CN112446079A - Method for judging influence of poured concrete on dam forming safety - Google Patents
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Abstract
The invention discloses a method for judging the influence of poured concrete on dam-forming safety, which is characterized in that a three-dimensional rolled concrete gravity dam finite element model is established according to the structural characteristics of a typical dam section of a rolled concrete gravity dam, and the influence of the poured concrete on the dam-forming safety is analyzed by adopting ADINA finite element analysis software and considering the influence of the subsequent concrete pouring process, later stage water storage and crack existence. The invention provides a method for analyzing the influence of the poured concrete of a roller compacted concrete gravity dam on the safety of a dam, which can more accurately simulate the influence of factors such as a subsequent concrete pouring process, later stage water storage, crack existence and the like on the poured concrete, and can provide corresponding basis and support for the subsequent concrete pouring and the later stage water storage.
Description
Technical Field
The invention relates to a method for judging safety of a roller compacted concrete gravity dam, in particular to a method for judging influence of poured concrete on dam forming safety.
Background
The roller compacted concrete gravity dam is a new dam construction technology which develops rapidly since the eighties of the twentieth century, and is favored by the dam industry due to the characteristics of rapidness and economy. At present, the related research on the influence of factors such as the subsequent pouring process, the later stage water storage, the existence of cracks and the like on the quality of the poured roller compacted concrete is less, and the research is exactly concerned in the engineering construction process. Therefore, in order to ensure the smooth development of the subsequent concrete pouring and the subsequent water storage work, it is necessary to study the safety influence of the factors such as the subsequent pouring process, the subsequent water storage, the existence of cracks and the like on the poured roller compacted concrete.
Disclosure of Invention
The purpose of the invention is as follows: the invention aims to provide a method for judging the influence of poured concrete on dam-forming safety, and solves the problem that no method for judging the influence of the poured concrete on the dam-forming safety exists at present.
The technical scheme is as follows: the method for judging the influence of the poured concrete on the dam-forming safety comprises the following steps:
(1) establishing a three-dimensional rolled concrete gravity dam finite element model according to the specific size of a typical dam section of the rolled concrete gravity dam, and layering and grouping the established model according to the subsequent construction process and the dam body material partition;
(2) inputting preset material parameters, boundary conditions and gravity loads based on ADINA finite element analysis software, and performing finite element dead weight calculation on the poured concrete to obtain displacement and stress of the poured concrete under the action of dead weight, wherein the displacement comprises displacement along a river direction, displacement along a transverse river direction and displacement along a vertical direction, and the stress comprises vertical stress, first principal stress and third principal stress;
(3) calculating to obtain displacement and stress of the poured concrete at different pouring elevations on the basis of the calculation result of the step (2), wherein the displacement comprises displacement along the river, displacement along the river and displacement along the vertical direction, and the stress comprises vertical stress, first main stress and third main stress, drawing a relation curve between characteristic points at the heel and the site of the poured concrete along the river, the vertical displacement and the vertical stress and a subsequent pouring process according to the calculation result, and judging the safety state of the poured part of concrete in the subsequent pouring process according to the relation curve of the stress at the heel and the site of the dam;
(4) on the basis of the calculation result of the step (3), considering the influences of dead weight load, water load, sediment load, uplift pressure and wave pressure under the combined action of different loads, calculating to obtain the displacement and stress of the poured concrete under the combined action of each load, wherein the displacement comprises displacement along the river, displacement along the transverse river and displacement along the vertical direction, and the stress comprises vertical stress, first principal stress and third principal stress, drawing a relation curve of characteristic points at the dam heel and the dam site of the poured concrete along the river, the vertical displacement and the vertical stress and the later stage water storage process according to the calculation result, judging the safety state of the poured part of concrete in the later stage water storage process according to the relation curve of the stresses at the dam heel and the dam site, and solving the anti-slip stability safety coefficient between the poured concrete and the foundation as well as the newly poured part of concrete, comparing the safety coefficient obtained by calculation with a standard numerical value, and judging the stability condition of the poured concrete;
(5) according to the calculation result of the step (4), drawing a relation curve of node points at two sides of the crack to the river displacement, the vertical displacement and the vertical stress in the subsequent pouring process and the later stage water storage process, and judging the influence of the crack on the dam forming safety according to the relation of the node points at two sides of the crack to the displacement and the stress;
(6) and (5) finally judging whether the poured concrete meets the dam-forming safety requirement or not according to whether the judgment results of the steps (3) to (5) meet the safety requirement or not.
In the step (1), grouting galleries, drainage galleries and anti-seepage curtain structures are considered in the three-dimensional roller compacted concrete gravity dam finite element model, eight-node hexahedron units are adopted for space dispersion, 1 mm-wide penetrating crack units are preset in the model and are independently grouped, and the penetrating crack units do not participate in operation in the numerical simulation calculation process.
And (2) calculating in two steps, wherein the first step is to balance the ground stress of the model foundation part, and the second step is to calculate the self weight of the poured concrete on the basis of the balanced ground stress.
And (3) taking the X axis of a relation curve of characteristic points of the poured concrete dam heel and the dam site along with the river displacement, the vertical displacement and the vertical stress with the subsequent pouring process as the subsequent pouring times, taking the Y axis of the relation curve of the characteristic points of the poured concrete dam heel and the dam site along with the river displacement, the vertical displacement or the vertical stress, regarding the vertical stress of the poured concrete dam heel and the dam site in the subsequent pouring process, if the tensile stress is not allowed to appear at the poured concrete dam heel and the dam site in the subsequent pouring process, and after the stress concentration influence is deducted, the maximum compression stress value is less than or equal to the concrete compression static strength, the safety requirement is met, otherwise, the safety requirement is not met.
And (4) taking the X axis of a relation curve of characteristic points of the poured concrete dam heel and the dam site along with the river displacement, the vertical displacement and the vertical stress with the later stage water storage process as the later stage water storage process, taking the Y axis as the characteristic points of the poured concrete dam heel and the dam site along with the river displacement, the vertical displacement or the vertical stress, regarding the vertical stress of the poured concrete dam heel and the dam site in the later stage water storage process, allowing the tensile stress at the poured concrete dam heel in the later stage water storage process, but not allowing the tensile stress at the dam site, and after the stress concentration influence is deducted, satisfying the safety requirement if the maximum tensile stress value and the maximum compressive stress value are less than or equal to the static tensile strength and the static compressive strength of the concrete, or not satisfying the safety requirement.
Meanwhile, according to a finite element calculation result, the anti-skid stability safety coefficient between the poured concrete and the foundation and between the poured concrete and the newly poured concrete is solved by adopting the following formula, and the specific calculation formula is as follows:
in the formula, K' is the anti-skid stability safety coefficient calculated by the shear strength; f' is the friction coefficient of the contact surface against shear fracture; c' is the shearing and cohesion resistance of the contact surface; a is the sectional area of the contact surface; sigma W is a vertical value of all loads acting on the dam body to the sliding surface; sigma P is the value of the horizontal value of all the loads acting on the dam body to the river-direction on the sliding surface; n is the number of the gate chamber bottom plate nodes; w is aiThe vertical load borne by the ith node on the sliding surface is adopted; p is a radical ofiThe horizontal load along the river borne by the ith node on the sliding surface is adopted; i is a number and has a value ranging from 1 to n.
And if the anti-skid stability safety factor between the poured concrete and the foundation and between the poured concrete and the newly poured concrete is greater than the specified value of the specification, the integral stability of the poured concrete meets the safety requirement.
In the step (5), the X axis of a relation curve of node points at two sides of the crack along with the subsequent pouring process and the later stage water storage process is the subsequent pouring times and the later stage water storage process, the Y axis is the node points at two sides of the crack and the displacement along the river, the displacement along the vertical direction or the stress along the vertical direction, for the node points at two sides of the crack in the subsequent pouring process and the later stage water storage process, if the difference between the displacement along the river and the displacement along the vertical direction of the node points at two sides does not exceed 1 time of the width of the crack, the crack is judged not to be expanded, the safety requirement is met, otherwise, the crack width is judged to be expanded, the integral safety of the dam is influenced, and meanwhile, for the node points at two sides of the crack in the subsequent pouring process and the later stage water storage process, the tensile stress is not allowed to occur at the node points at two sides, and the maximum compressive stress values are less than or equal to the static compressive strength of the concrete, so that the safety requirement is met, otherwise, the safety requirement is not met.
And (4) if the judgment results of the steps (3) to (5) in the step (6) all meet the safety requirement, the quality of the poured concrete can meet the requirements of the subsequent pouring of the concrete and the water storage of the reservoir to each characteristic water level, and otherwise, the quality of the poured concrete cannot meet the requirements of the subsequent pouring of the concrete and the water storage of the reservoir to each characteristic water level.
Has the advantages that: according to the structural characteristics of the typical dam section of the roller compacted concrete gravity dam, a three-dimensional roller compacted concrete gravity dam finite element model is established, ADINA finite element analysis software is adopted, the influence of the subsequent concrete pouring process, the later stage water storage and the existence of cracks is considered, and the influence of the poured concrete on the dam forming safety is analyzed. The method can accurately simulate the influence of factors such as the subsequent concrete pouring process, the later stage water storage, the existence of cracks and the like on the poured concrete, and can provide corresponding basis and support for the subsequent concrete pouring and the later stage water storage.
Drawings
FIG. 1 is a front view of an integral three-dimensional finite element model of a 4# overflow dam section of a roller compacted concrete gravity dam;
FIG. 2 is an oblique view of an integral three-dimensional finite element model of a 4# overflow dam section of a certain roller compacted concrete gravity dam;
FIG. 3 is a three-dimensional finite element model front view of a dam body of a 4# overflow dam section of a roller compacted concrete gravity dam;
FIG. 4 is an oblique view of a three-dimensional finite element model of a dam body of a 4# overflow dam section of a roller compacted concrete gravity dam;
FIG. 5 shows a thin layer unit of poured concrete cracks of a 4# overflow dam section of a roller compacted concrete gravity dam;
FIG. 6 is a cloud picture (m) of displacement along the river under the action of the dead weight of the poured concrete;
FIG. 7 is a cloud (m) of vertical displacement of poured concrete under its own weight;
FIG. 8 is a cloud chart (Pa) of vertical stress under the action of the dead weight of the poured concrete;
FIG. 9 is a schematic view of a subsequent casting process of a 4# overflow dam section of a roller compacted concrete gravity dam;
FIG. 10 is a cloud (m) of the displacement of the poured concrete along the river after the fifteenth subsequent pouring;
FIG. 11 is a cloud (m) of vertical displacement of poured concrete after a fifteenth subsequent pour;
FIG. 12 is a vertical stress cloud (Pa) of poured concrete after a fifteenth subsequent pour;
FIG. 13 is a schematic diagram of the positions of the characteristic points of the poured concrete dam heel and the dam site;
FIG. 14 is a curve of the influence of the subsequent pouring process on the displacement along the river at the characteristic point A of the dam heel;
FIG. 15 is a curve of the effect of the subsequent pouring process on the displacement along the river at the characteristic point B of the dam heel;
FIG. 16 is a curve of the influence of the subsequent pouring process on the vertical displacement at the characteristic point A of the dam heel;
FIG. 17 is a curve of the influence of the subsequent casting process on the vertical displacement at the characteristic point B of the dam heel;
FIG. 18 is a curve of the influence of the subsequent pouring process on the vertical stress at the characteristic point A of the dam heel;
FIG. 19 is a curve showing the influence of the subsequent casting process on the vertical stress at the characteristic point B of the dam heel;
FIG. 20 is a schematic diagram of a vertical compressive stress exceeding area of a part of a dam heel after the concrete is poured for the fifteenth subsequent pouring;
FIG. 21 is a cloud (m) of the effect of impoundment to check water level on the displacement of poured concrete along the river;
FIG. 22 is a cloud (m) of the effect of impoundment to check water level on vertical displacement of poured concrete;
FIG. 23 is a cloud (Pa) of the effect of water storage to check water level on vertical stress of poured concrete;
FIG. 24 is a curve of the effect of the subsequent pouring process and the water storage to the check water level on the displacement along the river at the characteristic point A of the dam heel;
FIG. 25 is a curve of the effect of the subsequent pouring process and the water storage to the check water level on the displacement along the river at the characteristic point B of the dam heel;
FIG. 26 is a graph showing the effect of subsequent casting and impoundment to check water level on vertical displacement at the characteristic point A of the dam heel;
FIG. 27 is a graph showing the effect of subsequent casting and impoundment to check water level on vertical displacement at the feature point B of the dam heel;
FIG. 28 is a vertical stress influence curve of the dam heel characteristic point A in the subsequent pouring process and the effect of water storage to check water level;
FIG. 29 is a vertical stress influence curve of the dam heel characteristic point B in the subsequent pouring process and the effect of water storage to check water level;
FIG. 30 is a schematic diagram of the vertical stress exceeding area at the dam heel under the water storage to the check water level;
FIG. 31 is a schematic view of the location of each crush layer;
FIG. 32 is a curve showing the change of characteristic points of both sides of a crack in poured concrete along the direction of river displacement;
FIG. 33 is a vertical displacement variation curve of characteristic points at two sides of a crack of poured concrete;
FIG. 34 is a vertical stress variation curve of characteristic points on two sides of a crack of poured concrete.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
The roller compacted concrete gravity dam starts to be poured in the 9 th month in 2019, is poured to be 3m high in the 10 th middle month in 2019, and starts to carry out the overwintering heat preservation work in the 10 th middle month due to the fact that the hydro-junction project is displaced in a high-altitude high-cold area. In 4 months of 2020, a construction unit plans to continue to cast the dam on the basis of the cast concrete. In order to ensure the quality of poured concrete, the influence of the poured concrete of the roller compacted concrete gravity dam on the dam forming safety needs to be analyzed.
Establishing a three-dimensional finite element model of the overflow dam section according to the structural size of the roller compacted concrete gravity dam, wherein detailed structures such as a grouting gallery, a drainage gallery, an anti-seepage curtain and the like are considered in the model, and most of the model adopts eight-node hexahedral units for spatial dispersion; meanwhile, in order to simulate the subsequent construction process, the established models are layered and grouped; in addition, in order to consider the influence of the existence of cracks on the subsequent dam forming safety, a penetrating crack unit with the width of 1mm is preset in the model and is independently grouped, and the group of units do not participate in the operation in the numerical simulation calculation process, so that the purpose of simulating the cracks is achieved. The concrete model is shown in fig. 1-5.
The material parameters required by the numerical simulation calculation are shown in tables 1 and 2, and the engineering characteristic water level is shown in table 3.
TABLE 1 in-situ test parameters for poured concrete materials
Note: the concrete elastic modulus in the table is obtained by interpolation according to the compressive strength obtained by field detection and table 4.1.7 in the Hydraulic concrete structural design Specification (SL191-2008)
TABLE 2 concrete Material design parameters in subsequent casting Process
TABLE 3 characteristic Water level
Fig. 6-8 show the cloud images of the river displacement, vertical displacement and vertical stress of the poured concrete under the action of the self-weight when the subsequent concrete is not poured. It can be seen that when no subsequent pouring is performed, the displacement of the poured concrete along the river is basically 0, the value of the vertical displacement is smaller, and the vertical stress is mainly compressive stress.
Fig. 9 shows a schematic diagram of a subsequent pouring process, and fig. 10 to 12 respectively show cloud charts of the displacement along the river, the vertical displacement and the vertical stress of the poured concrete after the 15 th subsequent pouring. Meanwhile, for convenience of analysis, according to the distribution characteristics of the stress of the dam body of the gravity dam and the distribution characteristics of the displacement of the dam body, characteristic points a and B at two positions of the poured concrete dam heel and the dam site are selected, and are specifically shown in fig. 13.
Fig. 14-19 are the change curves of the dam heel characteristic point a and the dam site characteristic point B of the poured concrete part along the river displacement, the vertical displacement and the vertical stress in the subsequent pouring process respectively. It can be seen from the figure that along with the subsequent concrete pouring, the value of the displacement in the direction of the river at the dam heel and the dam site of the poured concrete part is gradually increased, but on the whole, the value of the displacement in the direction of the river at the dam heel and the dam site of the poured concrete part is smaller in the construction process, and the maximum value is less than 1 mm; along with the subsequent concrete pouring, the vertical displacement values of the dam heel and the dam site of the poured concrete part are gradually increased and are influenced by the gravity dam body type factor, and the vertical displacement at the dam heel is larger than that at the dam site; along with the subsequent concrete pouring, the vertical stress values at the dam heel and the dam site of the poured concrete part are gradually increased and are influenced by the gravity dam body type factor, the vertical stress at the dam heel is always in the increasing process, and the vertical stress at the dam site is gradually increased in speed and becomes stable in the later period.
In addition, as can be seen from fig. 18, the vertical stress at the dam heel exceeds the designed value of the C2825 concrete axial compressive strength during completion, on one hand, the range of the overproof area is extremely small, as shown in fig. 20 in particular; on the other hand, the position has obvious stress concentration phenomenon due to the fact that the geometrical shape changes suddenly, actually, the stress concentration phenomenon can be obviously relieved by the fine cracks of the rock body and the plastic deformation of the concrete, and the actual stress at the dam heel position is smaller than the result of finite element calculation. Therefore, as the subsequent concrete is poured, the vertical stress of the poured concrete meets the safety requirement.
For the influence of the later stage water storage process on the poured concrete, the space is limited, only the working condition calculation results from water storage to check water level are analyzed, and fig. 21 to 23 respectively show the cloud charts of the cast concrete along the river displacement, the vertical displacement and the vertical stress when the water storage is at the check water level. As can be seen from the figure, the cast concrete has downstream river-wise displacement under the action of front and rear water loads of the dam. For the whole dam body, under the action of water load, the displacement of the dam body along the river direction is gradually increased along with the increase of the elevation of the dam body, and reaches the maximum at the top of the dam, thereby conforming to the general rule; under the action of upstream and downstream water loads, the vertical displacement value of the poured concrete close to the upstream part is gradually reduced and is reduced to the minimum at the position of the dam heel, while the vertical displacement close to the downstream part is gradually increased and is increased to the maximum at the position of the dam, so that the general rule is met; along with the change of the water depth before and after the dam, the vertical stress of the poured concrete is basically compressive stress, only the dam heel is provided with a part of tensile stress area, and in addition, the vertical stress of the dam heel and the dam site has a stress concentration phenomenon because the geometrical shape has sudden change.
Fig. 24-29 are variation curves of the dam heel characteristic point a and the dam site characteristic point B of the poured concrete part along the river displacement, the vertical displacement and the vertical stress in the later stage water storage process. The dam heel and the dam site displacement along the river direction are obviously increased after water storage, and finally exceed the downstream direction along the direction of the river displacement under the action of water load; under the action of upstream and downstream water loads, the vertical displacement at the dam heel is obviously reduced, and the vertical displacement at the dam site is obviously increased; under the action of upstream and downstream water loads, the pressure stress at the characteristic point of the dam site is increased, the maximum pressure stress value is 12.86MPa and does not exceed C2825, the design value of the axial compressive strength of the concrete meets the safety requirement; the vertical stress at the characteristic point of the dam heel is converted from compression to tension, and the tensile stress value exceedsOver C2825 designed axial tensile strength of concrete. On one hand, the range of the over-standard tensile stress area at the dam heel is extremely small, and is particularly shown in figure 30; on the other hand, the position has obvious stress concentration phenomenon due to the fact that the geometrical shape changes suddenly, actually, the stress concentration phenomenon can be obviously relieved by the fine cracks of the rock body and the plastic deformation of the concrete, and the actual stress at the dam heel position is smaller than the result of finite element calculation.
For the safety factor of the anti-skid stability between the poured concrete and the foundation and the newly poured concrete, the following formula can be used:
in the formula: k' — the anti-skid stability safety factor calculated from the shear strength; f' -the contact surface has a shear-resistant friction coefficient; c' -the contact surface resists shear cohesion; a-contact surface cross section area; sigma W is the normal value of all loads acting on the dam body to the sliding surface; sigma P is the tangential component of all loads acting on the dam body to the sliding surface;
according to the finite element calculation result, the normal value and the tangential value between the foundation surface and each rolling layer can be obtained, and then the anti-skid stability safety coefficient between the foundation surface and each rolling layer can be obtained by adopting a shear strength formula. The crush layer position calculated this time is shown in fig. 31.
And the results of the analysis of the anti-skid stability among the overflow dam section base building surface, the 2515m elevation, the 2530m elevation and the 2557m elevation rolling layers are respectively shown in the tables 4 to 7. The table shows that the anti-sliding stability safety factors among the overflow dam section building base surface, the 2515m elevation, the 2530m elevation and the 2557m elevation rolling layers under different working conditions are all larger than the specification, and the safety requirements are met.
TABLE 4 summary table of analysis results of anti-skid stability of base surface of overflow dam section
TABLE 5 Overflow dam section 2515m elevation interlayer anti-skid stability analysis result summary table
TABLE 6 summary of anti-skid stability analysis results between 2530m elevation layers of overflow dam section
TABLE 7 summary table of anti-skid stability analysis results between 2557m elevation layers of overflow dam section
Fig. 32-34 show the displacement along the river, the vertical displacement and the change curve of the vertical stress of the characteristic points at two sides of the poured concrete crack in the subsequent pouring process and after the water is stored to the check water level. It can be seen that the characteristic points on the two sides of the crack basically do not generate relative displacement, that is, the width of the crack does not obviously change in the subsequent pouring process and the process from water storage to water level checking; along with the pouring of the subsequent concrete and the water storage to the checking water level in the later period, the vertical stress of the characteristic points on the two sides of the crack is compressive stress and does not exceed C 9015 designed axial compressive strength of concrete.
In summary, the poured concrete can meet the safety requirements in all aspects, and can meet the pouring of the subsequent concrete and the water storage of the reservoir to each characteristic water level. In addition, in the case of high water head, the existence of cracks is easy to cause the hydraulic fracture of concrete, and related treatment on the cracks is suggested for the safety of dam bodies.
Claims (7)
1. A method for judging the influence of poured concrete on dam forming safety is characterized by comprising the following steps:
(1) establishing a three-dimensional rolled concrete gravity dam finite element model according to the specific size of a typical dam section of the rolled concrete gravity dam, and layering and grouping the established model according to the subsequent construction process and the dam body material partition;
(2) inputting preset material parameters, boundary conditions and gravity loads based on ADINA finite element analysis software, and performing finite element dead weight calculation on the poured concrete to obtain displacement and stress of the poured concrete under the action of dead weight, wherein the displacement comprises river-wise displacement, transverse river-wise displacement and vertical displacement, and the stress comprises vertical stress, first principal stress and third principal stress;
(3) calculating to obtain displacement and stress of the poured concrete at different pouring elevations on the basis of the calculation result in the step (2), wherein the displacement comprises displacement along the river, displacement along the river and displacement along the vertical direction, and the stress comprises vertical stress, first principal stress and third principal stress, drawing a relation curve of characteristic points at the heel and the dam site of the poured concrete along the river, the vertical displacement and the vertical stress and a subsequent pouring process according to the calculation result, and judging the safety state of the poured part of concrete in the subsequent pouring process according to the relation curve of the stress at the heel and the dam site;
(4) on the basis of the calculation result of the step (3), considering the influences of dead weight load, water load, sediment load, uplift pressure and wave pressure under the combined action of different loads, calculating to obtain the displacement and stress of the poured concrete under the combined action of each load, wherein the displacement comprises displacement along the river, displacement along the transverse river and displacement along the vertical direction, and the stress comprises vertical stress, first principal stress and third principal stress, drawing the relation curves of characteristic points at the heel and the dam site of the poured concrete along the river, vertical displacement and vertical stress and the later stage water storage process according to the calculation result, judging the safety state of the poured part of concrete in the later stage water storage process according to the relation curves of the heel and the dam site, solving the anti-skid stability safety coefficient between the poured concrete and the foundation as well as the newly poured part of concrete, and comparing the calculated safety coefficient with the standard value, judging the stability of the poured concrete;
(5) according to the calculation result of the step (4), drawing a relation curve of node points at two sides of the crack to the downstream casting process and the later stage water storage process of the downstream casting process and the vertical direction stress, and judging the influence of the crack on the dam forming safety according to the node points at two sides of the crack to the displacement and stress relation;
(6) and (5) finally judging whether the poured concrete meets the dam-forming safety requirement or not according to whether the judgment results of the steps (3) to (5) meet the safety requirement or not.
2. The method for determining the influence of the poured concrete on the safety of the dam formation according to claim 1, wherein a grouting gallery, a drainage gallery and an anti-seepage curtain structure are considered in the three-dimensional roller compacted concrete gravity dam finite element model in the step (1), eight-node hexahedral units are adopted for spatial dispersion, 1 mm-wide penetrating crack units are preset in the model and are separately grouped, and the penetrating crack units do not participate in the operation in the numerical simulation calculation process.
3. The method for determining the influence of the cast concrete on the safety of the dam formation according to claim 1, wherein the calculation in the step (2) is performed in two steps, the first step is to perform ground stress balance on the model foundation part, and the second step is to perform self-weight calculation of the cast concrete on the basis of the ground stress balance.
4. The method for determining the influence of the poured concrete on the dam-forming safety according to claim 1, wherein an X axis of a relation curve between the characteristic points at the heel and the dam site of the poured concrete and the subsequent pouring process is the subsequent pouring times, a Y axis of the relation curve is the characteristic points at the heel and the dam site of the poured concrete and the river displacement, the vertical displacement or the vertical stress, for the vertical stress at the heel and the dam site of the poured concrete in the subsequent pouring process, the tensile stress is not allowed to appear at the heel and the dam site of the poured concrete in the subsequent pouring process, and after the stress concentration influence is deducted, the maximum compressive stress value is less than or equal to the static compressive strength of the concrete, so that the safety requirement is met, otherwise, the safety requirement is not met.
5. The method for determining the influence of the poured concrete on the safety of the formed dam according to claim 1, wherein the X-axis of the relation curve between the characteristic points at the heel and the dam site of the poured concrete and the later stage water storage process is the later stage water storage process, the Y-axis is the characteristic points at the heel and the dam site of the poured concrete and the later stage water storage process is the river displacement, the vertical displacement or the vertical stress, and for the vertical stress at the heel and the dam site of the poured concrete in the later stage water storage process, the tensile stress at the heel and the dam site of the poured concrete can be allowed to occur in the later stage water storage process, but the tensile stress at the dam site is not allowed to occur, and after the stress concentration influence is deducted, the maximum tensile stress value and the maximum compressive stress value are less than or equal to the static tensile strength and the static compressive strength of the concrete, so as to meet the safety requirement, otherwise the safety requirements are not met,
meanwhile, according to a finite element calculation result, the anti-skid stability safety coefficient between the poured concrete and the foundation and between the poured concrete and the newly poured concrete is solved by adopting the following formula, wherein the specific calculation formula is as follows:
in the formula, K' is the anti-skid stability safety coefficient calculated by the shear strength; f' is the friction coefficient of the contact surface against shear fracture; c' is the shearing and cohesion resistance of the contact surface; a is the sectional area of the contact surface; sigma W is the vertical value of all loads acting on the dam body to the sliding surface; sigma P is the value of the horizontal value of all the loads acting on the dam body to the river-direction on the sliding surface; n is the number of the gate chamber bottom plate nodes; w is aiThe vertical load borne by the ith node on the sliding surface is adopted; p is a radical ofiThe horizontal load along the river borne by the ith node on the sliding surface is adopted; i is a number, and the numeric area is 1 to n;
and if the anti-skid stability safety factor between the poured concrete and the foundation and between the poured concrete and the newly poured concrete is greater than the specified value of the specification, the integral stability of the poured concrete meets the safety requirement.
6. The method for determining the influence of the poured concrete on the safety of the dam according to claim 1, wherein in the step (5), the X-axis of the relation curve of the node points at two sides of the crack to the river displacement, the vertical displacement and the vertical stress in the subsequent pouring process and the later water storage process is the subsequent pouring times and the later water storage process, the Y-axis is the river displacement, the vertical displacement or the vertical stress of the node points at two sides of the crack in the subsequent pouring process and the later water storage process, if the difference between the river displacement and the vertical displacement of the node points at two sides of the crack in the subsequent pouring process and the later water storage process does not exceed 1 time of the width of the crack, the crack is determined not to be expanded, the safety requirement is met, otherwise, the crack width is determined to be expanded, the overall safety of the dam is affected, and meanwhile, the vertical stress of the node points at two sides of the crack in the subsequent pouring process and the later water storage process is determined, and the node points on the two sides do not allow tensile stress to appear, and the maximum compressive stress value is less than or equal to the static compressive strength of the concrete, so that the safety requirement is met, otherwise, the safety requirement is not met.
7. The method for determining the influence of the poured concrete on the dam-forming safety according to claim 1, wherein the determination results of the steps (3) to (5) in the step (6) all meet the safety requirement, so that the quality of the poured concrete can meet the requirements of the subsequent pouring of the concrete and the reservoir storage to the characteristic water levels, and otherwise, the pouring of the subsequent concrete and the reservoir storage to the characteristic water levels are not met.
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| JP2008115591A (en) * | 2006-11-02 | 2008-05-22 | Kenichi Hiraga | Concrete unit form sliding method, concrete unit form supporting fitting, concrete form fastening fitting, and lateral batten holding fitting |
| KR20130058135A (en) * | 2011-11-25 | 2013-06-04 | 지에스건설 주식회사 | Method for constructing face slab of concrete face rockfill dam using rail integrated side form |
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| CN109376429A (en) * | 2018-10-24 | 2019-02-22 | 中国水利水电第七工程局有限公司 | A kind of concrete dam template safe construction analysis method based on finite element simulation |
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| JP2008115591A (en) * | 2006-11-02 | 2008-05-22 | Kenichi Hiraga | Concrete unit form sliding method, concrete unit form supporting fitting, concrete form fastening fitting, and lateral batten holding fitting |
| KR20130058135A (en) * | 2011-11-25 | 2013-06-04 | 지에스건설 주식회사 | Method for constructing face slab of concrete face rockfill dam using rail integrated side form |
| CN105574250A (en) * | 2015-12-15 | 2016-05-11 | 中国电建集团中南勘测设计研究院有限公司 | Concrete material partition design method |
| CN109376429A (en) * | 2018-10-24 | 2019-02-22 | 中国水利水电第七工程局有限公司 | A kind of concrete dam template safe construction analysis method based on finite element simulation |
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