Urban drainage box culvert repair construction opportunity optimization method

Abstract

The urban drainage box culvert repair construction opportunity optimization method comprises the steps that 1, the repair process construction period and the flow guide flow are selected; 2, box culvert flow space-time relation analysis is carried out; step 3, analyzing a diversion risk rate; 4, box culvert in-situ repair diversion wreck influence evaluation is carried out; 5, box culvert in-situ repair construction opportunity decision making is carried out; according to confluence analysis of the catchment flow of the town drainage box culvert, the town drainage box culvert repair construction opportunity optimization method is provided. The problems that in a current urban drainage box culvert construction scheme, construction organization is unreasonable due to improper construction opportunity selection, and urban functions are greatly influenced after a diversion risk event occurs are solved. According to the method, the risk of the construction scheme can be evaluated, the risk rate and the risk loss can be calculated, the optimal construction opportunity scheme is optimized in the risk evaluation results of multiple construction schemes in combination with factors such as the construction period and the urban function influence, and the risk and rationality of the construction opportunity are quantitatively evaluated and visually output.

Description

Technical Field

[0001] The invention relates to the technical field of urban box culvert repair construction, and in particular to a method for optimizing the construction timing of urban drainage box culvert repair construction. Background Art

[0002] After long-term use, urban drainage box culverts will have problems such as structural section damage, siltation of the flow section, and insufficient flow capacity, which require repair or restoration of their functions. However, due to the rapid changes in the urban superstructure, the tops of a large number of box culverts are not suitable for excavation and repair, and in-situ repair technology must be used for construction. During the in-situ construction of the box culvert, the water flow in the water box culvert needs to be diverted in sections to form a dry culvert pipe condition. This water diversion work is generally called construction diversion.

[0003] Specific box culvert structure repair processes include: mortar spraying, local resin repair, HDPE liner, 3S module method, spiral winding method, CIPP flip thermal curing, etc. Depending on the above box culvert repair processes, the required repair period also varies.

[0004] During the diversion period, the original water flow in the box culvert is diverted downstream through water pumps, gravity flow, etc. Since the discharge capacity is limited and difficult to increase quickly, if the water volume suddenly increases during the in-situ repair of the box culvert, a diversion failure event may occur, resulting in the overflow and loss of construction equipment and materials in the box culvert and urban sewage.

[0005] Therefore, it is necessary to consider the in-situ repair process of the box culvert, the precipitation and water collection conditions at the project location, comprehensively analyze the water inflow and diversion conditions during the box culvert repair period, and propose a risk analysis method for the construction timing of in-situ repair of urban drainage box culverts based on diversion risk, combined with the construction timing optimization decision method. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for optimizing the construction timing of urban drainage box culvert repair. Based on the representative annual precipitation data of the city, the flow change process of the watershed data is analyzed, and the Monte-Carlo method is used for risk analysis to establish a risk analysis model and a risk assessment system. Then, the multi-attribute decision-making method is used to comprehensively consider the program factors of the construction timing and select the best program from many construction timings.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] The optimization method for the construction timing of urban drainage box culvert repair includes the following steps:

[0009] Step 1: Select the repair process period and diversion flow rate. According to the box culvert repair construction process and diversion plan, determine the required diversion period and the maximum flow rate that the construction diversion can carry;

[0010] Step 2: Analyze the spatiotemporal relationship of box culvert flow. Divide the construction period that meets the needs of the repair plan, collect precipitation data, and analyze the uncertainty of precipitation flow in each construction period. According to the change law of domestic sewage with time and season within the box culvert catchment area, analyze the uncertainty of domestic sewage flow in each construction period, and combine the uncertainty of precipitation flow and domestic sewage flow to analyze and calculate the box culvert catchment flow:

[0011] Q=Q 雨 +Q 污 ;

[0012] Where: Q is the total flow of the box culvert, m 3 / s;Q 雨 is the precipitation flow; Q 污 is the flow of domestic sewage; Step 3, diversion risk rate analysis; Monte Carlo method is used as the risk solution method, considering the uncertainty of precipitation flow and domestic sewage flow, random sampling is performed on the box culvert catchment flow, and the maximum discharge flow is deduced according to the water balance equation, and compared with the maximum flow that can be carried by the construction diversion of the in-situ repair of the box culvert, to determine the risk status of the diversion system; based on multiple samplings, the diversion risk rate under the corresponding construction plan and construction period conditions is obtained, and a diversion risk rate analysis model for in-situ repair of the box culvert is established;

[0013] Step 4: Impact assessment of the box culvert in-situ repair and drainage incident: Based on the box culvert in-situ repair construction plan, analyze the impact of the box culvert in-situ repair and drainage incident on sewage overflow, construction machinery and material damage, urban environment and pollution, and evaluate the economic losses and social impact of the box culvert in-situ repair and drainage incident, that is, the loss C generated after the risk occurs in the repair process s during the nth construction period;

[0014] Step 5. Decision on the timing of the in-situ repair of the box culvert. Based on the diversion risk rate and accident consequences of the in-situ repair construction plan of the box culvert, quantitatively evaluate the construction cost, risk rate, accident loss and other attributes of each plan, consider the decision maker's preferences, establish a multi-attribute decision model for the timing of the in-situ repair of the box culvert, and recommend the repair construction plan and construction timing with the best comprehensive conditions.

[0015] The specific steps of Step 2 above are as follows:

[0016] Step 2.1, classify and number all the catchment data according to the construction period, cluster the catchment data within a construction period, and obtain the catchment data set of different construction schedules;

[0017] Step 2.2, according to the catchment data set in Step 2.1, the catchment flow data of the first construction schedule is processed by P-Ⅲ distribution curve, and the corresponding parameter Cv value and Cs value are selected to draw a suitable theoretical frequency curve of flow;

[0018] Step 2.3, repeat step 2.2, and perform P-Ⅲ distribution curve processing on the water flow data of the remaining construction period to obtain the theoretical frequency curve of water flow for all construction schedules.

[0019] In the above Step 3:

[0020] The repair construction risk of the nth construction period corresponding to the construction opportunity k for:

[0021]

[0022] Where: f is the risk assessment function; is the hydrological risk factor for construction opportunity k corresponding to construction period n; is the risk loss of construction opportunity k corresponding to construction period n;

[0023] During the diversion period, the probability that the upstream water flow exceeds the maximum discharge capacity of the diversion pipe is the box culvert diversion risk P. f :

[0024] P f =P(Q max >Q X );

[0025] Where: Q max is the maximum flow of upstream catchment; Q X Design discharge capacity for box culvert construction.

[0026] The formula for risk loss in Step 4 above is:

[0027]

[0028] Where: is the risk loss of the kth construction opportunity during the nth construction period; is the cost investment of repairing the kth construction opportunity using repair method s during the nth construction period; is the risk loss degree of process s in the nth construction period; β n is a risk variable, which is 1 if a risk occurs during construction and 0 if no risk occurs.

[0029] The specific steps of Step 3 above are as follows:

[0030] Step 3.1. According to the water flow process curve and flow rate theoretical frequency curve of the first construction schedule, a random number X is drawn. i , calculate X i Flow rate Q corresponding to frequency i , select the closest to X in the catchment data set i Construction period corresponding to the flow rate;

[0031] Step 3.2, according to the random flow Q i Amplify the data with the same ratio as the flow rate during the catchment process of random flow, and draw the catchment process curve corresponding to the random flow;

[0032] Step 3.3, according to the water balance equation of the water flow and diversion discharge flow, it is assumed that the discharge capacity is provided by the water pump, which is a fixed value Q out , then the maximum value Q of the water flow in the box culvert during the construction period can be calculated step by step max ; Step 3.4, repeat Step 3.1 to Step 3.3 for n times, and obtain n groups of random sampling corresponding to the water flow process curve and n maximum water flow Q max , compare n data horizontally, among which there are m values ​​exceeding the maximum diversion value q of the diversion design scheme, and obtain the risk rate of the target box culvert in the first construction period arrangement scheme; perform N simulations, if the diversion system fails n f times, then the risk rate of in-situ repair of box culvert is P f for:

[0033]

[0034] Step 3.5. Repeat Step 3.1 to Step 3.4 to calculate the risk rate of the box culvert repair construction corresponding to the remaining construction schedule.

[0035] The present invention provides a method for optimizing the construction timing of urban drainage box culvert repairs. Based on the integrated analysis of the water flow of urban drainage box culverts, a method for optimizing the construction timing of urban drainage box culvert repairs is proposed. It aims to reduce the problems of unreasonable construction organization caused by inappropriate construction timing selection in the current urban drainage box culvert construction plan, resulting in idle work, and the great impact on urban functions after the diversion risk event occurs. The present invention can evaluate the risks of the construction plan, calculate the risk rate and risk loss, and in the risk assessment results of multiple construction plans, combine factors such as construction period and urban function impact to select the optimal construction timing plan, quantitatively evaluate and visualize the output of the risk and rationality of the construction timing. The method of the present invention takes into account the box culvert water flow information and the construction diversion plan. The application of the method of the present invention will improve the rationality of the selection of construction plans, reduce the impact of box culvert repair construction on urban functions, and improve the scientific nature of the field of urban box culvert repair projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0037] Figure 1 This is a schematic diagram of the algorithm flow of the model of the present invention;

[0038] Figure 2 The curve showing the variation of the test risk at each timing with the test timing in the embodiment;

[0039] Figure 3 The curve of construction risk loss at each opportunity corresponding to the 6-day box culvert construction period in the embodiment varies with the construction opportunity. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0041] The optimization method for the construction timing of urban drainage box culvert repair includes the following steps:

[0042] Step 1: Select the repair process period and diversion flow rate. According to the box culvert repair construction process and diversion plan, determine the required diversion period and the maximum flow rate that the construction diversion can carry;

[0043] Step 2: Analyze the spatiotemporal relationship of box culvert flow. Divide the construction period that meets the needs of the repair plan, collect precipitation data, and analyze the uncertainty of precipitation flow in each construction period. According to the change law of domestic sewage with time and season within the box culvert catchment area, analyze the uncertainty of domestic sewage flow in each construction period, and combine the uncertainty of precipitation flow and domestic sewage flow to analyze and calculate the box culvert catchment flow:

[0044] Q=Q 雨 +Q 污 ;

[0045] Where: Q is the total flow of the box culvert, m 3 / s;Q 雨 is the precipitation flow; Q 污 is the flow of domestic sewage; Step 3, diversion risk rate analysis; Monte Carlo method is used as the risk solution method, considering the uncertainty of precipitation flow and domestic sewage flow, random sampling is performed on the box culvert catchment flow, and the maximum discharge flow is deduced according to the water balance equation, and compared with the maximum flow that can be carried by the construction diversion of the in-situ repair of the box culvert, to determine the risk status of the diversion system; based on multiple samplings, the diversion risk rate under the corresponding construction plan and construction period conditions is obtained, and a diversion risk rate analysis model for in-situ repair of the box culvert is established;

[0046] Step 4: Impact assessment of the box culvert in-situ repair and drainage incident: Based on the box culvert in-situ repair construction plan, analyze the impact of the box culvert in-situ repair and drainage incident on sewage overflow, construction machinery and material damage, urban environment and pollution, and evaluate the economic losses and social impact of the box culvert in-situ repair and drainage incident, that is, the loss C generated after the risk occurs in the repair process s during the nth construction period;

[0047] Step 5. Decision on the timing of the in-situ repair of the box culvert. Based on the diversion risk rate and accident consequences of the in-situ repair construction plan of the box culvert, quantitatively evaluate the construction cost, risk rate, accident loss and other attributes of each plan, consider the decision maker's preferences, establish a multi-attribute decision model for the timing of the in-situ repair of the box culvert, and recommend the repair construction plan and construction timing with the best comprehensive conditions.

[0048] The specific steps of Step 2 above are as follows:

[0049] Step 2.1, classify and number all the catchment data according to the construction period, cluster the catchment data within a construction period, and obtain the catchment data set of different construction schedules;

[0050] Step 2.2, according to the catchment data set in Step 2.1, the catchment flow data of the first construction schedule is processed by P-Ⅲ distribution curve, and the corresponding parameter Cv value and Cs value are selected to draw a suitable theoretical frequency curve of flow;

[0051] Step 2.3, repeat step 2.2, and perform P-Ⅲ distribution curve processing on the water flow data of the remaining construction period to obtain the theoretical frequency curve of water flow for all construction schedules.

[0052] In the above Step 3:

[0053] The repair construction risk of the nth construction period corresponding to the construction opportunity k for:

[0054]

[0055] Where: f is the risk assessment function; is the hydrological risk factor for construction opportunity k corresponding to construction period n; is the risk loss of construction opportunity k corresponding to construction period n;

[0056] During the diversion period, the probability that the upstream water flow exceeds the maximum discharge capacity of the diversion pipe is the box culvert diversion risk P. f :

[0057] P f =P(Q max >Q X );

[0058] Where: Q max is the maximum flow of upstream catchment; Q X Design discharge capacity for box culvert construction.

[0059] The formula for risk loss in Step 4 above is:

[0060]

[0061] Where: is the risk loss of the kth construction opportunity during the nth construction period; is the cost investment of repairing the kth construction opportunity using repair method s during the nth construction period; is the risk loss degree of process s in the nth construction period; β n is a risk variable, which is 1 if a risk occurs during construction and 0 if no risk occurs.

[0062] The specific steps of Step 3 above are as follows:

[0063] Step 3.1. According to the water flow process curve and flow rate theoretical frequency curve of the first construction schedule, a random number X is drawn. i , calculate X i Flow rate Q corresponding to frequency i , select the closest to X in the catchment data set i Construction period corresponding to the flow rate;

[0064] Step 3.2, according to the random flow Q i Amplify the data with the same ratio as the flow rate during the catchment process of random flow, and draw the catchment process curve corresponding to the random flow;

[0065] Step 3.3, according to the water balance equation of the water flow and diversion discharge flow, it is assumed that the discharge capacity is provided by the water pump, which is a fixed value Q out , then the maximum value Q of the water flow in the box culvert during the construction period can be calculated step by step max ; Step 3.4, repeat Step 3.1 to Step 3.3 for n times, and obtain n groups of random sampling corresponding to the water flow process curve and n maximum water flow Q max , compare n data horizontally, among which there are m values ​​exceeding the maximum diversion value q of the diversion design scheme, and find the risk rate of the target box culvert in the first construction period arrangement scheme. Perform N simulations. If the diversion system fails n f times, then the risk rate of in-situ repair of box culvert is P f for:

[0066]

[0067] Step 3.5. Repeat Step 3.1 to Step 3.4 to calculate the risk rate of the box culvert repair construction corresponding to the remaining construction schedule.

[0068] Example:

[0069] The network of urban underground drainage box culverts has complex spatial distribution, is difficult to repair without trenching, and is greatly affected by precipitation. This note conducts a repair test of an old box culvert in City X. The repaired box culvert has 6 inspection wells, 1 discharge outlet, and several unknown branches. The ground buildings above the box culvert include residential areas, commercial streets, urban traffic arteries, and important urban railway hubs. There are many factors to consider and a wide range of coverage, which is representative in the in-situ repair test of box culverts.

[0070] Step 1: The test schedule is a total of 108 days, with the main time span from January to April. The timing selection optimization focuses on the test schedule factors, focusing on the delay in the schedule, and increasing the weight of the impact of the delay in the schedule on the excess construction time. Since the box culvert here is responsible for the collection and drainage of rainwater and domestic sewage, the construction of the box culvert needs to ensure the daily water use of residents. At the same time, the discharge of domestic sewage will vary with the daily water use period, so the test needs to avoid some peak water use periods, and the repair time is difficult to reach the normal 4 days. At the same time, the construction conditions of some construction sections of this section of the box culvert are poor, the inspection well is deep in the alley, and the length of the section to be repaired of the box culvert is long, which also leads to a long construction period for this section of the box culvert. According to the actual situation of the construction site investigation, the repair cycle data of each construction section of this section of the box culvert are shown in Table 1.

[0071] Table 1:

[0072]

[0073] Step 2: Select the representative annual data of this city. The data accuracy is to record precipitation every 5 minutes. The total precipitation for 365 days in a year is 1460.6 mm, and the number of days with precipitation in a year is 151. After preprocessing, the excerpt of daily precipitation data is shown in Table 2.

[0074] Table 2:

[0075]

[0076] Based on the relevant information and data of the city's per capita sewage discharge, the daily sewage discharge is divided into four time periods, and the corresponding relationships between the per capita sewage discharge are shown in Table 3.

[0077] Table 3:

[0078]

[0079] According to the formula Q = Q雨 +Q 污 The combination of rainwater flow and sewage flow is the average flow rate of the box culvert during the period, as shown in Table 4.

[0080] Table 4:

[0081]

[0082] Step 3: According to the results of the water flow analysis, randomly select different flow rates to calculate the corresponding water flow process lines, comprehensively consider the hydrological random factors of the diversion system, and use the Monte Carlo method to simulate and obtain the risk rate of construction diversion failure corresponding to the construction timing. When the Monte Carlo method is used to simulate the risk, the probability of the risk of box culvert construction diversion should be calculated. If a risk occurs, the risk loss generated when the risk occurs should be calculated. The above experimental results are shown in Table 5.

[0083] Table 5:

[0084]

[0085]

[0086] Step 4: From the analysis of Step 3, it can be obtained that during the test period of this section of box culvert, taking the construction period of 6 days as an example, the curve of the test risk at each time as a function of the test time is shown in Figure 2 .

[0087] The construction period of this box culvert is 6 days. The curve of construction risk loss at each time is as follows: Figure 3 .

[0088] Step 5: Based on the timing influencing factors and timing selection optimization decision indicators, the design alternatives for construction timing are screened out (see Table 6).

[0089] Table 6:

[0090]

[0091] The obtained timing reference scheme is shown in Table 7.

[0092] Table 7:

[0093]

[0094]

[0095] Note: In the reference plan, i and j refer to the start and end days of construction for each construction opportunity, respectively, starting from the first day of the year. For example, (101,106) means that construction starts on the 101st day and ends on the 106th day, which corresponds to the construction opportunities of April 9-April 14.

Claims

1. A method for optimizing the construction timing of urban drainage box culvert repair, characterized in that: The steps include: Step 1: Select the repair process period and diversion flow rate. According to the box culvert repair construction process and diversion plan, determine the required diversion period and the maximum flow rate that the construction diversion can carry; Step 2: Analyze the spatiotemporal relationship of box culvert flow. Divide the construction period that meets the needs of the repair plan, collect precipitation data, and analyze the uncertainty of precipitation flow in each construction period. According to the change law of domestic sewage with time and season within the box culvert catchment area, analyze the uncertainty of domestic sewage flow in each construction period, and combine the uncertainty of precipitation flow and domestic sewage flow to analyze and calculate the box culvert catchment flow: Q=Q 雨 +Q 污 ; Where: Q is the total flow of the box culvert, m 3 / s;Q 雨 is the precipitation flow; Q 污 is the flow rate of domestic sewage; Step 3: diversion risk rate analysis: Monte Carlo method is used as the risk solution method. Considering the uncertainty of precipitation flow and domestic sewage flow, random sampling is performed on the box culvert catchment flow, and the maximum discharge flow is deduced based on the water balance equation. The maximum discharge flow is compared with the maximum flow that can be carried by the construction diversion of the in-situ repair of the box culvert to determine the risk status of the diversion system. Based on multiple sampling, the diversion risk rate under the corresponding construction scheme and construction period conditions is obtained, and a diversion risk rate analysis model for in-situ repair of box culverts is established; Step 4: Impact assessment of the box culvert in-situ repair and drainage incident: Based on the box culvert in-situ repair construction plan, analyze the impact of the box culvert in-situ repair and drainage incident on sewage overflow, construction machinery and material damage, urban environment and pollution, and evaluate the economic losses and social impact of the box culvert in-situ repair and drainage incident, that is, the loss C generated after the risk occurs in the repair process s during the nth construction period; Step 5. Decision on the timing of the in-situ repair of the box culvert. Based on the diversion risk rate and accident consequences of the in-situ repair construction plan of the box culvert, quantitatively evaluate the construction cost, risk rate, accident loss and other attributes of each plan, consider the decision maker's preferences, establish a multi-attribute decision model for the timing of the in-situ repair of the box culvert, and recommend the repair construction plan and construction timing with the best comprehensive conditions.

2. The method for optimizing the construction timing of urban drainage box culvert repair according to claim 1, characterized in that: The specific steps of Step 2 are as follows: Step 2.1, classify and number all the catchment data according to the construction period, cluster the catchment data within a construction period, and obtain the catchment data set of different construction schedules; Step 2.2, according to the catchment data set in Step 2.1, the catchment flow data of the first construction schedule is processed by P-Ⅲ distribution curve, and the corresponding parameter Cv value and Cs value are selected to draw a suitable theoretical frequency curve of flow; Step 2.3, repeat step 2.2, and perform P-Ⅲ distribution curve processing on the water flow data of the remaining construction period to obtain the theoretical frequency curve of water flow for all construction schedules.

3. The method for optimizing the construction timing of urban drainage box culvert repair according to claim 2, characterized in that: In the Step 3: The repair construction risk of the nth construction period corresponding to the construction opportunity k for: Where: f is the risk assessment function; is the hydrological risk factor for construction opportunity k corresponding to construction period n; is the risk loss of construction opportunity k corresponding to construction period n; During the diversion period, the probability that the upstream water flow exceeds the maximum discharge capacity of the diversion pipe is the box culvert diversion risk P. f : P f =P(Q max >Q X ); Where: Q max is the maximum flow of upstream catchment; Q X Design discharge capacity for box culvert construction.

4. The method for optimizing the construction timing of urban drainage box culvert repair according to claim 3, characterized in that: The formula for risk loss in Step 4 is: Where: is the risk loss of the kth construction opportunity during the nth construction period; is the cost investment of repairing the kth construction opportunity using repair method s during the nth construction period; is the risk loss degree of process s in the nth construction period; β n is a risk variable, which is 1 if a risk occurs during construction and 0 if no risk occurs.

5. The method for optimizing the construction timing of urban drainage box culvert repair according to claim 4, characterized in that: The specific steps of Step 3 are as follows: Step 3.

1. According to the water flow process curve and flow rate theoretical frequency curve of the first construction schedule, a random number X is drawn. i , calculate X i Flow rate Q corresponding to frequency i , select the closest to X in the catchment data set i Construction period corresponding to the flow rate; Step 3.2, according to the random flow Q i Amplify the data with the same ratio as the flow rate during the catchment process of random flow, and draw the catchment process curve corresponding to the random flow; Step 3.3, according to the water balance equation of the water flow and diversion discharge flow, it is assumed that the discharge capacity is provided by the water pump, which is a fixed value Q out , then the maximum value Q of the water flow in the box culvert during the construction period can be calculated step by step max ; Step 3.4, repeat Step 3.1 to Step 3.3 for n times, and obtain n groups of random sampling corresponding to the water flow process curve and n maximum water flow Q max , compare n data horizontally, among which there are m values ​​exceeding the maximum diversion value q of the diversion design scheme, and obtain the risk rate of the target box culvert in the first construction period arrangement scheme; perform N simulations, if the diversion system fails n f times, then the risk rate of in-situ repair of box culvert is P f for: Step 3.

5. Repeat Step 3.1 to Step 3.4 to calculate the risk rate of the box culvert repair construction corresponding to the remaining construction schedule.

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