Ecological prevention and treatment and pre-treatment method for co-ordination of emergency of slope convex slope accumulation body and landslide dam body

Abstract

This invention discloses a pretreatment method for ecological prevention and coordinated emergency response to colluvial deposits and landslide dams on riverbanks. It utilizes mature trees planted vertically at the slope toe, intersecting with horizontally planted mature trees on the slope surface to form a framework of living trees. Simultaneously, waterproof soil bags filled with rock and soil fragments are used to construct soil pillars or walls, providing support for the horizontally planted mature trees. The framework of living trees and the soil pillars or walls together form a retaining structure to prevent potential landslide impacts. The spaces between the soil pillars or walls create a drainage channel for the landslide dam, collectively providing ecological prevention and coordinated emergency response to colluvial deposits and landslide dams on riverbanks. This invention can replace the post-treatment technology of emergency excavation of spillways after landslide dam formation. By pre-constructing the drainage channel before the dam forms, it achieves ecological protection of riverbanks, reduces the risk of landslide damming, and is easy to construct.

Description

Technical Field

[0001] This invention belongs to the field of ecological protection and disaster prevention and mitigation engineering for river slopes, specifically involving methods for ecological prevention and control of colluvial deposits and collaborative emergency pre-treatment of landslide dams on river slopes. Background Technology

[0002] The loss of stability and landslide damage of riverbank slopes is a major ecological and environmental problem hindering national development and the improvement of people's economic lives. This is especially true for canyon riverbanks, where high-altitude landslides are typically sudden and rapid, sometimes leaving no time for reaction. During the sliding process, the landslide impacts the colluvial deposits protruding from the slope surface, rapidly increasing in volume due to the scraping effect and gaining extremely high kinetic energy with the help of the terrain. This can generate massive volumes of landslide earth in a short period, creating dams or even blocking the river channel. In remote riverbank engineering projects, significant investments are only made in riverbank slope protection and landslide damming when landslide deposits and damming problems occur and emergency response is necessary. Therefore, how to effectively prevent and control colluvial deposits and landslide dams on riverbanks remains a major technical and economic challenge in riverbank engineering.

[0003] While constructing protective forests at the toe of highway slopes can achieve ecological protection, in the highway transportation sector, planting is generally only permitted at the toe. In river engineering, to ensure smooth river flow, planting trees on the riverbed or even the bottom of the riverbank is generally prohibited. Currently, the country has carried out some ecological river management demonstration projects, such as riprap revetment combined with grass planting and composite revetment with timber piles and vegetation. However, these generally emphasize the concept of landscape water conservancy and cannot solve the aforementioned problems. Regarding ecological protection of river slopes and the handling of landslide dams, there is an overemphasis on emergency post-treatment techniques, such as reinforcing river slopes after a landslide and hastily excavating emergency spillways after landslide damming (post-treatment techniques). There is a lack of research and application of comprehensive ecological prevention and control technologies for protruding colluvial deposits and landslide dams on river slopes, and a lack of in-depth and effective ecological protection techniques and effective pre-treatment techniques (pre-constructing underground spillway channels at the bottom of the dam before its formation). Therefore, there is an urgent need to invent a pretreatment method for ecological prevention and coordinated emergency response to colluvial deposits and landslide dams protruding on riverbank slopes. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing conventional technologies by providing a pretreatment method for ecological prevention and coordinated emergency response of colluvial deposits and landslide dams on protruding slopes, so as to achieve ecological protection of riverbank slopes and pretreatment for ecological prevention and coordinated emergency response of landslide dams, thereby reducing the risk of riverbank slope instability loss and landslide damming.

[0005] This invention was proposed with the support of the National Natural Science Foundation of China Joint Fund Project.

[0006] The pretreatment method for ecological prevention and coordinated emergency response of landslide dams provided by this invention includes the following:

[0007] (1) Without obstructing the flow of the river, a number of straight-growing trees (trees) are planted in a row along the slope at the toe of the slope in the landslide-prone section of the riverbank to form a protective forest;

[0008] (2) For each row of trees, dig horizontal planting pits at equal intervals on the slope from the foot of the slope upwards along the slope direction. The planting pits are in the same row as each row of trees.

[0009] (3) Transplant the pre-planted fresh mature trees into each horizontal planting pit, so that they lie horizontally and extend out of the slope.

[0010] (4) For each row of vertical trees, dig pits and level them at the bottom of each tree from the foot of the slope upwards to form a base (foundation). Stack the soil bags filled with the accumulated rock and soil fragments on site to form several soil pillars or earth walls in the horizontal direction of the slope. During the process of stacking soil pillars or earth walls with soil bags, reserve holes at the same height as the vertical elevation of each horizontal planting pit. Place the horizontal trees on the soil pillars or walls, and continue to stack soil bags. Place the main trunk of the horizontal trees in the holes or top of each row of soil pillars or earth walls to obtain support.

[0011] (5) Tie the horizontal and vertical trees together with cable ties at the junction of each row of horizontal trees and vertical trees so that the vertical trees and horizontal trees intersect to form a living tree frame structure. Then, together with each row of earth pillars or earth walls, a supporting structure of tree frame shed is formed to prevent potential landslides from impacting the riverbank slope. A drainage channel for landslide dam is formed between the earth pillars or earth walls. Even if the landslide falls into the tree frame, it will form a loose slope soil accumulation, which will play the role of slope toe ballast.

[0012] Furthermore, in step (1), the row spacing and column spacing of the trees are both 2 to 3 m; preferably, the tree species are mature metasequoia or eucalyptus, etc.

[0013] Furthermore, in step (2), the vertical position difference between two adjacent transverse planting pits is 2-3m, thereby determining the distance between them along the slope.

[0014] Furthermore, the soil bag mentioned in step (4) is a prefabricated waterproof bag that has been filled with crushed rock and soil material on site and then tied up. This can solve the problem of lack of large stone materials for the use of gabions on site.

[0015] Furthermore, each soil column in step (4) is constructed by stacking multiple layers of soil bags, with two soil bags placed side by side in each layer, and the orientation of the two soil bags in the upper layer is perpendicular to the orientation of the two soil bags in the lower layer. That is, each adjacent layer is stacked with staggered joints (referring to the gaps between two soil bags placed side by side in the same layer); the soil wall can be continuously stacked in the same manner.

[0016] Furthermore, in step (4), the earth pillars or earth walls are attached to the upper side of the slope of each row of vertical trees, and each row of vertical trees acts as the wall piers of the earth pillars or earth walls, providing support.

[0017] Under the protection of the living timber frame retaining structure constructed by the method of this invention, when a landslide occurs, the living mature timber frame and soil pillars or walls at the toe of the slope act as a buffer to block the landslide body. Even if a landslide body rushes in, it will fall as loose rock and soil, making it more permeable. This allows for preferential seepage and erosion to discharge floodwaters when the landslide deposit blocks the river channel. After the landslide body accumulates, the corridors formed between each row of vertical waterproof soil pillars or walls can also serve as water passages after the potential landslide deposit becomes a dam. In this way, even if a landslide dam occurs, the pre-treatment method at the bottom of the dam, with the pre-set timber frame and underground flood discharge channel, buys time to mitigate the sudden rise in water level and to facilitate emergency rescue using traditional post-treatment methods such as digging a spillway on the top of the dam, without causing panic. Therefore, this invention is a pre-treatment method for collaborative emergency response.

[0018] Based on the same technical concept, this invention also provides a pretreatment method for ecological prevention and coordinated emergency response of colluvial deposits protruding from riverbank slopes. This method is similar to the aforementioned pretreatment method for ecological prevention and coordinated emergency response of landslide dams on riverbank slopes, except that when excavating the transverse planting pits, the excavation is done on the lower side of the colluvial deposit. Mature trees are planted horizontally on the colluvial deposit, intersecting with vertically planted mature trees on the slope to form a framework structure of living trees. This framework, together with soil pillars or walls, forms the entire retaining structure, located on the lower slope surface of the colluvial deposit, thus stabilizing the soil on the slope. In this way, relying on the support of vertical and transverse trees, each slope deposit that may be prone to sliding is stabilized, and the entrainment and expansion effect of the protruding colluvial deposits during a landslide is reduced. In this scheme, depending on the size of the colluvial deposit, single or multiple horizontally planted trees can be used.

[0019] In practical engineering, for river slopes with colluvial deposits that protrude from the slope, the two methods mentioned above are often combined to carry out coordinated ecological prevention and control of the colluvial deposits and landslide dams on the river slope.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. Because it is difficult to assess the landslide-prone sections of riverbanks through geological assessment, in remote riverbank projects, people only spend a lot of money on the protection of riverbanks and the treatment of landslide dams when landslide damming problems occur and emergency treatment is necessary. Therefore, in landslide-prone sections that are not very certain, it is difficult to persuade the funders to adopt more expensive engineering techniques for reinforcement.

[0022] The method of this invention utilizes a framework of fresh timber combined with bagged aggregate rock and soil fragments to form soil columns or walls, providing pretreatment for ecological prevention and coordinated emergency response to colluvial deposits and landslide dams on riverbank slopes. This achieves ecological protection of riverbank slopes, reduces the risk of landslides and dams, and is easy to construct, shortening the construction period and reducing costs. It achieves excellent economic, environmental, and social benefits, integrating riverbank slope protection and ecological environmental protection functions. The trees grow naturally, realizing harmonious coexistence between ecological slope protection projects and nature, and possessing ecological and sustainable characteristics.

[0023] 2. The method of the present invention utilizes the on-site accumulated rock and soil fragments to fill waterproof bags, forming waterproof bag soil columns or soil walls. The water passage between each row of soil columns or soil walls can achieve the same effect as using gabion retaining walls. Moreover, the materials are sourced locally, and the waterproof membrane bag materials are easy to transport and handle, achieving a good coupling of technicality and economy, and demonstrating good ecological benefits.

[0024] 3. The method of the present invention cleverly arranges trees and plants in a crisscross pattern near the foot of the slope when it is difficult to plant protective forests on riverbank slopes, forming a framework of living mature trees. This not only serves as an engineering protection measure, but also helps people in mountainous areas to generate economic benefits by propagating and selling trees and timber.

[0025] 4. The method described in this invention is reasonably designed, simple in process, easy to construct, convenient to operate, low in cost, easy to maintain, and easy to promote. It can be used for the pretreatment of ecological prevention and coordinated emergency response for colluvial bodies protruding from riverbank slopes and landslide dams. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a pretreatment method for ecological prevention and coordinated emergency response to colluvial deposits and landslide dams caused by a living mature forest frame combined with an earthen wall, according to an embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram of a frame structure formed by vertically growing mature trees and horizontally growing mature trees according to an embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram of a waterproof bag-soil wall supporting a horizontally growing mature tree, according to an embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram illustrating how a living, mature tree frame provides ecological protection for each protruding slope deposit according to an embodiment of the present invention.

[0030] In the diagram, 1-riverbank slope, 2-vertical mature trees, 3-horizontal planting pits, 4-waterproof bags filled with on-site rock and soil debris, 5-vertical horizontal earthen wall, 6-horizontally growing mature trees, 7-joint points of the framework of fresh mature trees, 8-underground spillway between earthen walls, 9-emergency spillway excavated for emergency treatment (post-treatment) of the landslide dam surface, 10-1 relatively dense deposits or landslide dam, 10-2 relatively loose deposits or landslide dam (due to the supporting effect of the tree framework structure), 10-3 scattered protruding deposits on the slope. Detailed Implementation

[0031] The present invention will be further illustrated below through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above-described invention, and these improvements and adjustments still fall within the scope of protection of the invention.

[0032] Example 1

[0033] The pretreatment method for ecological prevention and coordinated emergency response of colluvial deposits and landslide dams protruding on riverbank slopes provided in this embodiment includes the following steps:

[0034] (1) In the slippery section of the riverbank, without obstructing the flow of the river, several straight-growing trees (trees) are planted in rows along the slope near the foot of the riverbank to form a protective forest. The spacing between each row and each column is about 2 meters. The tree species selected are mature metasequoia or eucalyptus trees that grow straight.

[0035] (2) Along the slope direction, for each row of mature vertical trees at the foot of the slope, dig horizontal planting pits one by one on the slope of the riverbank at intervals of about 2 meters vertically. The planting pits are in the same row as each row of trees.

[0036] (3) Transplant the pre-planted fresh mature trees with soil balls to each horizontal planting pit, so that they lie horizontally and extend out of the slope;

[0037] (4) For each row of vertical trees, dig pits and level them at the bottom of each tree from the foot of the slope upwards to form a base. Stack the soil bags filled with rock and soil debris to form a transverse earth wall on the slope. During the process of stacking the earth wall with soil bags, leave holes at the same height as the vertical elevation of each transverse planting pit. Place the horizontal trees on the earth wall and continue to stack the soil bags. In this way, the horizontal trees in the same row pass through the same row of earth walls. The trunks of the horizontal trees are placed in the openings or on top of each row of earth walls for support. The soil bags are prefabricated waterproof bags that are filled with rock and soil debris and tied off on site. This can solve the problem of lack of large stone materials for using gabions on site. Each earthen wall is constructed from multiple layers of stacked earthen bags, with two bags placed side by side in each layer. The orientation of the two bags in the upper layer is perpendicular to the orientation of the two bags in the lower layer, meaning that adjacent layers are stacked with staggered joints (the gaps between two bags placed side by side in the same layer). The earthen wall is placed against the upper side of the slope of each row of vertical trees, which act as piers to support the earthen wall.

[0038] (5) At the junction of each row of horizontally lying fresh trees and the vertical trees near the foot of the slope, use cable ties to tightly connect the vertical and horizontally lying mature trees. The vertical and horizontally growing trees intersect to form a fresh tree frame structure, connecting each row of earthen walls, forming a support structure of the tree frame shed to prevent potential landslide impacts. Even if the landslide falls into the tree frame, it will form a loose slope soil accumulation, which will act as a slope foot ballast.

[0039] In this embodiment, when a landslide occurs, the viable mature timber frame and earthen walls at the toe of the slope act as a buffer to block the landslide mass. Even if a landslide mass rushes in, it will fall as loose soil and rock, making it more permeable. This allows for preferential seepage and erosion to discharge floodwaters if the landslide deposit blocks the river channel. After the landslide mass accumulates, the corridors between each row of vertical waterproof earthen walls can also serve as water passages after a potential landslide deposit dam is formed. In this way, even if a landslide dam is formed, the pre-set timber frame and underground spillway at the bottom of the dam provide time to mitigate the sudden rise in water level and to facilitate emergency rescue operations using traditional methods such as digging spillways on the top of the dam, preventing panic.

[0040] Example 2

[0041] This embodiment provides a pretreatment method for ecological prevention and coordinated emergency response to colluvial deposits protruding on riverbank slopes. The method is similar to the pretreatment method for ecological prevention and coordinated emergency response to riverbank landslide dams in Embodiment 1, except that the transverse planting pits are relocated to the lower side of the colluvial deposit. Mature trees are planted horizontally on the deposit, with the vertical and horizontal trees intersecting to form a framework of living trees. This framework, along with the earthen wall, forms the entire retaining structure, located on the lower slope of the colluvial deposit, thus reinforcing the slope deposit. In this embodiment, depending on the size of the colluvial deposit, single or multiple horizontal trees can be planted. In this way, relying on the support of the vertical and horizontal trees, each colluvial deposit that may slide or fail is stabilized.

Claims

1. A pretreatment method for ecological prevention and coordinated emergency response to landslide dams, characterized in that, Includes the following: (1) Without obstructing the flow of the river, a number of straight-growing trees are planted in rows along the slope at the toe of the landslide-prone section of the riverbank to form a protective forest; the tree species are mature metasequoia or mature eucalyptus. (2) For each row of trees, dig horizontal planting pits at equal intervals on the slope from the foot of the slope upwards along the slope direction. The planting pits are in the same row as each row of trees. (3) Transplant the pre-planted fresh mature trees into each horizontal planting pit, so that they lie horizontally and extend out of the slope. (4) For each row of vertical trees, dig pits and level them at the bottom of each tree from the foot of the slope upwards to form a base. Stack the soil bags filled with rock and soil debris on site to form several soil pillars or rows of soil walls in the horizontal direction of the slope. During the process of stacking soil pillars or soil walls with soil bags, reserve holes at the same height as the vertical elevation of each corresponding horizontal planting pit. Place the horizontal trees on the soil pillars or soil walls, and continue to stack soil bags. Place the main trunk of the horizontal trees in the holes or on top of each row of soil pillars or soil walls to obtain support. The soil column is composed of multiple layers of soil bags stacked together, with two soil bags placed side by side in each layer, and the orientation of the two soil bags in the upper layer is perpendicular to the orientation of the two soil bags in the lower layer. That is, each adjacent two layers are stacked with staggered joints, so that the gaps between the two soil bags in the adjacent two layers are perpendicular. The soil wall is stacked horizontally in the same way. The earthen pillars or earthen walls are stacked against the upper side of the slope of each row of vertical trees, and each row of vertical trees acts as the wall piers of the earthen pillars or earthen walls, thus providing support. The soil bags mentioned in step (4) are obtained by filling the waterproof bags with crushed rock and soil material on site; (5) Tie the horizontal and vertical trees together with cable ties at the junction of each row of trees, so that the vertical and horizontal trees intersect to form a living tree frame structure. Then, together with each row of earth pillars or earth walls, a supporting structure of tree frame shed cave is formed to prevent the impact of potential landslide bodies on the riverbank slope, and a drainage channel for landslide dam bodies is formed between the earth pillars or earth walls. When there are protruding colluvial deposits on the river slope, the transverse planting pits are excavated on the lower side of the colluvial deposits. Through the support structure formed by the fresh timber frame structure and the transverse soil pillars or earthen walls, the purpose is to stabilize each slope deposit that may be slipped and damaged.

2. The method according to claim 1, characterized in that, In step (1), the spacing between rows and columns of trees is 2 to 3 meters.

3. The method according to claim 1, characterized in that, In step (2), the vertical position difference between two adjacent horizontal planting pits is 2-3m, and the distance between them along the slope is determined accordingly.

4. A pretreatment method for ecological prevention and coordinated emergency response of colluvial deposits with protruding slopes, characterized in that, According to the method of claim 1, when excavating the transverse planting pit, the position of the transverse planting pit is changed to be excavated on the lower side of the protruding colluvium, and mature trees are planted horizontally on the colluvium and cross-connected with the mature trees planted vertically on the lower slope of the protruding colluvium.

5. The method according to claim 4, characterized in that, Plant one or more horizontal mature trees and one or more vertical mature trees, depending on the size of the colluvial deposits protruding from the slope.

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