LU503303B1

LU503303B1 - Method of dry-type desilting for river course

Info

Publication number: LU503303B1
Application number: LU503303A
Authority: LU
Inventors: Desui Zhao; Shouwei Chen; Lei Xu; Jingxin Wang; Lihong Fu; Bei Li; Jiang Zhou; Qianru Liu; Chengwu Zhu; Ying Xin
Original assignee: China Railway No 4 Group Co Ltd
Priority date: 2021-06-18
Filing date: 2021-07-06
Publication date: 2023-05-12
Also published as: LU503303A1; CN113250266A; WO2022095494A1

Abstract

The present application provides a method of dry type desilting for a river course, the river course needs to be set off partially during construction, which is suitable for the river course desilting with a certain space on both banks and convenient for set off construction; furthermore, the river bank is thoroughly desilted, it is easy to control the desilting depth, coupled with high sludge concentration and low transportation cost, so the engineering cost is relatively low. In the whole process, the river desilting is carried out in sections, the preliminary preparation and 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 desilting engineering, but also ensures the minimal impact on the surrounding area.

Description

BL-5606 1

LU503303

METHOD OF DRY-TYPE DESILTING FOR RIVER COURSE

BACKGROUND Field of Invention

The present application relates to the technical field of river course desilting treatment, in particular relates to a method of dry-type desilting for a river course.

Background of the Invention

As a carrier of water resources transportation, river course sedimentation is caused by soil migration and sedimentation due to the erosion of water in the long-term transportation process, as well as the deposition of algae and other impurities contained in the water. The continuous accumulation of sludge will not only lead to the rise of the riverbed, resulting in the transport difficulty of water resource, but also influencing the normal performance of each item function such as flood control, drainage, irrigation, water supply, navigation, and the continuous increase of pollutant in the river course, influencing quality of water blacking and becoming smelly. In order to restore the normal functions of the river course and promote the rapid development of the economic society, the sludge deposited on the river bottom needs to be desilted.

Therefore, it is necessary to provide an improved technical solution

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LU503303 for the above-mentioned shortcomings of the prior art.

SUMMARY

The purpose of the present application is to provide a method of dry- type desilting for a river course, in order to solve or alleviate the problems existing in the prior art.

In order to achieve the above purpose, the present application provides the following technical solutions: the present application provides a method of dry-type desilting for a river course, comprising: step S101, positioning, paying off and measuring elevation: paying off a construction area and a construction red line according to construction design to determine a construction scope; a water level of the river course is measured and paid off to calculate a sectional water volume, the top elevation of the sludge in the river course is carried out repetition measurement to determine a sectional desilting volume; step S102, site surface cleaning and leveling: the site is subjected to surface cleaning, rolling and leveling to a preset standard compaction degree according to a planned red line and a greening construction blue line; step S103,site hardening and temporary access road construction: concrete hardening 1s adopted for an empty site and a road and burying a drainage pipe; step 104, cofferdam construction:

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LU503303 setting out the cofferdam positions on both banks according to a length of the river course, starting from a bank, closing in a single direction, filling in layers and rolling in layers; step 105, pumping: calculating a total pumping volume according to the elevation of the water level and a bottom of the river, and pumping water into a lower reach; step S106, sludge excavation and outward transportation: excavating a longitudinal drainage ditch on both sides outside the river sludge in each section to enable accumulated water to return to a channel, and pumping water by a pump; excavating sludge to a bank in sections, stacking and airing until the sludge is aired to be solid, and excavating, loading, and transporting the sludge outside;.

Beneficial effects

In the method of dry-type desilting for a river course provided in the present application, before construction, firstly, paying off the construction area and the construction red line according to the construction design to determine the construction scope; the water level of the river course 1s measured and paid off to calculate the sectional water volume; the top elevation of the sludge in the river course is carried out repetition measurement to determine the sectional desilting volume, so as to realize the preparation work of positioning and paying off and measuring the elevation before construction; during construction, the site 1s subjected to surface cleaning, rolling and leveling to the preset

BL-5606 4

LU503303 standard compaction degree according to the planned red line and the greening construction blue line, concrete hardening 1s used for the empty site and the road to realize surface cleaning, leveling and hardening of site, so as to prepare for cofferdam construction and desilting; then, setting out the cofferdam positions on both banks according to the length of the river course, starting from a bank, closing in a single direction, filling in layers and rolling in layers to complete the cofferdam construction; furthermore, pumping water for blocking water on the upstream surface of the cofferdam, and pumping water into a downstream river reach so as to desilt the bottom of the river bed; finally, excavating sludge to a bank in sections, stacking and airing until the sludge is aired to be solid, and excavating, loading, and transporting the sludge outside to complete desilting work of the river course. In the whole process, the river desilting is carried out in sections, and the preliminary preparation and 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 desilting engineering, but also ensures the minimal impact on the surrounding area.

The method of dry-type desilting for a river course comprises the steps of segmenting the river course and building a cofferdam during construction, the accumulated water in the river bank within the cofferdam is drained by a pump, desilting construction is carried out after

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LU503303 draining, which is generally carried out along both banks of the river course by using a long-arm excavator excavation or manual excavation according to the site conditions of the construction site.

By adopting the dry-type desilting method for a river course, on one hand, the river course needs to be set off partially during construction, which is suitable for the river course desilting with a certain space on both banks and convenient for set off construction; on the other hand, the river bank is thoroughly desilted, it 1s easy to control the desilting depth, coupled with high sludge concentration and low transportation cost, so the engineering cost is relatively low.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a flow diagram of a method of dry-type desilting for a river course;

Fig. 2 1s a schematic diagram of cofferdam section.

DETAILED DESCRIPTION OF THE PREFERRED

EMBODYMENTS

Fig. 1 is a flow diagram of a method of dry-type desilting for a river course according to some examples of the present application; as shown in fig. 1, the method of dry-type desilting for a river course comprises the following steps:

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LU503303 step 101, positioning, paying off and measuring elevation: paying off a construction area and a construction red line according to construction design to determine a construction scope; a water level of the river course is measured and paid off to calculate the sectional water volume, the top elevation of the sludge in the river course is carried out repetition measurement to determine the sectional desilting volume; establishing site network points according to a predetermined coordinates and elevations to ensure accuracy of the elevation and positions. Specifically, establishing a site control network point by using

GPS, RTK according to the coordinates and the elevation provided by the construction design, in order to ensure the accuracy of the elevation and positions, furthermore, establishing a horizonal and a vertical control system on site to carry out measurement control during the whole construction period.

Wherein the plane control system is established by adapting a traverse survey method in the plane control system, measuring and paying off is performed by GPS, RTK and a steel tape, a liner control pile is arranged. Hereon, the position of the control pile is stable and reliable, and the control pile is convenient to protect and apply during construction period. In the elevation control system, a measurement instrument adopts

GPS and RTK, the elevation will be led to the temporary bench mark according to the bench mark provided by users, the temporary bench

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LU503303 mark must be firm and stable, the distance shall not be more than 200 m, and they are visible from front to the back, and the temporary bench mark and the design bench mark are carried out repetition measurement and closed reduction.

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

In an example of the present application, according to the planned red line and the greening construction blue line, in order not to affect later- stage greening construction, the site is cleared to the red line as the temporary construction access road and enclosure installation site; for the section without slop protection structure and with shrubs and construction wastes, the surface is directly excavated and cleaned through excavation equipment(for example: an excavator), the green plants are transplanted or felled to improve the construction efficiency. The surface cleaning waste shall be piled up at the dumping site, and then transported to the soil bank by a muck truck. The stone masonry of the destroyed slope protection structure and construction garbage are piled up for the construction of access roads.

Step S103, site hardening and temporary access road construction:

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LU503303 concrete hardening is adopted for an empty site and a road, and burying a drainage pipe, wherein a hardened road slopes toward the river course, with a slope of 2%; specifically, an empty site and a road are hardened with concrete C15, a thickness of the road is 25 cm, and a PC drainage pipe with a diameter of 150 mm is buried every 20 m.

A construction access road is built and hardened 1 m outside a greenbelt of the river course, wherein the hardened road is 4.5 m wide and 240 m long, part of the hardened access is selected as a safety experience area, and a drainage ditch is arranged outside the safety experience area to connect with the river course.

Step S104, cofferdam construction: setting out the cofferdam positions on both banks according to a length of the river course, starting from a bank, closing in a single direction, filling in layers and rolling in layers; wherein a slope of an upstream face slope of the cofferdam is 1: 2; aslope of a downstream face slope of the cofferdam is 1: 1.5; fig. 2 1s a schematic diagram of cofferdam section provided in the present application; as shown in fig. 2, a filling material of the cofferdam 1s cohesive soil, a top width of the cofferdam is 3 m, and a top surface of the cofferdam is 50 cm higher than the water surface of the river course.

The slop of the front surface of the cofferdam is less than that of the downstream of the cofferdam, so that the water blocking effect of the cofferdam can be better realized. In the process of cofferdam filling, the

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LU503303 water outlet surface follows the principles of layered filling and layered rolling, and the compaction degree is not less than 90%. Therefore, the effect of the cofferdam construction is fully ensured and the safety of the cofferdam construction is improved.

Step S105, pumping: calculating a total pumping volume according to the elevation of the water level and a bottom of the river, and pumping water into a lower reach; specifically, determining the number and model of the water pump according to the calculated water pumping volume.

The water surface and river bottom elevation are measured for each section, and the total pumping volume is calculated. Because each section elevation is different, the calculation is carried out by combining the vertical section, the cross-section and the plane diagram. Selecting the number and the model of the pump (for example: 150m*h, 1500w) according to the volume of the river, and carrying out temporary power distribution of generator according to the selected model of the pump.

Due to the small power consumption of on-site construction, short period of large amount of power consumption (large power consumption for pumping) and the long construction line, so temporary generator is used for power supply. Moreover, due to less water consumption in the early stage of the site, and the water consumption is mostly for the restoration and greening of the bank of the river course in the later stage, so municipal water does not need to be introduced into the desilting

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LU503303 section of the river course.

Step S106, sludge excavation and outward transportation: excavating a longitudinal drainage ditch on both sides outside the river sludge in each section to enable accumulated water to return to a channel, and pumping water by a pump; excavating sludge to a bank in sections, stacking and airing until the sludge is aired to be solid, and excavating, loading, and transporting the sludge outside; wherein, leveling is carried out according to the preset requirement after the riverbed bottom is desilted.

The width and the depth of the drainage ditch excavated on both sides outside the river sludge tn each section are | m and O5 m, which 1s convemient for the accumulated water in the river course to return fo the groove, and all accumulated water 1s pumped by a pump.

Sectional excavation is adopted when the sludge 18 excavated, an upper channel and a lower channel of excavation equipment are built along the bank of the river course, the slop of the channels is not more than 1:3, a steel plate bottom 1s adopted for mechanical construction on the sludge to prevent the excavation machinery from sinking into the sludge, and a road is paved in advance when the excavation machinery advances by one section. And leveling the river bed bottom according to requirements after desilting ts finshed.

The sludge is excavated to the river bank for stacking and airing, and

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LU503303 the stacking height of sludge on the bank is not more than 1.5 m, so that the sludge is prevented from flowing into the river course again. And when the sludge is aired to be solid, excavating, loading and transporting the sludge outside. During the transportation, measures are taken to prevent the phenomena such as dripping, scattering, and leakage; the carrier runs according to a designated route in the process of internal and external transportation.

The river course 1s coffered and the construction is carried out in sections, the accumulated water in the river course in the cofferdam section is completely drained, then the sludge at the bottom of the river course is removed by an excavator, the sludge is temporarily stacked to the bank, and the muck truck is used for external transportation to a spoil ground after being aired for 5-7 days. During the whole process, the river course desilting is carried out in sections, and the preliminary preparation and later construction are carried out at the same time, and the construction progress is efficient and fast.

Before construction, firstly, paying off the construction area and the construction red line according to the construction design to determine the construction scope; the water level of the river course is measured and paid off to calculate the sectional water volume; the top elevation of the sludge in the river course is carried out repletion measurement to determine the sectional desilting volume, so as to realize the preparation

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LU503303 work of positioning and paying off and measuring the elevation before construction; the site is subjected to surface cleaning, rolling and leveling to a preset standard compaction degree, concrete hardening 1s adopted for the empty site and the road to realize surface cleaning, leveling and hardening of site, so as to prepare for cofferdam construction and desilting; then, setting out the cofferdam positions on both banks according to the length of the river course, starting from a bank, closing in a single direction, filling in layers and rolling in layers to complete the cofferdam construction; furthermore, pumping water for blocking water on the front surface of the cofferdam, and pumping water into the lower reach so as to desilt the bottom of the river bed; finally, excavating sludge to a bank in sections, stacking and airing until the sludge is aired to be solid, and excavating, loading, and transporting the sludge outside to complete desilting work of the river course. In the whole process, the river desilting is carried out in sections, and the preliminary preparation and 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 desilting engineering, but also ensures the minimal impact on the surrounding area.

The method of dry type desilting for a river course comprises the steps of segmenting the river course and building a cofferdam during construction, the accumulated water in the river bank within the

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LU503303 cofferdam is drained by a pump, desilting construction is carried out after draining, wherein desilting is often carried out along both banks of the river course by using a long-arm excavator excavation or manual excavation according to the site conditions of the construction site.

By adopting the dry-type dredging method for a river course, on one hand, the river course needs to be set off partially during construction, which is suitable for the river course desilting with a certain space on both banks and convenient for set off construction; on the other hand, the river bank 1s thoroughly desilted, it is easy to control the desilting depth, coupled with high sludge concentration and low transportation cost, so the engineering cost is relatively low.

Claims

BL-5606 14 LU503303 CLAIMS

1. A method of dry type desilting for a river course, characterized by comprising: step S101, positioning, paying off and measuring elevation: paying off a construction area and a construction red line according to construction design to determine a construction scope; a water level of the river course is measured and paid off to calculate a sectional water volume; the top elevation of the sludge in the river course is carried out repetition measurement to determine a sectional desilting volume; step S102, site surface cleaning and leveling: the site 1s subjected to surface cleaning, rolling and leveling to a preset standard compaction degree according to a planned red line and a greening construction blue line; step S103, site hardening and temporary access road construction: concrete hardening is adopted for an empty site and a road, and burying a drainage pipe, wherein a hardened road slopes toward the river course, with a slope of 2%; step 104, cofferdam construction: setting out the cofferdam positions on both banks according to a length of the river course, starting from a bank, closing in a single direction, filling in layers and rolling in layers; wherein a slope of a front upstream slope of the cofferdam is 1: 2; a slope of a downstream surface slope of the cofferdam is 1: 1.5;

BL-5606 15 LU503303 step 105, pumping: calculating a total pumping volume according to the elevation of the water level and a bottom of the river, and pumping water into a lower reach; step S106, sludge excavation and outward transportation: excavating a longitudinal drainage ditch on both sides outside the river sludge in each section to enable accumulated water to return to a channel, and pumping water by a pump; excavating sludge to a bank in sections, stacking and airing until the sludge is aired to be solid, and excavating, loading, and transporting the sludge outside; wherein leveling 1s carried out according to the preset requirement after the riverbed bottom is desilted.

2. The method of dry type desilting for a river course according to claim 1, characterized in that in step S101, establishing site points according to a predetermined coordinates and elevations to ensure accuracy of the elevation and positions.

3. The method of dry type desilting for a river course according to claim 1, characterized in that in step S101, a plane control system is established by adopting a traverse survey method, measuring and paying off is performed by GPS, RTK and a steel tape.

BL-5606 16 LU503303

4. The method of dry type desilting for a river course according to claim 1, characterized in that in step S102, the preset standard compaction degree 1s not less than 90%.

5. The method of dry type desilting for a river course according to claim 1, characterized in that in step S103, an empty site and a road are hardened with concrete C15, a thickness of the road 1s 25 cm, and a PC drainage pipe with a diameter of 150 mm 1s buried every 30 m.

6.The method of dry type desilting for a river course according to claim 1, characterized in that in step S104, a filling material of the cofferdam is cohesive soil, a top width of the cofferdam is 3 m, and a top surface of the cofferdam is 50 cm higher than the water surface of the river course.

7. The method of dry type desilting for a river course according to claim 1, characterized in that in step S105, determining the number and model of the water pump according to the calculated water pumping volume.

8. The method of dry type desilting for a river course according to claim 1, characterized in that in step S106, a width of the drainage ditch 1s

BL-5606 17 LU503303 1 m and a depth 1s 0.5 m.

9. The method of dry type desilting for a river course according to claim 1, characterized in that in step S106, an excavation equipment channel with a slop not more than 1:3 is built along the bank of the river course before excavating the sludge in sections, and a steel plate is used for protecting the bottom.

10. The method of dry type desilting for a river course according to any one of claims 1-9, characterized in that in step S106, a stacking height of sludge on the bank 1s not more than 1.5 m.

BL-5606 1 LU503303 Ansprüche

1. Trockenbaggerverfahren für Fluss, das umfasst: Schritt S101: Positionieren, Abstecken und Messen der Hôhe: Abstecken des Baubereichs und der roten Baulinie gemäß dem Bauplan und Bestimmen des Bauumfangs; Messen und Abstecken der Wasseroberflächenhôhe des Flusses und Berechnen des Wasservolumens abschnittsweise, Wiederholen der Messerung der Hôhe der Schlickoberseite im Fluss, und Bestimmen der abschnittsweisen Baggermenge; Schritt S102: Räumen und Einebnen des Geländes: Räumen und Einebnen des Geländes gemäß der roten Planungslinie und der blauen Linie für den Begriinungsbau bis auf einen voreingestellten Standardverdichtungsgrad; Schritt S103: Härten des Geländes und Bauen einer temporären Zugangsstraße: Härten von leerem Gelände und Straße mit Beton, Vergraben von Entwässerungsrohr und Härten von Flussufer der Sträße mit einer Neigung 2 %; Schritt S104: Bauen des Kofferdamms: Abstecken der Position des Kofferdamms an beiden Ufern entsprechend der Länge des Flusses, Beginnen von Ufern, Schließen in einer Richtung, Füllen in Schichten und Walzen in Schichten, wobei die Neigung des dem Wasser zugewandten Fläche des Kofferdamms 1 : 2 und die Neigung der dem Wasser abgewandten Fläche des Kofferdamms 1 : 1,5 beträgt; Schritt S105: Pumpen von Wasser: Berechnen des Gesamtpumpvolumens gemäß der Wasseroberfläche und der Höhe des Flussbodens und Pumpen des Wassers in die stromabwärtigen Abschnitte; und Schritt S106: Schlickaushub und Abtransport: Ausheben eines Längsentwässerungsgrabens an den beiden Seiten des Schlicks in jedem

BL-5606 2 LU503303 Flussabschnitt, Führen des angesammelten Wassers in den Tank und Pumpen des Wassers; Stapeln und Trocknen des ausgehobenen Schlicks, Abtransport des getrockneten Schlicks; Einebenen des Flussbodens nach der Entfernung des Schlicks gemäB den vorgegebenen Anforderungen.

2. Trockenbaggerverfahren für Fluss nach Anspruch 1, dadurch gekennzeichnet, dass in Schritt S101 ein Netzpunkt vor Ort gemäß vorbestimmten Koordinaten und Hôhen festgelegt wird, um eine genaue Hôhe und Position sicherzustellen.

3. Trockenbaggerverfahren für Fluss nach Anspruch 1, dadurch gekennzeichnet, dass in Schritt S101 ein Quermessverfahren verwendet wird, um ein Ebenensteuerungssystem einzurichten, und GPS, RTK und ein Stahllineal verwendet werden, um das Messen und Abstecken durchzufiihren.

4. Trockenbaggerverfahren für Fluss nach Anspruch 1, dadurch gekennzeichnet, dass in Schritt S102 der voreingestellte Standardverdichtungsgrad nicht niedriger als 90 % beträgt.

5. Trockenbaggerverfahren für Fluss nach Anspruch 1, dadurch gekennzeichnet, dass in Schritt S103 C15-Beton verwendet wird, um das leere Gelände und die Straße zu härten, wobei die StraBendicke 25 Zentimeter beträgt, und alle 30 Meter ein PC-Entwässerungsrohr mit 150 Millimeter eingegraben wird.

BL-5606 3 LU503303

6. Trockenbaggerverfahren für Fluss nach Anspruch 1, dadurch gekennzeichnet, dass in Schritt S104 das Kofferdamm-Füllmaterial bindiges Erdreich ist, wobei die Breite der Oberseite des Kofferdamms 3 Meter beträgt und die Oberseite des Kofferdamms 50 Zentimeter hôher ist als die Wasseroberfläche des Flusses.

7. Trockenbaggerverfahren für Fluss nach Anspruch 1, dadurch gekennzeichnet, dass in Schritt S105 die Menge und der Typ der Wasserpumpe gemäB dem berechneten Pumpvolumen bestimmt werden.

8. Trockenbaggerverfahren für Fluss nach Anspruch 1, dadurch gekennzeichnet, dass in Schritt S106 die Breite des Entwässerungsgrabens 1 Meter und die Tiefe 0,5 Meter beträgt.

9. Trockenbaggerverfahren für Fluss nach einem der Ansprüche 1 bis 8, dadurch gekennzeichnet, dass in Schritt S106 vor dem abschnittsweisen Ausheben des Schlicks entlang des Flussufers ein Kanal mit einer Neigung von hôchstens 1 : 3 errichtet wird und der Boden mit Stahlblechen geschützt wird.

10. Trockenbaggerverfahren für Fluss nach einem der Ansprüche 1 bis 9, dadurch gekennzeichnet, dass in Schritt S106 die Stapelhôhe von Schlick auf dem Flussufer nicht größer als 1,5 Meter ist.