WO2022095494A1

WO2022095494A1 - Dry desilting method for riverway

Info

Publication number: WO2022095494A1
Application number: PCT/CN2021/104828
Authority: WO
Inventors: 周江; 付立宏; 朱成武; 王婧馨; 辛颖; 李备; 刘千孺; 陈守伟; 赵德岁; 许磊
Original assignee: 中铁四局集团有限公司
Priority date: 2021-06-18
Filing date: 2021-07-06
Publication date: 2022-05-12
Also published as: LU503303A1; CN113250266A; LU503303B1

Abstract

A dry desilting method for a riverway. In a working process, a river channel must be locally cut off, to allow both banks to have a certain amount of space and facilitate riverway desilting. Furthermore, riverway desilting is thorough, desilting depth is easy to control, sludge concentration is high, transportation costs are low, and engineering costs are relatively low. In the overall process, river channel desilting is carried out in segments, early-stage preparation and later-stage working is carried out at the same time, and the working process is efficient and rapid, thus both ensuring the smoothness of the river channel desilting project, and ensuring that impact on the surroundings is reduced to a minimum.

Description

River dry dredging method

technical field

The present application relates to the technical field of river dredging treatment, in particular to a dry dredging method for river courses.

Background technique

As the carrier of water resources transportation, river channels cause soil migration, deposition, and deposition of other impurities such as algae contained in the water due to the scouring of running water in the long-term transportation process, resulting in river siltation. The continuous accumulation of silt will lead to the rise of the river bed, making it difficult to transport water resources, and also affect the normal performance of various functions such as flood control, drainage, irrigation, water supply, and navigation. stinks. In order to restore the normal function of the river and promote the rapid economic and social development, it is necessary to dredging the silt deposited on the river bottom.

Therefore, it is necessary to provide an improved technical solution for the deficiencies of the above-mentioned prior art.

SUMMARY OF THE INVENTION

The purpose of the present application is to provide a dry dredging method for river courses to solve or alleviate the above-mentioned problems in the prior art.

In order to achieve the above purpose, the application provides the following technical solutions:

The present application provides a dry dredging method for a river channel, including: step S101, positioning and setting out, and measuring the elevation: setting out the construction area and the construction red line according to the construction design, and determining the construction scope; measuring the water surface elevation of the river Line, calculate the size of the water volume in sections; re-measure the elevation of the silt roof in the river channel to determine the amount of dredging in sections; step S102, clearing and leveling the site: according to the planning red line and the blue line of greening construction, clear the surface and grind the site. Flattening to a preset standard compaction degree; Step S103, site hardening, temporary access road construction: use concrete to harden the empty site and roads, and bury drainage pipes; Step S104, cofferdam construction: according to the length of the river, the cofferdam positions are carried out on both banks Stake out, start from the shore, close in one direction, fill in layers, and roll in layers; step S105, pumping: according to the water surface and the elevation of the river bottom, calculate the total pumping volume, and pump the water into the downstream reaches; step S106. Sludge excavation and outbound transportation: each section excavates a longitudinal drainage ditch on both sides of the outer side of the river silt, so that the accumulated water returns to the tank and the water pump pumps water; Solids are excavated, loaded and shipped out.

Beneficial effects:

In the river channel dry dredging method provided by the present application, before construction, the construction area and the construction red line are first set out according to the construction design, and the construction scope is determined; Re-measure the elevation of the silt roof in the river channel, determine the amount of dredging in sections, and realize the pre-construction positioning and setting out, and the preparations for the elevation measurement; during the construction process, according to the planning red line and greening construction blue line, the site is cleared. , After rolling and leveling to the preset standard compaction degree, use concrete to harden the empty site and road to realize the surface cleaning, leveling and hardening of the site, and prepare for the construction of the cofferdam and dredging; then, according to the river site, the The location of the cofferdam is staked out on both sides of the river, starting from the bank, closing the individual items, filling in layers, and rolling in layers to complete the cofferdam construction; Enter the downstream reaches of the river to dredging the bottom of the river bed; finally, excavate the silt in sections and stack it on the river bank for drying, until the silt is dried to solid, and then excavate, load, and transport to achieve complete dredging of the river. In the whole process, the river dredging is carried out in sections, and the preliminary preparation and the later construction are carried out at the same time. The construction process is efficient and fast, which not only ensures the smoothness of the river dredging project, but also ensures that the impact on the surrounding area is minimized.

During the construction of the dry dredging method of the river channel, the river channel is divided into sections and the cofferdam is built, and then the water in the river bank within the cofferdam is drained by the pump. After the water is drained, the dredging construction is carried out. According to the site conditions of the construction site, dredging is carried out along both sides of the river by means of long-arm excavator or manual excavation.

The dry dredging method of the river channel is adopted. On the one hand, during the construction process, the river channel needs to be partially cut off, which is suitable for the dredging of the river channel with a certain space on both sides and easy to cut off construction; on the other hand, the river dredging is thorough and easy to control. The dredging depth, the sludge concentration is high, and the transportation cost is low, so the engineering cost is relatively low.

Description of drawings

Fig. 1 is the schematic flow sheet of the river course dry dredging method;

Figure 2 is a schematic cross-sectional view of the cofferdam.

Detailed ways

Fig. 1 is a schematic flow diagram of a dry dredging method for a river channel provided according to some embodiments of the present application; as shown in Fig. 1 , the dry dredging method for a river channel includes:

Step S101, positioning and setting out, measuring the elevation: setting out the construction area and the construction red line according to the construction design, and determining the construction scope; measuring and setting out the water surface elevation of the river channel, and calculating the size of the water volume; Re-test to determine the amount of dredging in stages;

According to the pre-determined coordinates and elevation, the site network is established to ensure accurate elevation and location. Specifically, according to the coordinates and elevations provided by the construction design, GPS and RTK are used to establish on-site control outlets to ensure accurate elevation and location. Further, a plane and elevation control system is established on-site to perform measurement control during the entire construction period.

Among them, in the plane control system, the traverse measurement method is used to establish the plane control system, GPS, RTK and steel ruler are used to measure the line, and the straight line control pile is set. Here, the position of the control pile should be stable and reliable for easy protection during construction and convenient application. In the elevation control system, the surveying instrument adopts GPS and RTK. According to the benchmarking point provided by the user, the elevation is led to each temporary benchmarking point. The temporary benchmarking point must be firm and stable. Close the retest with the design benchmark.

Step S102, site clearing and leveling: according to the planning red line and the greening construction blue line, clearing the site, rolling and leveling it to a preset standard compaction degree; specifically, the preset standard compaction degree is not less than 90%.

In the embodiment of this application, according to the planning red line and the greening construction blue line, in order not to impress the later greening construction, the site is cleared to the red line as a temporary construction access road and fence installation site; for the section without slope protection structure, shrubs and construction waste , through the excavation equipment (such as: excavator) to directly excavate the surface, transplant or cut down the green plants, and improve the construction efficiency. The surface-clearing garbage is piled up at fixed points, and then transported to the dumping site by muck trucks. The demolished slope protection structure mortar masonry and construction waste are piled up for road construction.

Step S103, site hardening, temporary access road construction: concrete hardening is used for the empty site and road, and drainage pipes are buried, wherein the hardened road slopes toward the river, and the slope is 2%; The thickness is 25 cm, and a PC drain pipe with a diameter of 150 mm is buried every 20 meters.

A construction access road is built 1 meter outside the river green belt and hardened. Among them, the hardened road is 4.5 meters wide and 240 meters long, and some of the hardened access roads are selected as the safety experience area, and a drainage ditch is set outside the safety experience area to connect the river.

Step S104, cofferdam construction: stake out the cofferdam position on both banks according to the length of the river channel, start from the bank, close the individual items, fill in layers, and roll in layers; wherein, the slope of the cofferdam upstream side slope is 1: 2; The slope of the backwater surface of the cofferdam is 1:1.5;

Figure 2 is a schematic cross-sectional view of the cofferdam provided by the application; as shown in Figure 2, the cofferdam filling material is mainly clay, the top of the cofferdam is 3 meters wide, and the top surface of the cofferdam is 50 cm higher than the water surface of the river. The slope on the upstream side of the cofferdam is smaller than that on the downstream side of the cofferdam, which can better achieve the water blocking effect of the cofferdam. During the cofferdam filling process, the water outlet surface shall follow the principle of layered filling and layered rolling, and the compaction degree shall not be lower than 90%. In this way, the construction effect of the cofferdam can be fully guaranteed and the construction safety of the cofferdam can be improved.

Step S105, pumping: according to the water surface and river bottom elevation, calculate the total pumping volume, and pump the water circle into the downstream reaches; specifically, determine the number and model of the pumping pumps according to the calculated pumping volume.

For each section, the water surface and river bottom elevations were measured, and the total pumped volume was calculated. Since the elevation of each section is different, the calculation is carried out in combination with the longitudinal section, the transverse section and the plan view. Select the number and model of the water pump according to the volume of the river water (for example: 150m ³ /h, 1500w), and perform temporary power distribution of the generator according to the selected model of the water pump.

Due to the small electricity consumption in the construction site, the short period of time for large-scale electricity consumption (the water pumping consumes a large amount of electricity), and the construction line is long, a temporary generator is used for power supply. Moreover, since the water consumption in the early stage of the site is relatively small, and the water consumption is mostly used for river bank restoration and greening in the later stage, there is no need to introduce municipal water in the dredging section of the river.

Step S106, silt excavation and outbound transportation: excavate a longitudinal drainage ditch on each side of the outer side of the river silt in each section, so that the accumulated water returns to the tank, and the water pump pumps water; To solid, carry out excavation, loading and transportation; among them, the bottom of the river bed is leveled according to preset requirements after dredging.

The width of the drainage ditches excavated on both sides of the river silt in each subsection is 1 meter wide and 0.5 meters deep, so that the accumulated water in the river channel can be returned to the trough, and all the accumulated water can be pumped out by the water pump.

When excavating the silt, use segmented excavation. First, build the upper and lower passages of the excavation equipment on the river bank. The slope of the passage is not greater than 1:3. The mechanical construction on the silt uses steel plate bottom protection to prevent the excavation machinery from sinking into the silt. Every time you move forward, the road is paved in advance. The bottom of the river bed shall be leveled as required after the dredging is completed.

The silt is excavated to the river bank for stacking and drying, and the stacking height is not more than 1.5 meters, so as to prevent the silt from flowing into the river again. When the sludge is dried to solid, it will be excavated and loaded into trucks for transportation. During the transportation process, measures shall be taken to prevent the occurrence of "drops, spills, leaks" and other phenomena; the transportation vehicles shall travel according to the designated route during the process of inward and outward transportation.

Build cofferdams in the river, and carry out construction in sections, drain all the water in the cofferdam section, and then remove the silt at the bottom of the river with excavators. Wasteland. In the whole process, the river dredging is carried out in stages, the preliminary preparation and the later construction are carried out at the same time, and the construction process is efficient and fast.

Before construction, first set out the construction area and construction red line according to the construction design to determine the construction scope; measure and set out the water surface elevation of the river channel to calculate the size of the water volume; re-measure the elevation of the silt roof in the channel to determine the subsection During the construction process, according to the planning red line and green construction blue line, the site is cleared, rolled and leveled to the preset standard compaction degree Then, use concrete to harden the empty site and road to realize the surface cleaning, leveling and hardening of the site, so as to prepare for the construction of the cofferdam and dredging; At the beginning, the single items are closed, filled in layers, and rolled in layers to complete the construction of the cofferdam; then, the water blocking operation on the upstream surface of the cofferdam is pumped, and it is pumped into the downstream river section for dredging the bottom of the river bed. ; Finally, excavate the silt in sections and stack it on the river bank for drying, until the silt is dried to solid, and then excavate, load, and transport to achieve complete dredging of the river. In the whole process, the river dredging is carried out in sections, and the preliminary preparation and the later construction are carried out at the same time. The construction process is efficient and fast, which not only ensures the smoothness of the river dredging project, but also ensures that the impact on the surrounding area is minimized.

During construction, the river channel is divided into sections and cofferdams are built, and then the water in the river banks within the cofferdam is drained by pumps. After the water is drained, the dredging construction is carried out. According to the construction site conditions, long-arm excavators or manual excavation are often used to dredging along both sides of the river.

The dry dredging construction method of the river channel, on the one hand, during the construction process, it is necessary to partially cut off the river channel, which is suitable for the dredging of the river channel with a certain space on both sides and easy to cut off construction; on the other hand, the river dredging is thorough and easy to control. The dredging depth, the sludge concentration is high, and the transportation cost is low, so the engineering cost is relatively low.

Claims

A dry dredging method for a river course, comprising:

Step S101, positioning and setting out, measuring the elevation: setting out the construction area and the construction red line according to the construction design, and determining the construction scope; measuring and setting out the water surface elevation of the river channel, and calculating the size of the water volume; Re-test to determine the amount of dredging in stages;

Step S102, clearing and leveling the site: according to the planning red line and the greening construction blue line, clearing the site, rolling and leveling it to a preset standard compaction degree;

Step S103, site hardening, temporary access road construction: use concrete to harden the empty site and road, and bury the drainage pipe, wherein the hardened road slopes toward the river, and the slope is 2%;

Step S104, cofferdam construction: stake out the position of the cofferdam on both banks according to the length of the river channel, start from the bank, close in one direction, fill in layers, and roll in layers; wherein, the slope of the cofferdam upstream side slope is 1 : 2; the slope of the backwater surface of the cofferdam is 1:1.5;

Step S105, pumping water: calculating the total pumping volume according to the water surface and the elevation of the river bottom, and pumping the water into the downstream reaches;

Step S106, silt excavation and outbound transportation: excavate a longitudinal drainage ditch on each side of the outer side of the river silt in each section, so that the accumulated water returns to the tank, and the water pump pumps water; To solid, carry out excavation, loading and transportation; among them, the bottom of the river bed is leveled according to preset requirements after dredging.
The dry dredging method for a river channel according to claim 1, characterized in that, in step S101, an on-site network point is established according to predetermined coordinates and elevations to ensure accurate elevation and location.
The method for dry dredging of a river channel according to claim 1, characterized in that, in step S101, a plane control system is established by using a wire measurement method, and GPS, RTK and steel ruler are used to measure and pay out the line.
The dry dredging method for a river channel according to claim 1, wherein in step S102, the preset standard compaction degree is not less than 90%.
The method for dry dredging of a river channel according to claim 1, characterized in that, in step S103, C15 concrete is used to harden the empty site and road, the thickness of the road is 25 cm, and every 30 meters is buried with a diameter of 150mm PC drain.
The method for dry dredging of a river course according to claim 1, wherein in step S104, the cofferdam filling material is clay soil, the top of the cofferdam is 3 meters wide, and the top surface of the cofferdam is 50 cm higher than the water surface of the river.
The dry dredging method for a river channel according to claim 1, characterized in that, in step S105, the quantity and model of the pumping water pumps are determined according to the calculated pumping volume.
The dry dredging method for a river channel according to claim 1, wherein in step S106, the width of the drainage ditch is 1 meter and the depth is 0.5 meters.
The method for dry dredging of a river channel according to claim 1, wherein in step S106, before the silt is excavated in sections, an excavation equipment channel with a slope of not more than 1:3 is built along the bank of the river channel, and Use steel plate bottom protection.
The dry dredging method for a river channel according to any one of claims 1-9, characterized in that, in step S106, the stacking height of silt on the river bank is not greater than 1.5 meters.