by the pile foundation and has the range of 1 time of single pile diameter outside the pile foundation, the secondary-permanent protection area is the area which is easily washed out by the river bed and has the range of 3 times of single pile diameter outside the pile foundation, the tertiary-protection area is the area which further improves the stability of the riprap structure, and the impact of water flow on the riprap is reduced by setting a slope angle, and the secondary-permanent protection area is the area outside the core area and the permanent protection area of the integral riprap layer