Deep foundation pit earthwork excavation and internal support erection coordinated construction progress management system

Abstract

The present application relates to construction progress management technical field, disclose deep foundation pit earthwork excavation and internal support erection collaborative construction progress management system, aiming at the same layer concrete support, call corresponding batch cement consumption parameter, correct the equivalent strength development time, integrate the equivalent development time of strength and crack resistance double control, match compensation maintenance measures according to difference interval;Collect the creep analysis basic data in the adjacent layered interval of concrete support, and calculate the unit creep force increment and the seepage coupling unit excavation depth axial force increment of static time, adjust the corresponding area precipitation rate and excavation subsection length;Estimate the estimated axial force variation of the area to be excavated, adjust the layered excavation thickness, excavation sequence and force cushion compaction degree correspondingly;Calculate the allowable excavation step length under three kinds of constraints respectively and take the minimum value to obtain the final dynamic excavation step length, calculate the dynamic allowable static time and support erection advance quantity synchronously, and execute closed loop correction according to the measured deviation ratio.

Description

Technical Field

[0001] This invention relates to the field of construction progress management technology, specifically to a collaborative construction progress management system for deep foundation pit excavation and internal support erection. Background Technology

[0002] In the current management of the construction progress of deep foundation pit excavation and internal support erection, the determination of the permissible strength of concrete support excavation mostly adopts the uniform standard of fixed age, without taking into account different structural locations, reinforcement density and environmental exposure conditions to correct the strength development rate. It also fails to quantify the coupled reduction effect of early-age temperature change amplitude and cement dosage on crack resistance performance. This can easily lead to insufficient strength in weak parts such as the junction of support and retaining piles, but misjudgment that the standard is met. The low crack resistance safety reserve can cause hidden dangers of early-age temperature microcracks. In existing technologies, compensatory maintenance measures often adopt a one-size-fits-all approach, failing to match gradient maintenance strategies based on the equivalent development time differences at various characteristic locations. This easily leads to problems such as over-maintenance in some areas or under-maintenance in weak areas, making it difficult to achieve the dual objectives of strength growth and crack resistance reserve through coordinated management. Furthermore, earthwork excavation operations and support axial force control are disconnected, failing to effectively separate the contribution ratios of soil viscosity creep and groundwater seepage to axial force growth. This makes it impossible to specifically match adjustment schemes for precipitation rates and excavation segment lengths, easily leading to abnormal accumulation of support axial force or soil softening that restricts excavation efficiency. Finally, there is a lack of consideration for secondary impacts caused by excavation of adjacent blocks within the same layer or by excavation of upper and lower layers. The quantitative transmission analysis of disturbance axial force lacks the establishment of disturbance transmission coefficients in both horizontal and vertical dimensions, making it difficult to accurately predict the axial force change in the area to be excavated. The layered excavation thickness, excavation sequence, and pre-stressing adjustment of the force transmission pad lack quantitative basis, making it impossible to actively mitigate the sudden change in support axial force caused by excavation disturbance. Most key construction parameters are statically set based on design experience, without constructing a dynamic calculation mechanism under three types of constraints: strength and crack resistance, seepage creep, and multi-dimensional disturbance. There is a lack of closed-loop correction logic for core parameters driven by measured deviations, making it difficult to dynamically optimize the excavation step length, allowable static time, and advance of support erection, and failing to achieve a coordinated balance between construction progress control and foundation pit structural safety assurance. Therefore, a collaborative construction progress management system for deep foundation pit excavation and internal support erection is needed. Summary of the Invention

[0003] The purpose of this invention is to provide a collaborative construction progress management system for deep foundation pit excavation and internal support erection. This system constructs a dual-control logic for strength and crack resistance, equivalent development time determination, couples the calculation of the contribution ratio of seepage creep axial force with the calculation of multi-dimensional secondary disturbance transmission coefficients, and constructs a closed-loop correction mechanism for dynamic construction parameters under three types of constraints. This achieves precise collaborative control of the dual objectives of safety and progress in deep foundation pit excavation and internal support erection. To solve the aforementioned problems in the prior art, this invention is implemented through the following technical solutions: The deep foundation pit excavation and internal support erection collaborative construction progress management system provided in this embodiment of the invention specifically includes the following modules: The calculation and maintenance module: For the same-layer concrete support, the corresponding batch of cement dosage parameters are retrieved, the equivalent strength development time is corrected and calculated, and the early-age crack resistance reduction parameters are calculated by combining the early-age temperature change amplitude value. The equivalent development time of strength and crack resistance dual control is obtained, and the compensation maintenance measures are matched according to the difference range. Analysis and control module: After the compensation and maintenance measures are completed, the creep analysis basic data of the adjacent layer interval of the concrete support is collected, and the creep axial force increment per unit static time and the seepage coupled axial force increment per unit excavation depth are calculated. The corresponding area dewatering rate and excavation segment length are adjusted. Prediction and optimization module: Based on the creep analysis data, calculate the horizontal secondary disturbance axial force transmission coefficient and the vertical secondary disturbance axial force transmission coefficient respectively, and predict the predicted axial force change in the area to be excavated, and adjust the layer excavation thickness, excavation sequence and force transmission pad compaction degree accordingly. Solution correction module: Combining the equivalent development time of strength and crack resistance dual control, the allowable excavation step length under the three types of constraints is calculated respectively, and the minimum value is taken to obtain the final dynamic excavation step length. The dynamic allowable static time and the advance of support erection are calculated simultaneously, and closed-loop correction is performed according to the measured deviation ratio.

[0004] The beneficial effects of this invention are: 1. Construct a dual-control logic for strength and crack resistance equivalent development time. Correct the equivalent strength development time by integrating temperature ratio over time with structural location parameters. Couple batch cement usage with early-age temperature variation amplitude to calculate crack resistance reduction parameters. Determine excavation permission by taking the minimum development time at typical support locations. This addresses the specific shortcomings of fixed-age homogenization, neglecting weak points such as the junction of supports and retaining piles, and the potential for early-age temperature micro-cracks due to insufficient crack resistance reserves. Match the gradient number of insulation layers and watering frequency based on the equivalent development time difference at each characteristic location to address the issues of one-size-fits-all curing control, insufficient curing of weak points, and excessive curing of non-critical areas. Calculate the creep axial force increment per unit static time and the seepage-coupled axial force increment per unit excavation depth separately. Adjust the dewatering rate and excavation segment length accordingly to address the pain points of being unable to separate the two types of axial force influencing factors and the lack of targeted control measures leading to abnormal axial force accumulation. 2. Construct a system for calculating the axial force transmission coefficient of horizontal and vertical secondary disturbances, quantify the change in axial force of erected supports caused by a unit excavation area, predict the axial force change in the area to be excavated, and optimize the excavation parameters and the compaction degree of the force transmission pad accordingly, thus solving the specific shortcomings of lacking quantitative basis for secondary disturbances and being unable to actively suppress sudden changes in axial force; establish a dynamic excavation step length calculation mechanism under three types of constraints, simultaneously output the allowable static time and the advance of support erection, and rely on the measured deviation ratio to correct the core parameters in a closed loop, thus solving the specific drawbacks of static solidification of construction parameters and inability to achieve dynamic coordination between progress control and structural safety. Attached Figure Description

[0005] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0006] Figure 1 This is a schematic diagram of the structure of the collaborative construction progress management system for deep foundation pit excavation and internal support erection provided in Embodiment 1 of the present invention. Detailed Implementation

[0007] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0008] Example 1: As Figure 1 As shown in the embodiment of the present invention, the collaborative construction progress management system for deep foundation pit excavation and internal support erection specifically includes the following modules: The calculation and maintenance module: For the same-layer concrete support, the corresponding batch of cement dosage parameters are retrieved, the equivalent strength development time is corrected and calculated, and the early-age crack resistance reduction parameters are calculated by combining the early-age temperature change amplitude value. The equivalent development time of strength and crack resistance dual control is obtained, and the compensation maintenance measures are matched according to the difference range.

[0009] In a specific embodiment, temperature acquisition devices are respectively installed at typical characteristic locations of the concrete support on the same floor; the typical characteristic locations of the concrete support include, but are not limited to: the middle of the concrete support member, the junction of the concrete support and the retaining pile, and the windward side of the concrete support under winter construction conditions.

[0010] A sampling point is set up at a typical characteristic location of the concrete support. The temperature acquisition device collects the real-time internal temperature of the concrete at the sampling point at a preset sampling interval and records the concrete pouring completion time at the sampling point. The cement content in the concrete mix proportion parameters corresponding to the sampling point is retrieved.

[0011] The actual pouring time interval from the completion of concrete pouring to the calculation time is determined. Within the actual pouring time interval, the temperature ratio between the measured internal temperature of the concrete at the sampling point and the preset standard curing temperature value is calculated. The obtained temperature ratio is integrated along the time dimension. The integration result is multiplied by the preset structural position development parameters to obtain the equivalent strength development time at the sampling point.

[0012] It should be noted that the preset structural location development parameters are pre-set according to the location of the collection point. The structural location development parameters include: structural complexity, reinforcement density and environmental exposure conditions. Different locations correspond to different values ​​of structural location development parameters.

[0013] Extract the daily maximum and minimum temperatures at the location of the sampling point within the preset early age period, calculate the daily temperature alternation amplitude, and then take the average value to obtain the average daily temperature alternation amplitude.

[0014] Calculate the ratio of the average daily temperature alternation amplitude to the preset crack resistance design reference temperature alternation amplitude, multiply the obtained ratio by the preset cement dosage influence parameter to obtain the reduction component; subtract the reduction component from the value 1 to obtain the early-age crack resistance reduction parameter at the location of the sampling point, and constrain the calculation result within the preset reduction parameter range.

[0015] The preset parameters affecting cement usage are pre-set based on the cement usage grade per cubic meter of concrete; the higher the cement usage, the larger the corresponding parameter value.

[0016] Multiply the equivalent strength development time at the typical characteristic location of the concrete support where the sampling point is located by the early-age crack resistance reduction parameter to obtain the equivalent development time of strength and crack resistance dual control. The equivalent development time of strength and crack resistance dual control reflects both the degree of development of the concrete's compressive strength and the level of its crack resistance reserve.

[0017] Extract the minimum development time of the equivalent development time of the strength and crack resistance dual control of all concrete supports in the same layer of concrete support. Compare the minimum development time with the preset strength attainment time. When the minimum development time is greater than or equal to the preset strength attainment time, it is determined that the current layer of concrete support has reached the excavation permit strength. Otherwise, it has not reached the excavation permit strength.

[0018] The minimum development time is used to determine the strength, avoiding the risk of some locations being deemed qualified despite insufficient strength due to the homogenization assumption. The focus is on covering the weakest part of the force transmission core at the junction of concrete support and retaining pile.

[0019] The crack resistance safety reserve of the concrete supports at the sampling point was assessed. The early-age crack resistance reduction parameters of typical characteristic locations of each concrete support were compared. The lower the early-age crack resistance reduction parameter, the worse the crack resistance safety reserve at the sampling point, and the higher the risk of microcracks caused by temperature changes.

[0020] Calculate the equivalent development time difference between the strength and crack resistance dual control equivalent development time of each typical characteristic location of the concrete support and the maximum equivalent development time of the same layer. Based on the magnitude of the equivalent development time difference, continuously calculate the compensation curing time of the typical characteristic location of the concrete support where the sampling point is located. The larger the equivalent development time difference, the longer the compensation curing time.

[0021] During the implementation of compensatory maintenance, the number of insulation covering layers and the frequency of watering are adjusted according to the preset difference range where the equivalent development time difference is located, so as to achieve differentiated continuous compensation and avoid the irrationality of sudden changes in maintenance measures near the threshold.

[0022] For example, in the preset structural position development parameters, the value of the middle part of the concrete support member is 1.0, the value of the junction of the concrete support and the retaining pile is 0.78, and the value of the windward side of the concrete support under winter construction conditions is 0.8; the preset standard curing temperature value is 20 degrees Celsius; the preset strength attainment time is 7 days; the preset early age period is 7 days; the preset crack resistance design reference temperature variation value is 10 degrees Celsius; the preset cement dosage influence parameter is 0.15 when the cement dosage is 350 kg per cubic meter; and the preset reduction parameter range is [0.7, 1.0].

[0023] Analysis and control module: After the compensation and maintenance measures are completed, the creep analysis basic data of adjacent layers of concrete support are collected, and the creep axial force increment per unit static time and the seepage coupled axial force increment per unit excavation depth are calculated. The corresponding area dewatering rate and excavation segment length are adjusted.

[0024] In a specific embodiment, creep analysis data of the area corresponding to the excavation operation is collected, and the support axial force monitoring device of the typical main support section of the foundation pit is used. After the excavation of the previous layer of earthwork is completed and the support axial force tends to stabilize, the initial stable support axial force is recorded. Before the excavation of the next layer of earthwork begins, the support axial force at the end of the resting period is recorded. The time interval between the two recording times is recorded simultaneously, which is the resting time.

[0025] Collect measured groundwater levels in the area corresponding to the excavation operation to obtain the groundwater level change range during adjacent layer excavation; simultaneously retrieve the excavation depth of the corresponding layer from the construction records.

[0026] The basic data for creep analysis include: support axial force, static time, and groundwater level change.

[0027] Calculate the difference between the support axial force at the end of the resting period before the start of the next layer and the initial stable support axial force after the completion of the previous layer. Divide the difference in support axial force by the resting time between two adjacent layers of excavation to obtain the creep axial force increment per unit resting time. The creep axial force increment per unit resting time reflects the average daily increase in axial force caused by the viscous creep characteristics of the soil itself.

[0028] Calculate the difference in support axial force between the current layer and the previous layer after excavation. Divide the difference in support axial force by the difference in excavation depth of the corresponding layer to obtain the measured axial force increment per unit excavation depth. Subtract the preset benchmark value of axial force increment per unit depth from the measured axial force increment per unit excavation depth to obtain the additional axial force increment outside of pure unloading.

[0029] The seepage contribution component is obtained by multiplying the preset groundwater level influence parameter by the groundwater level rise. The seepage contribution component is then added to the additional axial force increment to obtain the seepage-coupled axial force increment per unit excavation depth. The preset groundwater level influence parameter is pre-set according to the soil permeability characteristics of the excavation area. The stronger the soil permeability, the larger the corresponding parameter value.

[0030] The proportion of the seepage contribution component in the axial force increment per unit excavation depth of the seepage-coupled type is calculated to obtain the proportion of seepage influence; the remaining part is the soil creep contribution component, and the corresponding creep influence proportion is obtained.

[0031] Based on the planned settling time for subsequent layered excavation, and combined with the creep axial force increment per unit settling time, the pre-increase value of axial force during the corresponding settling period is calculated, and the pre-increase value of axial force is included in the prediction range of total axial force of concrete support.

[0032] Based on the remaining excavation depth and the incremental axial force per unit excavation depth under seepage coupling, the total axial force value of the concrete support after subsequent excavation is predicted; when the groundwater level rises, the incremental axial force per unit excavation depth under seepage coupling increases synchronously.

[0033] When the daily operating volume of the excavator is lower than the benchmark operating volume, the contribution of the corresponding influencing factors is matched according to the values ​​of the proportion of seepage influence and the proportion of creep influence. The higher the proportion of seepage influence, the greater the impact of soil softening on operating efficiency; the higher the proportion of creep influence, the greater the impact of soil viscous deformation on operating efficiency.

[0034] Based on the percentage of seepage impact, the precipitation rate of the corresponding precipitation wells is adjusted. The percentage of seepage impact is calculated, and the increase in precipitation rate is assigned on a one-to-one basis. That is, the percentage of seepage impact is equal to the increase in precipitation rate.

[0035] The higher the proportion of seepage influence, the greater the increase in precipitation rate. The mechanical property loss of soil softening is compensated by lowering the groundwater level. The segment length of layered excavation is adjusted according to the proportion of creep influence. The higher the proportion of creep influence, the shorter the segment length of a single excavation. Creep deformation is gradually released by small-step rapid excavation to avoid the concentrated accumulation of creep axial force.

[0036] For example, the preset benchmark value for axial force increment per unit depth is 120 kN / m; the preset groundwater level influence parameter is 0.4 in the silty soil layer; the difference in excavation depth between adjacent layers of the silty soil foundation pit is 2 meters, and the axial force of the support increases by 360 kN before and after excavation, corresponding to a measured increase of 180 kN / m in axial force per unit depth; during this period, the groundwater level rises by 1 meter, and the seepage contribution component is 400 N / m; the calculated axial force increment per unit excavation depth for seepage coupling is 100 kN / m, the seepage influence accounts for 40%, and the creep influence accounts for 60%; the corresponding adjustment measures are to increase the dewatering rate of the dewatering wells in the corresponding area by 40%, and at the same time shorten the length of the single excavation segment by 20%.

[0037] Prediction and optimization module: Based on creep analysis data, calculate the horizontal secondary disturbance axial force transmission coefficient and the vertical secondary disturbance axial force transmission coefficient respectively, and predict the predicted axial force change in the area to be excavated, and adjust the layer excavation thickness, excavation sequence and force transmission pad compaction degree accordingly.

[0038] In a specific embodiment, after the first excavation block is completed and the corresponding internal support is erected, the initial support axial force of the erected concrete support is recorded; after the excavation of adjacent blocks on the same floor is completed, the support axial force of the same concrete support is recorded again, and the single excavation depth and excavation width of adjacent blocks on the same floor are recorded simultaneously.

[0039] After the next layer of earthwork is excavated, the axial force of the same concrete support is recorded for the third time, and the single excavation depth and horizontal projection width of the next layer of earthwork are recorded simultaneously.

[0040] Calculate the difference in axial force between the excavation support after the excavation of adjacent blocks in the same layer is completed and before excavation. Divide the difference in axial force between the excavation support by the product of the single excavation depth and the excavation width of the adjacent blocks in the same layer to obtain the horizontal secondary disturbance axial force transmission coefficient. The horizontal secondary disturbance axial force transmission coefficient reflects the change in axial force of the erected support caused by a unit horizontal excavation area.

[0041] Calculate the difference between the axial force of the supports after the excavation of the next layer of earthwork is completed and the axial force of the supports of the previous layer before excavation. This yields the difference in axial force between adjacent supports. Divide the difference in axial force between adjacent supports by the product of the single excavation depth and the horizontal projection width of the next layer of earthwork to obtain the vertical secondary disturbance axial force transmission coefficient. The vertical secondary disturbance axial force transmission coefficient reflects the change in axial force of the upper-layer supports caused by a unit vertical excavation area.

[0042] By combining the horizontal secondary disturbance axial force transmission coefficient and the vertical secondary disturbance axial force transmission coefficient, the estimated axial force change in the area to be excavated is estimated. The estimated axial force change includes: the estimated horizontal axial force change and the estimated vertical axial force change. The area to be excavated includes: the horizontal blocks to be excavated and the vertical layers to be excavated.

[0043] For all horizontal blocks to be excavated, the estimated change in horizontal axial force corresponding to the existing concrete supports is calculated based on the designed excavation depth and width of the blocks and the horizontal secondary disturbance axial force transmission coefficient.

[0044] Specifically, the estimated change in horizontal axial force is obtained by multiplying the product of the designed excavation depth and the excavation width of the segment to be excavated by the horizontal secondary disturbance axial force transmission coefficient.

[0045] For all vertical layers to be excavated, the vertical axial force variation of the upper layer concrete support is calculated by combining the vertical secondary disturbance axial force transmission coefficient. By predicting the horizontal blocks to be excavated and the vertical layers to be excavated, the dynamic stress evolution law of the concrete support during the entire earthwork excavation process is restored.

[0046] Before excavation, for the horizontal blocks to be excavated, the layer excavation thickness and excavation sequence of the blocks to be excavated are adjusted according to the magnitude of the estimated change in horizontal axial force. The greater the estimated change in horizontal axial force, the smaller the layer excavation thickness. For the vertical layers to be excavated, the segment excavation length and excavation sequence of the layers to be excavated are adjusted according to the magnitude of the estimated change in vertical axial force. The greater the estimated change in vertical axial force, the smaller the segment excavation length.

[0047] A gradient excavation sequence is adopted, and excavation is gradually advanced from the side away from the erected support to the side closer to the support. The peak value of the disturbance axial force is reduced by optimizing the unloading sequence, avoiding the sudden change of axial force caused by a large-area unloading at one time, and realizing active pre-compensation on the excavation side.

[0048] For existing supports with large estimated horizontal or vertical axial force variations, adjustable force transmission pads are added at the junction of the support end and the retaining structure. The compaction of the pads is pre-adjusted according to the estimated axial force variation in the corresponding dimension. By pre-adding force transmission reserves, the increase in support axial force caused by excavation disturbance is reduced, and the fluctuation range of support axial force is controlled within the preset allowable fluctuation range of support axial force.

[0049] For example, the preset allowable fluctuation range of the support axial force is that the single increment is less than or equal to 300 kN. If the single excavation depth of adjacent blocks on the same layer is 3 meters and the excavation width is 8 meters, the initial axial force of the supports erected before excavation is 1100 kN, and the support axial force after excavation is 1340 kN, the calculated horizontal secondary disturbance axial force transmission coefficient is 10000 N / m². The single excavation depth of the next layer of earthwork is 3 meters and the horizontal projected width is 20 meters. After excavation, the upper layer supports... The axial force increases by 300 kN, and the calculated vertical secondary disturbance axial force transmission coefficient is 5000 N / m². If the designed width of the excavation block is 10 meters, the estimated change in axial force at the original design excavation depth is 300 kN. Corresponding pre-compensation measures are implemented: the layered excavation thickness is adjusted to 2.5 meters, and a gradient excavation sequence from far to near is adopted, which is expected to reduce the peak disturbance axial force by 15%. The force transmission pads at the corresponding support ends are pre-pressed 2 mm to reduce the increase in support axial force.

[0050] Solution correction module: Combining the equivalent development time of strength and crack resistance dual control, the allowable excavation step length under the three types of constraints is calculated respectively, and the minimum value is taken to obtain the final dynamic excavation step length. The dynamic allowable static time and the advance of support erection are calculated simultaneously, and closed-loop correction is performed according to the measured deviation ratio.

[0051] In a specific embodiment, the allowable excavation step length under three types of constraints is calculated respectively. The allowable excavation step length includes: allowable excavation step length under support strength and crack resistance constraints, allowable excavation step length under seepage creep coupled axial force constraints, and allowable excavation step length under multidimensional secondary disturbance constraints. The minimum value among the three types of allowable excavation step lengths is taken as the final dynamic excavation step length.

[0052] The minimum equivalent development time of strength and crack resistance dual control at all typical locations in the same layer is divided by the preset strength attainment time to obtain the strength reduction ratio; the preset excavation benchmark depth is multiplied by the strength reduction ratio to obtain the allowable excavation step length constrained by support strength and crack resistance performance.

[0053] Multiply the preset allowable single increment of axial force by the minimum value of the early-age crack resistance reduction parameter of the same layer to obtain the corrected allowable axial force increment; divide the corrected allowable axial force increment by the seepage-coupled axial force increment per unit excavation depth to obtain the seepage-creep coupled axial force constraint allowable excavation step length.

[0054] Calculate the axial force increment per unit width corresponding to the horizontal and vertical disturbances respectively, and take the larger value of the two to obtain the maximum value of the axial force increment per unit width; divide the corrected allowable axial force increment by the maximum value of the axial force increment per unit width to obtain the allowable excavation step length under the multidimensional secondary disturbance constraint.

[0055] Multiply the corrected allowable axial force increment by the preset upper limit of static creep ratio to obtain the allowable creep axial force increment during the static period; divide the allowable creep axial force increment during the static period by the creep axial force increment per unit static time to obtain the dynamic allowable static time.

[0056] Calculate the estimated vertical disturbance axial force caused by the excavation of the next layer, and multiply the ratio of the estimated vertical disturbance axial force to the corrected allowable axial force increment by the preset strength attainment time to obtain the dynamic erection lead time of the next internal support.

[0057] Establish a closed-loop mechanism for the entire process, and make dynamic corrections based on the measured data of the construction after each layer or block of excavation is completed.

[0058] Specifically, the deviation ratio between the measured axial force increment and the predicted axial force increment during this construction is calculated. Based on the deviation ratio, the secondary disturbance axial force transmission coefficient and creep increment parameters are adjusted accordingly. The larger the deviation, the greater the parameter adjustment range. When the deviation is positive, the corresponding coefficient is adjusted upward, and when the deviation is negative, the corresponding coefficient is adjusted downward. The secondary disturbance axial force transmission coefficient includes: the horizontal secondary disturbance axial force transmission coefficient and the vertical secondary disturbance axial force transmission coefficient.

[0059] The actual excavation depth of subsequent earthwork layers is adjusted according to the dynamic excavation step length. When the support strength is sufficient and the axial force risk is small, the benchmark excavation depth is maintained to accelerate the progress. When the axial force risk is high, the excavation depth is reduced to control safety, thereby achieving dynamic optimization of the excavation depth.

[0060] The interval between adjacent excavation layers is controlled by dynamically allowing the settling time to avoid excessive accumulation of soil creep axial force due to excessive settling time, while avoiding insufficient development of the support strength of the upper layer due to excessively short settling time, thus achieving a balance between construction period and safety.

[0061] Adjust the erection time of the next inner support according to the dynamic erection advance. When the vertical secondary disturbance is strong, erect the support in advance to form a support system to constrain the deformation of the retaining structure, offset the impact of the vertical secondary disturbance brought by the lower excavation, and avoid sudden changes in the axial force of the upper support.

[0062] For example, the preset excavation reference depth is 3 meters; the preset allowable single increment of axial force is 300,000 Newtons; the preset strength attainment time is 7 days; the preset maximum static creep ratio is 0.2; for a certain project, the calculated allowable excavation step length constrained by support strength and crack resistance performance is 2.8 meters, the allowable excavation step length constrained by seepage creep coupled axial force is 2.5 meters, and the allowable excavation step length constrained by multidimensional secondary disturbance is 2.7 meters. The minimum value of the three, 2.5 meters, is taken as the dynamic excavation step length; the creep axial force increment per unit static time is 12,000 Newtons per day, the minimum early-age crack resistance reduction parameter is 0.9, and the calculated dynamic allowable static time is 4.5 days; the estimated axial force increment under vertical secondary disturbance accounts for 30% of the allowable increment, and the calculated advance of the next internal support dynamic erection is 2.1 days.

[0063] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A collaborative construction progress management system for deep foundation pit excavation and internal support erection, characterized in that, Includes the following modules: The calculation and maintenance module: For the same-layer concrete support, the corresponding batch of cement dosage parameters are retrieved, the equivalent strength development time is corrected and calculated, and the early-age crack resistance reduction parameters are calculated by combining the early-age temperature change amplitude value. The equivalent development time of strength and crack resistance dual control is obtained, and the compensation maintenance measures are matched according to the difference range. The method for calculating the equivalent intensity development time is as follows: Determine the actual pouring time interval from the time the concrete pouring is completed to the calculation time, and the temperature ratio of the measured internal temperature of the concrete to the preset standard curing temperature value at each moment within the calculation interval. The temperature ratio is integrated along the time dimension, and the integral result is multiplied by the preset structural location development parameters to obtain the equivalent intensity development duration at the location of the sampling point. The method for obtaining the equivalent development time of the dual-control strength and crack resistance is as follows: Multiply the equivalent strength development time at the typical characteristic location of the concrete support where the sampling point is located by the early-age crack resistance reduction parameter to obtain the equivalent development time of dual control of strength and crack resistance; Extract the minimum equivalent development time of strength and crack resistance dual control at typical characteristic locations of all concrete supports in the same layer, compare the minimum development time with the preset strength attainment time, and complete the determination of the excavation permit strength of the concrete supports in the current layer. Analysis and control module: After the compensation and maintenance measures are completed, the creep analysis basic data of the adjacent layer interval of the concrete support is collected, and the creep axial force increment per unit static time and the seepage coupled axial force increment per unit excavation depth are calculated. The corresponding area dewatering rate and excavation segment length are adjusted. Prediction and optimization module: Based on creep analysis data, calculate the secondary disturbance axial force transmission coefficient and predict the predicted axial force change in the area to be excavated, and adjust the layer excavation thickness, excavation sequence and force transmission pad compaction degree accordingly. Solution correction module: Combining the equivalent development time of strength and crack resistance dual control, the allowable excavation step length under the three types of constraints is calculated respectively and the minimum value is taken to obtain the final dynamic excavation step length. The dynamic allowable static time and the advance of support erection are calculated simultaneously, and closed-loop correction is performed according to the measured deviation ratio. The method for performing closed-loop correction is as follows: The allowable excavation step length constrained by support strength and crack resistance performance, the allowable excavation step length constrained by seepage creep coupled axial force, and the allowable excavation step length constrained by multidimensional secondary disturbance are calculated respectively. The minimum value among the three types of allowable excavation step lengths is taken as the final dynamic excavation step length. Calculate the dynamic allowable static time and the advance of dynamic erection of the next internal support. After each layer or block of excavation is completed, calculate the deviation ratio between the measured axial force increment and the predicted axial force increment, and adjust the corresponding core parameters according to the deviation ratio.

2. The collaborative construction progress management system for deep foundation pit excavation and internal support erection according to claim 1, characterized in that, The method for calculating the early-age crack resistance reduction parameter is as follows: Extract the daily maximum and minimum temperatures at the locations of the sampling points within the preset early age period, calculate the daily temperature alternation amplitude, and take the average value to obtain the average daily temperature alternation amplitude. Calculate the ratio of the average daily temperature alternation amplitude to the preset crack resistance design reference temperature alternation amplitude. Multiply the obtained ratio by the preset cement dosage influence parameter to obtain the reduction component. Subtract the reduction component from the value 1 to obtain the early-age crack resistance reduction parameter. Constrain the calculation result within the preset reduction parameter range.

3. The collaborative construction progress management system for deep foundation pit excavation and internal support erection according to claim 1, characterized in that, The method for the creep axial force increment per unit resting time is as follows: After the previous layer of earthwork excavation is completed and the support axial force tends to stabilize, record the initial stable support axial force. Before the next layer of earthwork excavation begins, record the support axial force at the end of the static period. Simultaneously record the static duration at the two recording times. Calculate the difference between the axial force of the support at the end of the resting period and the initial stable support axial force, and divide the difference by the resting time to obtain the creep axial force increment per unit resting time.

4. The collaborative construction progress management system for deep foundation pit excavation and internal support erection according to claim 1, characterized in that, The method for increasing the axial force per unit excavation depth using the seepage coupling type is as follows: Collect measured groundwater level values ​​in the area corresponding to the excavation operation, obtain the groundwater level change range during adjacent layer excavation, retrieve the excavation depth of the corresponding layer from the construction record, and calculate the difference in support axial force between the current layer and the previous layer after excavation is completed. Divide the axial force difference by the corresponding layer's excavation depth difference to obtain the measured axial force increment per unit excavation depth. Subtract the preset unit depth axial force increment benchmark value from the measured unit depth axial force increment to obtain the additional axial force increment. The seepage contribution component is obtained by multiplying the preset groundwater level influence parameter by the groundwater level rise. The seepage contribution component is then added to the additional axial force increment to obtain the seepage-coupled axial force increment per unit excavation depth.

5. The collaborative construction progress management system for deep foundation pit excavation and internal support erection according to claim 1, characterized in that, The method for adjusting the precipitation rate and excavation segment length in the corresponding area is as follows: The proportion of seepage contribution in the unit excavation depth axial force increment of seepage-coupled type is obtained by calculating the proportion of seepage influence, and the remaining part is obtained as the proportion of creep influence. Adjust the dewatering rate of the dewatering wells in the corresponding area according to the proportion of seepage influence, and adjust the segment length of the layered excavation according to the proportion of creep influence.

6. The collaborative construction progress management system for deep foundation pit excavation and internal support erection according to claim 1, characterized in that, The method for calculating the axial force transmission coefficient of the secondary disturbance is as follows: After the first excavation block is completed and the corresponding internal support is erected, the initial support axial force of the erected concrete support is recorded. After the excavation of the adjacent blocks on the same floor is completed, the support axial force of the same concrete support is recorded again. Simultaneously, the single excavation depth and excavation width of the adjacent blocks on the same floor are recorded, and the difference in support axial force before and after the excavation of the adjacent blocks on the same floor is calculated. Dividing the axial force difference by the product of the single excavation depth and the excavation width yields the horizontal secondary disturbance axial force transmission coefficient; After the next layer of earthwork excavation is completed, the axial force of the same concrete support is recorded for the third time. At the same time, the single excavation depth and horizontal projection width of the next layer of earthwork are recorded, and the difference in axial force between the upper and lower layers before and after excavation is calculated. Divide the difference by the product of the single excavation depth and the horizontal projection width of the next layer to obtain the vertical secondary disturbance axial force transmission coefficient.

7. The collaborative construction progress management system for deep foundation pit excavation and internal support erection according to claim 1, characterized in that, The method for adjusting the thickness of the layered excavation, the excavation sequence, and the compaction degree of the force transmission pad is as follows: For all horizontal blocks to be excavated, the estimated change in horizontal axial force of the corresponding erected concrete supports is calculated by combining the horizontal secondary disturbance axial force transmission coefficient. For all vertical layers to be excavated, the estimated change in vertical axial force of the upper layer concrete supports is calculated by combining the vertical secondary disturbance axial force transmission coefficient. Adjust the layer excavation thickness and excavation sequence of the blocks to be excavated according to the estimated horizontal axial force change, and adjust the segment excavation length and excavation sequence of the layers to be excavated according to the estimated vertical axial force change. Add adjustable force transmission pads at the junction of the support end and the retaining structure, and fine-tune the compaction degree of the pads according to the estimated axial force change.

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