Environment-friendly anti-collapse temporary bridge and construction method

Abstract

The present application relates to the technical field of temporary bridge, especially relates to an environment-friendly anti-collapse temporary bridge and a construction method, which comprises the following steps: S1, determining the riverbed construction position of the spliced bridge deck main body; S2, carrying out iron drum protection excavation and adjusting the set excavation rotating speed in real time; S3, adjusting the set excavation rotating speed or sand pumping matching coefficient according to the real-time river water turbidity and the initial river water turbidity; S4, pouring underwater concrete through the cavity in the supporting steel pipe column; and S5, using angle steel to weld two adjacent supporting steel pipe columns for transverse reinforcement. The present application avoids the collapse of the bridge deck by supporting and pulling the temporary floating bridge, realizes the integrated temporary bridge of floating, pulling and supporting, adopts the overall underwater construction scheme, reduces the construction engineering quantity, divides the construction of the single riverbed construction position, realizes intelligent coordinated construction, guarantees the construction efficiency of the temporary bridge, and reduces the influence on the river ecology of the construction area.

Description

Technical Field

[0001] This invention relates to the field of temporary bridge technology, and in particular to an environmentally friendly, anti-collapse temporary bridge and its construction method. Background Technology

[0002] Temporary bridges are erected to address obstacles posed by rivers, canyons, and ditches to construction or temporary passage. They generally consist of an upper bridge span structure and lower bridge piers. Their basic characteristics are simple structure, easy operation, short erection time, and easy repair. For the construction of temporary bridges in river areas, floating bridges are often used. To prevent bridge deck collapse and ensure stability, corresponding bridge pier supports are usually installed at the bottom of the river in the construction area. This can lead to the impact on river water quality during construction and, with the increase in construction volume, can also affect the river ecosystem.

[0003] Chinese Patent Publication No. CN111236290A discloses a simple environmentally friendly device and construction method for preventing scour of bridge pier pile foundations. It uses a funnel-shaped protective device to allow sand or water to flow into the cavity through several through holes, thereby suppressing the damage of horseshoe vortices and tail vortices to the pile foundation. It can be seen that in the existing underwater bridge construction, it is impossible to control the agitation of the riverbed sediment during construction, especially during large-scale construction, which can easily cause impacts on river water quality and ecology. Summary of the Invention

[0004] Therefore, the present invention provides an environmentally friendly anti-collapse temporary bridge and its construction method to overcome the environmental impact on the river area during the construction of anti-collapse temporary bridges in the prior art.

[0005] To achieve the above objectives, the present invention provides a construction method for an environmentally friendly, anti-collapse temporary bridge, comprising: Step S1: Assemble the various floating modules to form a flexible bridge deck body, and lay the flexible bridge deck body on the river surface at the temporary bridge river. Fix both ends of the bridge deck body to the banks of the river. Determine the number of bridge deck support points and the corresponding riverbed construction position of each support point according to the length of the bridge deck body. Step S2: Insert the sheet metal bucket into the construction location on the riverbed, and excavate the riverbed inside the sheet metal bucket using an underwater tunneling device. Calculate the tunneling resistance evaluation value based on the set tunneling speed of the underwater tunneling device and the real-time tunneling speed during tunneling, and adjust the set tunneling speed of the underwater tunneling device in real time based on the tunneling resistance evaluation value. Step S3: Control the real-time sand pumping power of the sand pumping pump according to the preset sand pumping matching coefficient and the set tunneling speed of the underwater tunneling device. The sand pumping pumps out the loose mud and sand inside the iron bucket during tunneling and discharges it to the riverbank. The real-time river water turbidity at the construction site is detected by a turbidity detector set on the outside of the iron bucket. The real-time river water turbidity and the initial river water turbidity are calculated and judged to adjust the set tunneling speed or the preset sand pumping matching coefficient of the underwater tunneling device in real time. Step S4: Insert the supporting steel pipe column into the iron bucket, so that the bottom of the supporting steel pipe column is lower than the riverbed plane. Pour the mixed underwater concrete into the pit formed in the iron bucket through the cavity inside the supporting steel pipe column. During pouring, lift the iron bucket to the preset height. After the iron bucket is lifted, pour the underwater concrete until it fills the iron bucket. After the underwater concrete solidifies, fix the supporting steel pipe column and start construction at the riverbed construction position corresponding to the next support point. Step S5: Fix each fixed supporting steel pipe column to the corresponding bridge deck support point, and use angle steel to weld it to two adjacent supporting steel pipe columns to perform lateral reinforcement of the supporting steel pipe columns, thus completing the construction of the temporary bridge.

[0006] Furthermore, in step S2, a standard resistance evaluation value is set, and the tunneling resistance evaluation value is calculated based on the set tunneling speed and the real-time tunneling speed of the underwater tunneling device. If the tunneling resistance evaluation value is less than or equal to the standard resistance evaluation value, then there is no need to adjust the set tunneling speed of the underwater tunneling device; If the tunneling resistance evaluation value is greater than the standard resistance evaluation value, the set tunneling speed of the underwater tunneling device will be adjusted in real time according to the tunneling resistance evaluation value. Wherein, Ns = (Vc - Vs) / Vc, Ns is the tunneling resistance evaluation value, Vc is the set tunneling speed, Vs is the real-time tunneling speed, Vc' = Vc - Vc × (Ns - Nb) / Nb, Vc' is the adjusted set tunneling speed, and Nb is the standard resistance evaluation value.

[0007] Furthermore, in step S2, a minimum tunneling speed of the underwater tunneling device is set. When the set tunneling speed of the underwater tunneling device is adjusted in real time according to the tunneling resistance evaluation value, the adjusted set tunneling speed is compared with the minimum tunneling speed in real time. If the adjusted set tunneling speed is less than the minimum tunneling speed, the underwater tunneling device will be stopped for inspection. If the adjusted set tunneling speed is greater than or equal to the minimum tunneling speed, the underwater tunneling device will be controlled to tunnel at the adjusted set tunneling speed.

[0008] Furthermore, in step S3, a sand dredging matching coefficient is preset. When the underwater tunneling device is tunneling the riverbed, the real-time sand dredging power is calculated based on the real-time setting of the tunneling speed of the underwater tunneling device and the sand dredging matching coefficient, and the real-time sand dredging power is used to control the sand dredging pump to extract the mud and sand inside the iron barrel. Where Ps = R × Vi, Ps is the real-time sand dredging power, R is the preset sand dredging matching coefficient, Vi is the real-time set tunneling speed of the underwater tunneling device, and Vi is equal to Vc or Vc'.

[0009] Further, in step S3, the turbidity detector is set at the upper edge of the outer side of the metal drum, and the upper edge of the metal drum is higher than the riverbed plane. The turbidity of the river water is collected as the initial turbidity of the river water before the underwater tunneling device starts tunneling into the riverbed. The real-time turbidity of the river water outside the metal drum is detected when the underwater tunneling device starts tunneling into the riverbed. The change value of the river water turbidity is calculated based on the initial turbidity and the real-time turbidity. Where Ua = Us - Uc, Ua is the change in river turbidity, Us is the real-time river turbidity, and Uc is the initial river turbidity.

[0010] Furthermore, in step S3, a first preset turbidity change value and a second preset turbidity change value are set, and the first preset turbidity change value is less than the second preset turbidity change value. When the underwater tunneling device performs tunneling construction on the riverbed, the calculated river water turbidity change value will be determined based on the first preset turbidity change value and the second preset turbidity change value. If the change in river water turbidity is less than or equal to the first preset turbidity change value, then the set tunneling speed or the preset sand dredging matching coefficient of the underwater tunneling device will not be adjusted. If the change in river water turbidity is greater than the first preset turbidity change value and less than or equal to the second preset turbidity change value, the set tunneling speed of the underwater tunneling device will be adjusted according to the change in river water turbidity and the first preset turbidity change value. Where Vi' = Vi × [1 - (Ua - U1) / U1], Ua is the change value of river water turbidity, U1 is the first preset turbidity change value, Vi is the real-time set tunneling speed of the underwater tunneling device, Vi is equal to Vc or Vc', and Vi' is the adjusted real-time set tunneling speed of the underwater tunneling device. If the change in river water turbidity is greater than the second preset turbidity change value, the detection result of the second turbidity detector will be obtained for judgment, so as to adjust the preset sand dredging matching coefficient. Further, in step S3, the second turbidity detector is positioned at the upper edge of the inner side of the tin bucket, and the real-time turbidity Ut inside the tin bucket is detected by the second turbidity detector. If the real-time turbidity in the bucket is greater than or equal to the real-time turbidity of the river water, the sand dredging matching coefficient is increased and adjusted according to the change value of the river water turbidity and the second preset turbidity change value. Where R1=R×[1+(Ua-U2) / U2], R1 is the increased and adjusted sand dredging matching coefficient, R is the preset sand dredging matching coefficient, U2 is the second preset turbidity change value, and Ua is the change value of the river water turbidity. If the real-time turbidity in the bucket is less than the real-time turbidity of the river water, the sand dredging matching coefficient is reduced and adjusted according to the change value of the river water turbidity and the second preset turbidity change value. Here, R2=R×[1+(U2-Ua) / U2], R2 is the sand dredging matching coefficient after reduction and adjustment, R is the preset sand dredging matching coefficient, U2 is the second preset turbidity change value, and Ua is the change value of the river water turbidity.

[0011] Furthermore, the metal drum is cylindrical with no lid at the top and no bottom at the bottom, and the supporting steel pipe column is a hollow tube. In step S4, the supporting steel pipe column is inserted into the internal space of the metal drum along the axis of the metal drum. The supporting steel pipe column does not contact the metal drum. The supporting steel pipe column is suspended and fixed above the river surface. The preset height to which the metal drum is lifted is not less than three-quarters of the height of the metal drum.

[0012] Furthermore, in step S4, when the metal bucket is lifted upwards, it is slowly pulled out at a fixed speed, and the fixed speed is not higher than the maximum lifting speed. Where F = Lt / 12, unit: meters / second, F is the maximum lifting speed, and Lt is the axial height of the iron drum.

[0013] The present invention also provides a temporary bridge constructed based on any of the above-mentioned environmentally friendly anti-collapse temporary bridge construction methods, comprising a flexible bridge deck body formed by splicing several floating modules and capable of floating on the river surface, several fixed piers formed by underwater concrete solidification, several supporting steel pipe columns inserted into the fixed piers and connected to the bridge deck body, and several angle steels for connecting the supporting steel pipe columns.

[0014] Compared with existing technologies, the advantages of this invention are as follows: by using a floating bridge deck, it is easier to construct temporary bridges. Furthermore, the support structure beneath the floating bridge deck significantly improves the load-bearing capacity of the temporary floating bridge, preventing collapse due to load or span. The use of metal drums to stabilize the riverbed sediment prevents the impact of river flow on the foundation pit construction. Simultaneously, the invention facilitates dredging and sand removal within the foundation pit. The dredging resistance is calculated based on the real-time dredging speed of the underwater tunneling device, and the set dredging speed is adjusted accordingly. The turbidity of the river water at the construction site is also adjusted to match the dredging efficiency of the underwater tunneling device with that of the dredging pump, reducing the impact of sediment erosion on the river environment. This method is more suitable for large-scale construction. The underwater construction method is also more convenient than traditional river diversion or damming construction, ensuring rapid construction and stability of the temporary bridge while greatly protecting the original river ecosystem.

[0015] Furthermore, by calculating the ratio of the difference between the set tunneling speed and the actual real-time tunneling speed of the underwater tunneling device, the tunneling resistance evaluation value is calculated to indirectly characterize the riverbed condition during underwater excavation. The real-time tunneling resistance evaluation value is then judged by the set standard resistance evaluation value to determine whether the current excavation state of the underwater tunneling device is within the standard state. The set tunneling speed is adjusted in real time to increase the drilling torque by increasing the drilling speed of the underwater tunneling device, thereby responding to the riverbed condition in real time and ensuring the efficiency of riverbed excavation.

[0016] Furthermore, by setting a minimum tunneling speed, the adjustment process of the underwater tunneling device is ensured to be stable, avoiding the looping of the tunneling drill bit speed adjustment mode due to self-adjustment, which would result in unlimited speed reduction, leading not only to extremely low tunneling efficiency but also affecting the overall construction progress of the temporary bridge.

[0017] In particular, by setting a sand dredging matching coefficient, the sand dredging efficiency of the sand pump can be matched with the drilling efficiency of the underwater tunneling device in real time. This avoids the overflow of mud and sand from the underwater tunneling device into the metal bucket due to low sand dredging efficiency, while also preventing the rapid pumping of river water from the metal bucket due to high sand dredging efficiency, which would cause the river water outside the bucket to fill into the bucket and stir up the bottom of the riverbed outside the bucket. Therefore, real-time matching of the operating status of the underwater tunneling device and the sand pump can reduce the impact on the original river ecological environment during the construction of temporary bridges.

[0018] In particular, by calculating the turbidity of the river water outside the metal bucket inserted into the riverbed, the underwater tunneling status can be determined in real time. When the change in river water turbidity is less than or equal to the first preset turbidity change value, it indicates that the construction process inside the bucket has little impact on the river water, so no adjustment is made to the construction. When the change in river water turbidity is between the first and second preset turbidity change values, it indicates that the construction process inside the bucket has already had a certain impact on the environment outside the bucket. Therefore, the construction workload can be reduced by decreasing the rotation speed of the underwater tunneling device, ensuring the stability of the river water in the construction area, and reducing the impact on the river environment.

[0019] Furthermore, when the change in river water turbidity exceeds the second preset turbidity change value, it indicates that the construction matching inside the bucket is severely unbalanced. Therefore, by comparing the turbidity inside and outside the iron bucket, the main impact of this turbidity change is determined. If the real-time turbidity inside the bucket is greater than or equal to the real-time river water turbidity, it indicates that the real-time sand dredging efficiency is low, and the silt inside the bucket cannot be discharged in time, resulting in silt overflow. If the real-time turbidity inside the bucket is less than the real-time river water turbidity, it indicates that the rapid emptying of the river water inside the bucket causes river water replenishment, affecting the water flow and agitation of the riverbed outside the bucket. Therefore, the sand dredging matching coefficient is adjusted accordingly to accurately control the sand dredging efficiency and reduce the impact of construction on the river environment.

[0020] Furthermore, by injecting underwater concrete into the supporting steel pipe columns, the underwater concrete can be accurately deposited in the foundation pit. By lifting the iron bucket containing the underwater concrete, the underwater concrete, which has a higher density than the sediment at the bottom of the riverbed, is compressed into the surrounding riverbed. At the same time, the lower density river water is squeezed out to form a more stable underwater temporary bridge pier, which further improves the stability of the temporary bridge. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating the construction method of the environmentally friendly, collapse-resistant temporary bridge in this embodiment; Figure 2 This is a schematic diagram of the riverbed excavation and sand dredging construction in this embodiment; Figure 3 This is a schematic diagram of the underwater concrete pouring process in this embodiment. Detailed Implementation

[0022] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0023] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0024] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0025] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] Please see Figure 1 The diagram shown is a flowchart of the construction method for an environmentally friendly, anti-collapse temporary bridge according to this embodiment. This embodiment provides a construction method for an environmentally friendly, anti-collapse temporary bridge, including: Step S1: Assemble the various floating modules to form a flexible bridge deck body, and lay the flexible bridge deck body on the river surface at the temporary bridge river. Fix both ends of the bridge deck body to the banks of the river. Determine the number of bridge deck support points and the corresponding riverbed construction position of each support point according to the length of the bridge deck body. Step S2: Insert the sheet metal bucket into the construction location on the riverbed, and excavate the riverbed inside the sheet metal bucket using an underwater tunneling device. Calculate the tunneling resistance evaluation value based on the set tunneling speed of the underwater tunneling device and the real-time tunneling speed during tunneling, and adjust the set tunneling speed of the underwater tunneling device in real time based on the tunneling resistance evaluation value. Step S3: Control the real-time sand pumping power of the sand pumping pump according to the preset sand pumping matching coefficient and the set tunneling speed of the underwater tunneling device. The sand pumping pumps out the loose mud and sand inside the iron bucket during tunneling and discharges it to the riverbank. The real-time river water turbidity at the construction site is detected by a turbidity detector set on the outside of the iron bucket. The real-time river water turbidity and the initial river water turbidity are calculated and judged to adjust the set tunneling speed or the preset sand pumping matching coefficient of the underwater tunneling device in real time. Step S4: Insert the supporting steel pipe column into the iron bucket, so that the bottom of the supporting steel pipe column is lower than the riverbed plane. Pour the mixed underwater concrete into the pit formed in the iron bucket through the cavity inside the supporting steel pipe column. During pouring, lift the iron bucket to the preset height. After the iron bucket is lifted, pour the underwater concrete until it fills the iron bucket. After the underwater concrete solidifies, fix the supporting steel pipe column and start construction at the riverbed construction position corresponding to the next support point. Step S5: Fix each fixed supporting steel pipe column to the corresponding bridge deck support point, and use angle steel to weld it to two adjacent supporting steel pipe columns to perform lateral reinforcement of the supporting steel pipe columns, thus completing the construction of the temporary bridge.

[0027] By employing a floating bridge deck, the construction of temporary bridges is facilitated. Supports are installed beneath the floating deck to significantly enhance its load-bearing capacity, preventing collapse due to load or span limitations. Furthermore, metal drums are used to stabilize the riverbed sediment, minimizing the impact of river flow on the excavation. Simultaneously, the excavation process involves dredging and sand removal within the excavation pit. The excavation resistance is calculated based on the real-time speed of the underwater tunneling device, allowing for feedback adjustments to the device's set speed. The set speed or preset dredging coefficient is adjusted according to the river's turbidity at the construction site to match the excavation efficiency with the dredging efficiency, reducing the impact of sediment erosion on the river environment. This method is more suitable for large-scale construction. Underwater construction is also more convenient than traditional river diversion or damming methods, ensuring rapid temporary bridge construction and stability while significantly protecting the original river ecosystem.

[0028] When calculating the number of support points based on the length of the main bridge deck, the buoyancy of the main bridge deck and the load-bearing capacity of the temporary bridge should also be considered. Taking a bridge deck made of simple polyethylene propylene pontoons as an example, one support should be set every 6 meters. In addition, for the lateral support points of the main bridge deck, the number of lateral support points can be set according to the width of the main bridge deck. Generally, one or two lateral support points are sufficient for bridge decks with a width of less than 3 meters. The specific setting should be based on the actual needs of use, which will not be elaborated here.

[0029] Please continue reading. Figure 2 As shown, it is a construction schematic diagram of riverbed excavation and sand dredging in this embodiment, including: underwater excavation device 1, iron bucket 2, sand dredging pump 3, riverbed plane 4, second turbidity detector 5, turbidity detector 6, and foundation pit excavation face 7. Specifically, in step S2, a standard resistance evaluation value is set, and the tunneling resistance evaluation value is calculated based on the set tunneling speed and the real-time tunneling speed of the underwater tunneling device. If the tunneling resistance evaluation value is less than or equal to the standard resistance evaluation value, then there is no need to adjust the set tunneling speed of the underwater tunneling device; If the tunneling resistance evaluation value is greater than the standard resistance evaluation value, the set tunneling speed of the underwater tunneling device will be adjusted in real time according to the tunneling resistance evaluation value. Wherein, Ns = (Vc - Vs) / Vc, Ns is the tunneling resistance evaluation value, Vc is the set tunneling speed, Vs is the real-time tunneling speed, Vc' = Vc - Vc × (Ns - Nb) / Nb, Vc' is the adjusted set tunneling speed, and Nb is the standard resistance evaluation value.

[0030] By calculating the ratio of the difference between the set tunneling speed and the actual real-time tunneling speed of the underwater tunneling device, the tunneling resistance evaluation value is calculated to indirectly characterize the riverbed condition during underwater excavation. The real-time tunneling resistance evaluation value is then compared with the set standard resistance evaluation value to determine whether the current excavation state of the underwater tunneling device is within the standard state. The set tunneling speed is adjusted in real time to increase the drilling torque by increasing the drilling speed of the underwater tunneling device, thereby responding to the riverbed condition in real time and ensuring the efficiency of riverbed excavation.

[0031] The standard resistance evaluation value is positively correlated with the load-bearing capacity of the underwater tunneling equipment used. The standard resistance evaluation value represents the damage ratio of the rotational speed of the tunneling drill bit in the underwater tunneling equipment. The standard resistance evaluation value set for general underwater tunneling operations should not exceed 8%, that is, the tunneling resistance evaluation value Ns should be set below 0.08.

[0032] Specifically, in step S2, a minimum tunneling speed of the underwater tunneling device is set. When the set tunneling speed of the underwater tunneling device is adjusted in real time according to the tunneling resistance evaluation value, the adjusted set tunneling speed is compared with the minimum tunneling speed in real time. If the adjusted set tunneling speed is less than the minimum tunneling speed, the underwater tunneling device will be stopped for inspection. If the adjusted set tunneling speed is greater than or equal to the minimum tunneling speed, the underwater tunneling device will be controlled to tunnel at the adjusted set tunneling speed.

[0033] By setting a minimum tunneling speed, the stability of the adjustment process of the underwater tunneling device is ensured. Taking a tunneling drill bit with a diameter of 700mm as an example, the corresponding minimum speed is set to be no less than 12 revolutions. This avoids the tunneling drill bit speed adjustment method of the underwater tunneling device from becoming cyclical due to self-adjustment, resulting in unlimited speed reduction. This would not only lead to extremely low tunneling efficiency, but also affect the overall construction progress of the temporary bridge.

[0034] Specifically, in step S3, a sand dredging matching coefficient is preset. When the underwater tunneling device is tunneling the riverbed, the real-time sand dredging power is calculated based on the real-time setting of the tunneling speed of the underwater tunneling device and the sand dredging matching coefficient. The real-time sand dredging power is used to control the sand dredging pump to extract the mud and sand inside the iron barrel. Where Ps = R × Vi, Ps is the real-time sand dredging power, R is the preset sand dredging matching coefficient, Vi is the real-time set tunneling speed of the underwater tunneling device, and Vi is equal to Vc or Vc'.

[0035] By setting a sand dredging matching coefficient, the sand dredging efficiency of the sand pump can be matched with the drilling efficiency of the underwater tunneling device in real time. This prevents the sand and impurities drilled by the underwater tunneling device from overflowing from the metal bucket due to low sand dredging efficiency, while also preventing the rapid pumping of river water from the metal bucket due to high sand dredging efficiency, which could cause the river water outside the bucket to fill the bucket and stir up the riverbed. Therefore, real-time matching of the operating status of the underwater tunneling device and the sand pump can reduce the impact on the original river ecological environment during the construction of temporary bridges. The sand dredging matching coefficient is the ratio of the initial set power of the sand pump to the initial set drilling speed of the underwater tunneling device. It can also be manually adjusted according to the actual underwater sand dredging situation to prevent significant changes in the turbidity outside the metal bucket.

[0036] Specifically, in step S3, the turbidity detector is set at the upper edge of the outer side of the metal drum, and the upper edge of the metal drum is higher than the riverbed plane. Before the underwater tunneling device starts tunneling into the riverbed, the turbidity of the river water is collected as the initial river water turbidity. When the underwater tunneling device starts tunneling into the riverbed, the real-time river water turbidity outside the metal drum is detected. The change value of river water turbidity is calculated based on the initial river water turbidity and the real-time river water turbidity. Where Ua = Us - Uc, Ua is the change in river turbidity, Us is the real-time river turbidity, and Uc is the initial river turbidity.

[0037] Specifically, in step S3, a first preset turbidity change value and a second preset turbidity change value are set. The first preset turbidity change value is 100 NTU, and the second preset turbidity change value is 300 NTU. When the underwater tunneling device is tunneling the riverbed, the calculated turbidity change value of the river water will be determined based on the first preset turbidity change value and the second preset turbidity change value. If the change in river water turbidity is less than or equal to the first preset turbidity change value, then the set tunneling speed or the preset sand dredging matching coefficient of the underwater tunneling device will not be adjusted. If the change in river water turbidity is greater than the first preset turbidity change value and less than or equal to the second preset turbidity change value, the set tunneling speed of the underwater tunneling device will be adjusted according to the change in river water turbidity and the first preset turbidity change value. Where Vi' = Vi × [1 - (Ua - U1) / U1], Ua is the change value of river water turbidity, U1 is the first preset turbidity change value, Vi is the real-time set tunneling speed of the underwater tunneling device, Vi is equal to Vc or Vc', and Vi' is the adjusted real-time set tunneling speed of the underwater tunneling device. If the change in river water turbidity is greater than the second preset turbidity change value, the detection result of the second turbidity detector will be obtained for judgment, so as to adjust the preset sand dredging matching coefficient. By calculating the turbidity of the river water outside the metal bucket inserted into the riverbed, the underwater tunneling status can be determined in real time. When the change in river water turbidity is less than or equal to the first preset turbidity change value, it indicates that the construction process inside the bucket has little impact on the river water, so no adjustment is made to the construction. When the change in river water turbidity is between the first and second preset turbidity change values, it indicates that the construction process inside the bucket has already had a certain impact on the environment outside the bucket. Therefore, the construction workload is reduced by decreasing the rotation speed of the underwater tunneling device, ensuring the stability of the river water in the construction area, and reducing the impact on the river environment.

[0038] Specifically, in step S3, the second turbidity detector is positioned at the upper edge of the inner side of the tin drum, and the real-time turbidity inside the tin drum is detected using the second turbidity detector. If the real-time turbidity in the bucket is greater than or equal to the real-time turbidity of the river water, the sand dredging matching coefficient is increased and adjusted according to the change value of the river water turbidity and the second preset turbidity change value. Where R1=R×[1+(Ua-U2) / U2], R1 is the increased and adjusted sand dredging matching coefficient, R is the preset sand dredging matching coefficient, U2 is the second preset turbidity change value, and Ua is the change value of the river water turbidity. If the real-time turbidity in the bucket is less than the real-time turbidity of the river water, the sand dredging matching coefficient is reduced and adjusted according to the change value of the river water turbidity and the second preset turbidity change value. Here, R2=R×[1+(U2-Ua) / U2], R2 is the sand dredging matching coefficient after reduction and adjustment, R is the preset sand dredging matching coefficient, U2 is the second preset turbidity change value, and Ua is the change value of the river water turbidity.

[0039] When the change in river water turbidity exceeds the second preset turbidity change value, it indicates that the construction matching inside the bucket is severely unbalanced. Therefore, by comparing the turbidity inside and outside the iron bucket, the main impact of this turbidity change is determined. If the real-time turbidity inside the bucket is greater than or equal to the real-time river water turbidity, it indicates that the real-time sand dredging efficiency is low, and the silt inside the bucket cannot be discharged in time, resulting in silt overflow. If the real-time turbidity inside the bucket is less than the real-time river water turbidity, it indicates that the rapid emptying of the river water inside the bucket causes river water replenishment, affecting the water flow and agitation of the riverbed outside the bucket. Therefore, the sand dredging matching coefficient is adjusted accordingly to accurately control the sand dredging efficiency and reduce the impact of construction on the river environment.

[0040] Please continue reading. Figure 3 As shown, it is a construction diagram of underwater concrete pouring in this embodiment, including: 2 iron bucket, 4 riverbed plane, 8 supporting steel pipe column, 9 underwater concrete that has been poured, and 10 pit sidewall formed after the iron bucket is removed. Specifically, the metal drum is cylindrical with no lid at the top and no bottom at the bottom, and the supporting steel pipe column is a hollow tube. In step S4, the supporting steel pipe column is inserted into the internal space of the metal drum along its axis, without contacting the metal drum. The supporting steel pipe column is suspended and fixed above the river surface, and the preset height to which the metal drum is lifted is not less than three-quarters of the height of the metal drum.

[0041] Specifically, in step S4, when the metal bucket is lifted upwards, it is slowly pulled out at a fixed speed, and the fixed speed is not higher than the maximum lifting speed. Where F = Lt / 12, unit: meters / second, F is the maximum lifting speed, and Lt is the axial height of the iron drum.

[0042] By injecting underwater concrete into the supporting steel pipe columns, the underwater concrete can be accurately deposited in the foundation pit. By lifting the iron bucket containing the underwater concrete, the underwater concrete, which has a higher density than the sediment at the bottom of the riverbed, is compressed into the surrounding riverbed. At the same time, the river water, which has a lower density, is squeezed out to form a relatively stable underwater temporary pier, further improving the stability of the temporary bridge.

[0043] The present invention also provides a temporary bridge constructed based on any of the above-mentioned environmentally friendly anti-collapse temporary bridge construction methods, comprising a flexible bridge deck body formed by splicing several floating modules and capable of floating on the river surface, several fixed piers formed by underwater concrete solidification, several supporting steel pipe columns inserted into the fixed piers and connected to the bridge deck body, and several angle steels for connecting the supporting steel pipe columns.

[0044] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A construction method for an environmentally friendly, anti-collapse temporary bridge, characterized in that, include, Step S1: Assemble the various floating modules to form a flexible bridge deck body, and lay the flexible bridge deck body on the river surface at the temporary bridge river. Fix both ends of the bridge deck body to the banks of the river. Determine the number of bridge deck support points and the corresponding riverbed construction position of each support point according to the length of the bridge deck body. Step S2: Insert the sheet metal bucket into the construction location on the riverbed, and excavate the riverbed inside the sheet metal bucket using an underwater tunneling device. Calculate the tunneling resistance evaluation value based on the set tunneling speed of the underwater tunneling device and the real-time tunneling speed during tunneling, and adjust the set tunneling speed of the underwater tunneling device in real time based on the tunneling resistance evaluation value. Step S3: Control the real-time sand pumping power of the sand pumping pump according to the preset sand pumping matching coefficient and the set tunneling speed of the underwater tunneling device. The sand pumping pumps out the loose mud and sand inside the iron bucket during tunneling and discharges it to the riverbank. The real-time river water turbidity at the construction site is detected by a turbidity detector set on the outside of the iron bucket. The real-time river water turbidity and the initial river water turbidity are calculated and judged to adjust the set tunneling speed or the preset sand pumping matching coefficient of the underwater tunneling device in real time. Step S4: Insert the supporting steel pipe column into the iron bucket, so that the bottom of the supporting steel pipe column is lower than the riverbed plane. Pour the mixed underwater concrete into the pit formed in the iron bucket through the cavity inside the supporting steel pipe column. During pouring, lift the iron bucket to the preset height. After the iron bucket is lifted, pour the underwater concrete until it fills the iron bucket. After the underwater concrete solidifies, the supporting steel pipe column is fixed, and construction is carried out at the riverbed construction position corresponding to the next support point. Step S5: Fix each fixed supporting steel pipe column to the corresponding bridge deck support point, and use angle steel to weld it to two adjacent supporting steel pipe columns to carry out lateral reinforcement of the supporting steel pipe columns, thus completing the construction of the temporary bridge. The sand dredging matching coefficient is the ratio of the initial set power of the sand dredging pump to the initial set tunneling speed of the underwater tunneling device. In step S2, a standard resistance evaluation value is set, and the tunneling resistance evaluation value is calculated based on the set tunneling speed and the real-time tunneling speed of the underwater tunneling device. If the tunneling resistance evaluation value is less than or equal to the standard resistance evaluation value, then there is no need to adjust the set tunneling speed of the underwater tunneling device; If the tunneling resistance evaluation value is greater than the standard resistance evaluation value, the set tunneling speed of the underwater tunneling device will be adjusted in real time according to the tunneling resistance evaluation value. Where Ns = (Vc - Vs) / Vc, Ns is the tunneling resistance evaluation value, Vc is the set tunneling speed, Vs is the real-time tunneling speed, and Vc' = Vc - Vc × (Ns - Nb) / Nb, Vc' is the adjusted set tunneling speed, and Nb is the standard resistance evaluation value. In step S3, a sand dredging matching coefficient is preset. When the underwater tunneling device is tunneling the riverbed, the real-time sand dredging power is calculated based on the real-time setting of the tunneling speed and the sand dredging matching coefficient of the underwater tunneling device, and the real-time sand dredging power is used to control the sand dredging pump to extract the mud and sand inside the iron barrel. Where Ps = R × Vi, Ps is the real-time sand dredging power, R is the preset sand dredging matching coefficient, Vi is the real-time set tunneling speed of the underwater tunneling device, and Vi is equal to Vc or Vc'.

2. The construction method for the environmentally friendly, anti-collapse temporary bridge according to claim 1, characterized in that, In step S2, a minimum tunneling speed of the underwater tunneling device is set. When the set tunneling speed of the underwater tunneling device is adjusted in real time according to the tunneling resistance evaluation value, the adjusted set tunneling speed is compared with the minimum tunneling speed in real time. If the adjusted set tunneling speed is less than the minimum tunneling speed, the underwater tunneling device will be stopped for inspection. If the adjusted set tunneling speed is greater than or equal to the minimum tunneling speed, the underwater tunneling device will be controlled to tunnel at the adjusted set tunneling speed.

3. The construction method for the environmentally friendly, anti-collapse temporary bridge according to claim 2, characterized in that, In step S3, the turbidity detector is set at the upper edge of the outer side of the metal drum, and the upper edge of the metal drum is higher than the riverbed plane. The turbidity of the river water is collected as the initial turbidity of the river water before the underwater tunneling device starts tunneling into the riverbed. The real-time turbidity of the river water outside the metal drum is detected when the underwater tunneling device starts tunneling into the riverbed. The change value of the river water turbidity is calculated based on the initial turbidity and the real-time turbidity. Where Ua = Us - Uc, Ua is the change in river turbidity, Us is the real-time river turbidity, and Uc is the initial river turbidity.

4. The construction method for the environmentally friendly, anti-collapse temporary bridge according to claim 3, characterized in that, In step S3, a first preset turbidity change value and a second preset turbidity change value are set, and the first preset turbidity change value is less than the second preset turbidity change value. When the underwater tunneling device is tunneling the riverbed, the calculated turbidity change value of the river water will be determined based on the first preset turbidity change value and the second preset turbidity change value. If the change in river water turbidity is less than or equal to the first preset turbidity change value, then the set tunneling speed or the preset sand dredging matching coefficient of the underwater tunneling device will not be adjusted. If the change in river water turbidity is greater than the first preset turbidity change value and less than or equal to the second preset turbidity change value, the set tunneling speed of the underwater tunneling device will be adjusted according to the change in river water turbidity and the first preset turbidity change value. Where Vi' = Vi × [1 - (Ua - U1) / U1], Ua is the change value of river water turbidity, U1 is the first preset turbidity change value, Vi is the real-time set tunneling speed of the underwater tunneling device, Vi is equal to Vc or Vc', and Vi' is the adjusted real-time set tunneling speed of the underwater tunneling device. If the change in river water turbidity exceeds the second preset turbidity change value, the detection result of the second turbidity detector will be obtained for judgment, and the preset sand dredging matching coefficient will be adjusted.

5. The construction method for the environmentally friendly, anti-collapse temporary bridge according to claim 4, characterized in that, In step S3, the second turbidity detector is positioned at the upper edge of the inner side of the tin drum, and the real-time turbidity Ut inside the tin drum is detected using the second turbidity detector. If the real-time turbidity in the bucket is greater than or equal to the real-time turbidity of the river water, the sand dredging matching coefficient is increased and adjusted according to the change value of the river water turbidity and the second preset turbidity change value. Where R1=R×[1+(Ua-U2) / U2], R1 is the increased and adjusted sand dredging matching coefficient, R is the preset sand dredging matching coefficient, U2 is the second preset turbidity change value, and Ua is the change value of the river water turbidity. If the real-time turbidity in the bucket is less than the real-time turbidity of the river water, the sand dredging matching coefficient is reduced and adjusted according to the change value of the river water turbidity and the second preset turbidity change value. Here, R2=R×[1+(U2-Ua) / U2], R2 is the sand dredging matching coefficient after reduction and adjustment, R is the preset sand dredging matching coefficient, U2 is the second preset turbidity change value, and Ua is the change value of the river water turbidity.

6. The construction method for the environmentally friendly, anti-collapse temporary bridge according to claim 1, characterized in that, The metal drum is cylindrical with no lid at the top and no bottom at the bottom. The supporting steel pipe column is a hollow tube. In step S4, the supporting steel pipe column is inserted into the internal space of the metal drum along its axis. The supporting steel pipe column does not contact the metal drum. The supporting steel pipe column is suspended and fixed above the river surface. The preset height to which the metal drum is lifted is not less than three-quarters of the height of the metal drum.

7. The construction method for the environmentally friendly, anti-collapse temporary bridge according to claim 6, characterized in that, In step S4, the metal bucket is lifted upwards and then slowly pulled out at a fixed speed, with the fixed speed not exceeding the maximum lifting speed. Where F = Lt / 12, unit: meters / second, F is the maximum lifting speed, and Lt is the axial height of the iron drum.

8. A temporary bridge constructed using the construction method of any one of claims 1 to 7, characterized in that, It includes a flexible bridge deck main body formed by splicing several floating modules and capable of floating on the river surface, several fixed piers formed by underwater concrete solidification, several supporting steel pipe columns inserted into the fixed piers and connected to the bridge deck main body, and several angle steels for connecting the various supporting steel pipe columns.

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