CN112446079B - Method for judging influence of poured concrete on dam safety - Google Patents
Method for judging influence of poured concrete on dam safety Download PDFInfo
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Abstract
The invention discloses a method for judging influence of poured concrete on dam safety, which establishes a three-dimensional roller compacted concrete gravity dam finite element model according to the structural characteristics of a typical dam section of the roller compacted concrete gravity dam, adopts ADINA finite element analysis software, considers influence of a subsequent concrete pouring process, later water storage and crack existence, and analyzes influence of the poured concrete on dam safety. The invention provides a method for analyzing the influence of poured concrete of a roller compacted concrete gravity dam on dam safety, which can accurately simulate the influence of factors such as a follow-up 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 follow-up concrete pouring and later-stage water storage.
Description
Technical Field
The invention relates to a method for judging the safety of a roller compacted concrete gravity dam, in particular to a method for judging the influence of poured concrete on the safety of the dam.
Background
Roller compacted concrete gravity dam is a new dam construction technology which has been developed faster in the eighties of the twentieth century, and is favored by dam industry due to the characteristics of rapidness and economy. At present, the related research on the influence of factors such as the follow-up pouring process, the later water storage, the existence of cracks and the like on the quality of poured roller compacted concrete is less, and the problem is just the concern in the engineering construction process. Therefore, in order to ensure the successful 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 later water storage, the existence of cracks and the like on the poured roller compacted concrete.
Disclosure of Invention
The invention aims to: the invention aims to provide a method for judging the influence of poured concrete on dam safety, and solves the problem that no method for judging the influence of poured concrete on dam safety exists at present.
The technical scheme is as follows: the method for judging the influence of poured concrete on dam safety comprises the following steps:
(1) Establishing a three-dimensional roller compacted concrete gravity dam finite element model according to the specific size of a typical dam section of the roller compacted concrete gravity dam, and layering and grouping the established model according to the follow-up construction process and dam material partition;
(2) Based on ADINA finite element analysis software, inputting preset material parameters, boundary conditions and gravity load, and carrying out finite element dead weight calculation on the poured concrete to obtain displacement and stress of the poured concrete under the dead weight effect, wherein the displacement comprises river-direction displacement, horizontal river-direction displacement and vertical displacement, and the stress comprises vertical stress, first main stress and third main stress;
(3) Calculating 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 along-river displacement, transverse-river displacement and vertical displacement, the stress comprises vertical stress, first main stress and third main stress, a relation curve of along-river displacement, vertical displacement and vertical stress of characteristic points at the positions of the poured concrete heel and the dam site and a subsequent pouring process is drawn according to the calculation result, and the safety state of the poured concrete in the subsequent pouring process is judged according to the stress relation curve at the positions of the heel and the dam site;
(4) On the basis of the calculation result of the step (3), aiming at working conditions in different water storage periods, considering the influences of dead weight load, water load, sediment load, lifting force and wave pressure, calculating to obtain displacement and stress of the poured concrete under the combined action of all loads, wherein the displacement comprises along-river displacement, transverse-river displacement and vertical displacement, the stress comprises vertical stress, first main stress and third main stress, drawing relation curves of characteristic points along-river displacement, vertical stress and a later water storage process at the positions of a poured concrete dam heel and a dam site according to the calculation result, judging the safety state of the poured concrete in the later water storage process according to the stress relation curves at the positions of the dam heel and the dam site, solving the anti-slip stable safety coefficient between the poured concrete and the foundation and the concrete in the new poured part, comparing the calculated safety coefficient with a standard 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 on the forward displacement, the vertical displacement and the vertical stress, and then the continuous casting process and the later water storage process, and judging the influence of the crack on the dam formation safety according to the relation of the node points at two sides of the crack on the displacement and the stress;
(6) And (3) finally judging whether the poured concrete meets the dam forming safety requirement according to the judging results of the steps (3) - (5) whether the safety requirements are met.
In the step (1), a grouting gallery, a drainage gallery and an impermeable curtain structure are considered in a three-dimensional roller compacted concrete gravity dam finite element model, eight-node hexahedral units are adopted for space dispersion, penetrating crack units with the width of 1mm are preset in the model, the penetrating crack units are separately grouped, and the penetrating crack units do not participate in operation in the numerical simulation calculation process.
The calculation in the step (2) is carried out in two steps, wherein the first step is to perform ground stress balance on the model foundation part, and the second step is to perform the dead weight calculation of the poured concrete on the basis of the ground stress balance.
And (3) taking the X axis of a relation curve of the river-direction displacement, the vertical displacement and the vertical stress of the feature points at the poured concrete dam heel and the dam site in the step (3) as the subsequent pouring times, taking the Y axis as the river-direction displacement, the vertical displacement or the vertical stress of the feature points at the poured concrete dam heel and the dam site in the subsequent pouring process, and taking the maximum compressive stress value smaller than or equal to the static compressive strength of the concrete after the influence of stress concentration is deducted, wherein the maximum compressive stress value is smaller than or equal to the safety requirement, and otherwise, the safety requirement is not satisfied.
And (3) in the step (4), the X axis of the relation curve of the characteristic points of the poured concrete heel and the dam site along the river, the vertical displacement and the vertical stress and the post water storage process is the post water storage process, the Y axis is the characteristic points of the poured concrete heel and the dam site along the river, the vertical displacement or the vertical stress, and for the vertical stress of the poured concrete heel and the dam site in the post water storage process, the tensile stress is allowed to appear at the poured concrete heel in the post water storage process, but the tensile stress is not allowed to appear at the dam site, and after the influence of stress concentration is subtracted, the maximum tensile stress value and the maximum compressive stress value are smaller than or equal to the static tensile strength and the static compressive strength of the concrete, so that the safety requirement is met, otherwise, the safety requirement is not met.
Meanwhile, according to the finite element calculation result, solving the anti-slip stable safety coefficient between the poured concrete and the foundation and between the poured concrete and the newly poured concrete by adopting the following formula, wherein the concrete calculation formula is as follows:
wherein K' is an anti-slip stable safety coefficient calculated by the anti-shear strength; f' is the shearing resistance friction coefficient of the contact surface; c' is the shearing-resistant cohesive force of the contact surface; a is the cross section of the contact surface; sigma W is the vertical score of all loads acting on the dam body on the sliding surface; Σp is the horizontal value of the parallel river on the sliding surface for all loads acting on the dam body; n is the number of the bottom plate nodes of the lock chamber; w (w) i The vertical load is applied to the ith node on the sliding surface; p is p i The horizontal load of the river direction born by the ith node on the sliding surface; i is a number, and the value range is 1 to n.
And if the anti-slip stability safety coefficient between the poured concrete and the foundation and between the poured concrete and the newly poured concrete are larger than the standard specified value, the overall stability of the poured concrete meets the safety requirement.
And (3) in the step (5), the X axis of the relation curve of the crack two-side node point pair along 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 crack two-side node point pair along the river displacement, the vertical displacement or the vertical stress, for the crack two-side node point pair along the river displacement and the vertical displacement in the subsequent pouring process and the later water storage process, if the crack two-side node point pair along the river displacement and the vertical displacement difference is not more than 1 time of the crack width, 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, meanwhile, for the crack two-side node point pair vertical stress in the subsequent pouring process and the later water storage process, the tensile stress is not allowed to appear, and the maximum compressive stress value is less than or equal to the concrete static compressive strength, otherwise, the safety requirement is not met.
And (3) in the step (6), the judging results of the steps (3) - (5) meet the safety requirements, the quality of the poured concrete can meet the requirements of pouring the subsequent concrete and storing water in the reservoir to each characteristic water level, and otherwise, the quality of the poured concrete cannot meet the requirements of pouring the subsequent concrete and storing water in the reservoir to each characteristic water level.
The beneficial effects are that: according to the structural characteristics of a 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 follow-up concrete pouring process, the later-stage water storage and the existence of cracks is considered, and the influence of poured concrete on dam formation safety is analyzed. The invention can more accurately simulate the influence of factors such as the follow-up 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 follow-up 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 overall three-dimensional finite element model of a 4# overflow dam segment of a roller compacted concrete gravity dam;
FIG. 3 is a front view of a three-dimensional finite element model of a 4# overflow dam segment of a roller compacted concrete gravity dam;
FIG. 4 is an oblique view of a three-dimensional finite element model of a 4# overflow dam segment of a roller compacted concrete gravity dam;
FIG. 5 is a thin layer unit of poured concrete cracks for a 4# overflow dam segment of a roller compacted concrete gravity dam;
FIG. 6 is a cloud image (m) of the displacement of a river under the dead weight of poured concrete;
FIG. 7 is a vertical displacement cloud image (m) under the weight of the poured concrete;
FIG. 8 is a vertical stress cloud (Pa) under the weight of the poured concrete;
fig. 9 is a schematic diagram of a subsequent pouring process of a 4# overflow dam section of a roller compacted concrete gravity dam;
FIG. 10 is a downstream movement cloud image (m) of the poured concrete along the river after the fifteenth pouring;
FIG. 11 is a vertical displacement cloud image (m) of the poured concrete after the fifteenth pouring;
FIG. 12 is a vertical stress cloud (Pa) of the poured concrete after a fifteenth subsequent pouring;
FIG. 13 is a schematic view of the placement of a poured concrete heel and site feature points;
FIG. 14 is a plot of influence of the subsequent casting process on the forward river displacement at the heel feature point A;
FIG. 15 is a plot of influence of the subsequent casting process on the forward river displacement at the heel feature point B;
FIG. 16 is a graph of the influence of the subsequent casting process on vertical displacement at the dam heel feature point A;
FIG. 17 is a graph showing the influence of the subsequent casting process on the vertical displacement at the characteristic point B of the dam heel;
FIG. 18 is a graph showing the effect of subsequent casting on vertical stress at feature point A of the dam heel;
FIG. 19 is a graph showing the effect of subsequent casting on vertical stress at the dam heel feature point B;
FIG. 20 is a schematic view of a vertical compressive stress overstocked area of a poured concrete portion dam heel after a fifteenth subsequent pour;
FIG. 21 is a cloud image (m) of the influence of impounded water to check water level on the displacement of poured concrete along the river;
FIG. 22 is a cloud image (m) of the vertical displacement of poured concrete affected by the impounded water to a check water level;
FIG. 23 is a cloud graph (Pa) of the vertical stress effect of the impounded water to the check water level on the poured concrete;
FIG. 24 is a graph showing the influence of the subsequent casting process and water accumulation to check the water level on the displacement of the along river at the characteristic point A of the dam heel;
FIG. 25 is a graph showing the influence of the subsequent casting process and water accumulation to check the water level on the displacement of the river at the characteristic point B of the dam heel;
FIG. 26 is a graph showing the influence of the subsequent casting process and the impounded water level to check the vertical displacement at the dam heel feature point A;
FIG. 27 is a graph showing the influence of the subsequent casting process and the water accumulation to the check water level on the vertical displacement at the characteristic point B of the dam heel;
FIG. 28 is a graph showing the influence of the subsequent casting process and the water accumulation to the check water level on the vertical stress at the characteristic point A of the dam heel;
FIG. 29 is a graph showing the influence of the subsequent casting process and the impounded water level to check the vertical stress at the dam heel feature point B;
FIG. 30 is a schematic view of a vertical stress overscale region from impounded water to a check level lower dam heel;
FIG. 31 is a schematic view of the positions of the rolling layers;
FIG. 32 is a plot of the variation of the river displacement of the characteristic points on both sides of a poured concrete crack;
FIG. 33 is a graph of vertical displacement change of feature points on both sides of a poured concrete crack;
FIG. 34 is a graph of vertical stress variation of feature points on both sides of a poured concrete crack.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
And pouring a certain roller compacted concrete gravity dam in the 9 th month of 2019, and pouring the roller compacted concrete gravity dam to the height of 3m in the 10 th month of 2019, wherein the water conservancy junction engineering is displaced in the high-altitude high-severe cold region, and the winter heat preservation work of the dam is started in the middle and the last 10 th months. And 4 months in 2020, the construction unit plans to continue pouring the dam on the basis of the poured concrete. To ensure the quality of the poured concrete, it is necessary to analyze the impact of the rolled concrete gravity dam poured concrete on the safety of the dam.
According to the structural size of the roller compacted concrete gravity dam, a three-dimensional finite element model of an overflow dam section is established, wherein the model considers the detailed structures of a grouting gallery, a drainage gallery, an anti-seepage curtain and the like, and most of the model adopts an eight-node hexahedral unit for space dispersion; meanwhile, layering and grouping the built model for simulating the subsequent construction process; in addition, in order to consider the influence of the existence of cracks on the safety of the subsequent dam formation, penetrating crack units with the width of 1mm are preset in a model, and are individually grouped, and in the numerical simulation calculation process, the group of units do not participate in calculation, so that the purpose of simulating the cracks is achieved. The specific model is shown in fig. 1-5.
The parameters of the materials required by the numerical simulation calculation are shown in tables 1 and 2, and the characteristic water level of the engineering is shown in table 3.
TABLE 1 in situ detection parameters of poured concrete materials
Note that: the elastic modulus of the concrete in the table is the compressive strength obtained according to the field detection and is obtained by combining the interpolation of table 4.1.7 in the design Specification of Hydraulic concrete Structure (SL 191-2008)
TABLE 2 concrete material design parameters during subsequent casting
TABLE 3 characteristic water levels
Fig. 6-8 show the river displacement, vertical displacement and vertical stress cloud patterns of the poured concrete under the action of dead weight when the following concrete is not poured. It can be seen that when the subsequent pouring is not performed, the displacement of the poured concrete along the river is basically 0, the vertical displacement value is also smaller, and the vertical stress is mainly compressive stress.
Fig. 9 shows a schematic diagram of a subsequent casting process, and fig. 10 to 12 show along-river displacement, vertical displacement and vertical stress cloud diagrams of the cast concrete after the 15 th casting process. Meanwhile, for the convenience of analysis, according to the distribution characteristics of the stress of the gravity dam body and the distribution characteristics of the displacement of the dam body, characteristic points A and B of two positions of the poured concrete dam heel and the dam site are selected, and the characteristic points A and B are specifically shown in fig. 13.
Fig. 14-19 are graphs showing the variation of the directional displacement, vertical displacement and vertical stress of the dam heel feature point a and the dam site feature point B of the poured concrete site along the river, respectively, and the subsequent pouring process. As can be seen from the figure, along with the subsequent concrete pouring, the numerical value of the forward displacement of the poured concrete site dam heel and the dam site is gradually increased, but the numerical value of the forward displacement of the poured concrete site dam heel and the dam site is smaller in the construction process, and the maximum value is less than 1mm; along with the pouring of the follow-up concrete, the vertical displacement values of the dam heel and the dam site of the poured concrete part are gradually increased, and the vertical displacement of the dam heel is larger than the vertical displacement of the dam site under the influence of gravity dam body factors; along with the subsequent concrete pouring, the vertical stress 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 factors, the vertical stress of the dam heel is always in the increasing process, and the vertical stress of the dam site is gradually increased and gradually slowed down and becomes stable in the later period.
In addition, as can be seen from fig. 18, the vertical stress at the dam heel during completion period exceeds the designed compressive strength of the concrete axis of C2825, on the one hand, the exceeding area is extremely small, as shown in fig. 20; on the other hand, the position has obvious stress concentration phenomenon due to abrupt change of geometric shapes, and in fact, the micro cracks of the rock mass and the shaping deformation of the concrete can play a remarkable role in relieving the stress concentration phenomenon, and the actual stress at the dam heel is smaller than the result of finite element calculation. Thus, with subsequent concrete placement, the vertical stress of the poured concrete meets the safety requirements.
For the influence of the later water storage process on the poured concrete, the calculation result of the working condition from water storage to check water level is only analyzed, and fig. 21-23 respectively show the along-river displacement, the vertical displacement and the vertical stress cloud pictures of the poured concrete when the water storage is up to the check water level. As can be seen from the figure, the poured concrete is displaced downstream in the river under the action of the water load before and after the dam. For the whole dam body, under the action of water load, the displacement of the dam body along the river gradually increases along with the increase of the height of the dam body, reaches the maximum at the top of the dam, and accords with the general rule; under the effect of the load of the upstream water and the downstream water, the vertical displacement value of the poured concrete near the upstream part is gradually reduced to the minimum at the dam heel, and the vertical displacement of the poured concrete near the downstream part is gradually increased to the maximum at the dam site, so that the concrete meets the general rule; along with the change of the depth of water in front of the dam and behind the dam, the vertical stress of the poured concrete is basically compressive stress, only partial tensile stress areas exist at the positions of the dam butts, and in addition, the phenomenon of stress concentration occurs at the positions of the dam butts and the dam sites due to abrupt change of the geometric shapes.
FIGS. 24-29 are graphs showing the change in the course of the subsequent impoundment of water in the river-wise displacement, vertical displacement and vertical stress of the poured concrete site at the dam heel feature point A and the dam site feature point B, respectively. It can be seen that the displacement along the river of the dam heel and the dam site after water storage is obviously increased, and the displacement along the river finally exceeds the downstream direction under the action of water load; under the action of upstream and downstream water loads, the vertical displacement of the dam heel is obviously reduced, and the vertical displacement of the dam site is obviously increased; under the load of the upstream and downstream water, the compressive stress at the dam site characteristic point is increased, the maximum compressive stress value is 12.86MPa, and the maximum compressive stress value does not exceed C 28 25. The design value of the compressive strength of the concrete axle center meets the safety requirement; the vertical stress at the characteristic points of the dam heel is changed from compression to tension, and the tensile stress value exceeds C 28 25 concrete axial tensile strength design value. However, on the one hand, the range of the tensile stress exceeding area at the dam heel is extremely small, and the range is particularly shown in fig. 30; on the other hand, the position has obvious stress concentration phenomenon due to abrupt change of geometric shapes, and in fact, both the microcrack of the rock mass and the shaping deformation of the concrete can play a remarkable role in relieving the stress concentration phenomenon, and the actual stress at the dam heel is smaller than the result of finite element calculation.
For the anti-slip stable safety coefficient between the poured concrete and the foundation and the newly poured part concrete, the following formula can be adopted:
wherein: k' — anti-slip stable safety coefficient calculated by the anti-shear strength; f' — the contact surface gives a shear friction coefficient; c' — shearing resistant cohesive force of the contact surface; a-the cross-sectional area of the contact surface; Σw—normal score on the sliding surface for the full load on the dam; Σp—tangential component of the total load acting on the dam against the sliding surface;
according to the finite element calculation result, the normal score and the tangential score between the building base surface and each rolling layer can be obtained, and then the anti-slip stable safety coefficient between the building base surface and each rolling layer can be obtained by adopting a shearing strength formula. The position of the rolling layer calculated at this time is shown in fig. 31.
Tables 4-7 show the results of the anti-slip stability analysis between the overflow dam segment base, 2515m elevation, 2530m elevation and 2557m Gao Chengnian bearing, respectively. As shown in the table, the anti-slip stable safety coefficients among the overflow dam section building base surface, 2515m elevation, 2530m elevation and 2557m elevation rolling layers under different working conditions are all larger than the standard specification, and the safety requirements are met.
TABLE 4 anti-slip stability analysis results summary table for overflow dam segment building base
TABLE 5 Overflow dam segment 2515m elevation interlayer anti-skid stability analysis results summary table
TABLE 6 Overflow dam segment 2530m elevation interlayer anti-skid stability analysis results summary table
TABLE 7 results summary of anti-skid stability analysis between 2557m elevations of overflow dam segments
FIGS. 32-34 illustrate the subsequent casting, respectivelyAnd (3) after the process and water storage are carried out to check the water level, the characteristic points on the two sides of the poured concrete crack are displaced along the river, vertically displaced and vertically stressed change curve. It can be seen that the characteristic points on the two sides of the crack basically do not generate relative displacement, namely the width of the crack does not generate obvious change in the subsequent pouring process and the process of storing water to check the water level; along with the casting of the follow-up concrete and the later water storage to the check water level, the vertical stress of the characteristic points at the two sides of the crack is compressive stress and does not exceed C 90 15 concrete axle center compressive strength design value.
In summary, the poured concrete meets the safety requirements in all aspects, and can meet the requirements of the subsequent pouring of the concrete and the water storage of the reservoir to all characteristic water levels. In addition, under the condition of high water head, the existence of the crack is easy to cause hydraulic fracture of the concrete, and the related treatment of the crack is recommended for the safety of the dam body.
Claims (7)
1. The method for judging the influence of the poured concrete on the safety of the dam is characterized by comprising the following steps of:
(1) Establishing a three-dimensional roller compacted concrete gravity dam finite element model according to the specific size of a typical dam section of the roller compacted concrete gravity dam, and layering and grouping the established model according to the follow-up construction process and dam material partition;
(2) Based on ADINA finite element analysis software, inputting preset material parameters, boundary conditions and gravity load, and carrying out finite element dead weight calculation on the poured concrete to obtain displacement and stress of the poured concrete under the dead weight action, wherein the displacement comprises river-direction displacement, horizontal river-direction displacement and vertical displacement, and the stress comprises vertical stress, first main stress and third main stress;
(3) Calculating the 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 along-river displacement, transverse-river displacement and vertical displacement, the stress comprises vertical stress, first main stress and third main stress, the relation curve of the along-river displacement, the vertical stress and the subsequent pouring process of the feature points at the positions of the poured concrete dam heels and the dam sites is drawn according to the calculation result, and the safety state of the poured concrete in the subsequent pouring process is judged according to the stress relation curve at the positions of the dam heels and the dam sites;
(4) On the basis of the calculation result of the step (3), aiming at working conditions in different water storage periods, considering the influences of dead weight load, water load, sediment load, lifting force and wave pressure, calculating to obtain displacement and stress of the poured concrete under the combined action of all loads, wherein the displacement comprises parallel-river displacement, transverse-river displacement and vertical displacement, the stress comprises vertical stress, first main stress and third main stress, drawing relation curves of characteristic points at the positions of the poured concrete heel and the dam site in the parallel-river displacement, vertical displacement and vertical stress and a later water storage process according to the calculation result, judging the safety state of the poured concrete in the later water storage process according to the relation curves of the characteristic points at the positions of the dam heel and the dam site, solving the anti-slip stable safety coefficient between the poured concrete and the foundation and the concrete in the new poured part, comparing the calculated safety coefficient with a standard 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 on the forward displacement, the vertical displacement and the vertical stress, then the continuous casting process and the later water storage process, and judging the influence of the crack on the dam formation safety according to the node point displacement and the stress relation at two sides of the crack;
(6) And (3) finally judging whether the poured concrete meets the dam forming safety requirement according to the judging results of the steps (3) - (5) whether the safety requirements are met.
2. The method for determining the influence of poured concrete on dam safety according to claim 1, wherein in the step (1), the grouting gallery, the drainage gallery and the impervious curtain structure are considered in a three-dimensional roller compacted concrete gravity dam finite element model, the eight-node hexahedral units are adopted for space dispersion, penetrating crack units with the width of 1mm are preset in the model, the penetrating crack units are separately grouped, and the penetrating crack units do not participate in operation in the numerical simulation calculation process.
3. The method for determining the influence of poured concrete on dam safety according to claim 1, wherein the calculation in the step (2) is performed in two steps, the first step is to perform the ground stress balance on the model foundation portion, and the second step is to perform the calculation of the self weight of the poured concrete on the basis of the ground stress balance.
4. The method for determining the influence of the poured concrete on the dam formation safety according to claim 1, wherein in the step (3), the X axis of the relationship curve of the characteristic points along the river direction displacement, the vertical direction displacement and the vertical direction stress at the poured concrete dam heel and the dam site is the subsequent pouring times, the Y axis is the characteristic points along the river direction displacement, the vertical direction displacement or the vertical direction stress at the poured concrete dam heel and the dam site, the vertical stress at the poured concrete dam heel and the dam site in the subsequent pouring processes is not allowed, the maximum compressive stress value is smaller than or equal to the static compressive strength of the concrete after the influence of stress concentration is subtracted, the safety requirement is met, and otherwise the safety requirement is not met.
5. The method according to claim 1, wherein the X-axis of the relationship curve of the characteristic points along river displacement, vertical displacement and vertical stress at the poured concrete heel and the dam site in the step (4) is the post-water storage process, the Y-axis is the characteristic points along river displacement, vertical displacement or vertical stress at the poured concrete heel and the dam site in the post-water storage process, for the vertical stress at the poured concrete heel and the dam site in the post-water storage process, the tensile stress is allowed to occur at the poured concrete heel and the dam site in the post-water storage process, but the tensile stress is not allowed to occur at the dam site, and after the influence of the stress concentration is subtracted, 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 that the safety requirement is satisfied, otherwise, the safety requirement is not satisfied,
meanwhile, according to the finite element calculation result, solving the anti-slip stable safety coefficient between the poured concrete and the foundation and between the poured concrete and the newly poured concrete by adopting the following formula:
wherein K' is an anti-slip stable safety coefficient calculated by the anti-shear strength; f' is the shearing resistance friction coefficient of the contact surface; c' is the shearing-resistant cohesive force of the contact surface; a is the cross section of the contact surface; sigma W is the vertical score of all loads acting on the dam body on the sliding surface; Σp is the horizontal value of the parallel river on the sliding surface for all loads acting on the dam body; n is the number of the bottom plate nodes of the lock chamber; w (w) i The vertical load is applied to the ith node on the sliding surface; p is p i The horizontal load of the river direction born by the ith node on the sliding surface; i is a number, and the value range is 1 to n;
and if the anti-slip stability safety coefficient between the poured concrete and the foundation and between the poured concrete and the newly poured concrete are larger than the standard specified value, the overall stability of the poured concrete meets the safety requirement.
6. The method for determining the influence of the poured concrete on the dam safety according to claim 1, wherein the X-axis of the relationship curve of the crack two-side node point pair along the river displacement, the vertical displacement and the vertical stress in the step (5) is the subsequent pouring times and the subsequent water storage process, the Y-axis is the crack two-side node point pair along the river displacement, the vertical displacement or the vertical stress, and for the subsequent pouring process and the subsequent water storage process, the crack two-side node point pair along the river displacement and the vertical displacement are determined not to expand if the difference between the crack two-side node point pair along the river displacement and the vertical displacement is not more than 1 time of the crack width, so as to meet the safety requirement, otherwise, the crack width is determined to expand, so that the integral safety of the dam is affected, meanwhile, the tensile stress is not allowed to occur at the crack two-side node point pairs in the subsequent pouring process and the subsequent water storage process, and the maximum compressive stress value is less than or equal to the static compressive strength of the concrete, so as to meet the safety requirement, otherwise, the safety requirement is not met.
7. The method according to claim 1, wherein the determination results of steps (3) - (5) in step (6) meet the safety requirement, and the quality of the poured concrete can meet the requirements of pouring the subsequent concrete and storing the water in the reservoir to the characteristic water levels, and otherwise, the method does not meet the requirements of pouring the subsequent concrete and storing the water in the reservoir to the characteristic water levels.
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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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