Method for setting effective depth of shock isolation trench
By measuring acceleration on-site and adjusting the depth of the isolation trench at monitoring points, combined with linear slope finding technology, the problem of uncertain isolation trench depth was solved, achieving an economical and efficient vibration isolation effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WUHAN SURVEYING GEOTECHN RES INST OF MCC
- Filing Date
- 2024-02-05
- Publication Date
- 2026-04-28
AI Technical Summary
The lack of specific methods for determining the excavation depth of existing seismic isolation trenches leads to increased workload and material waste, or the inability to effectively block the propagation of vibrations, affecting the surrounding environment and building safety.
By measuring acceleration in the field, the effective depth of the seismic isolation trench at different locations is determined. Acceleration is monitored in real time using monitoring points, and the depth of the seismic isolation trench is dynamically adjusted to ensure that safety control standards are met. The trench depth is optimized by combining linear slope finding technology.
This approach effectively reduces construction costs, blocks vibration propagation, protects the surrounding environment and building safety, and minimizes earthwork excavation.
Smart Images
Figure CN118029566B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of seismic isolation technology in geotechnical engineering construction, specifically to a method for setting the effective depth of a seismic isolation trench. Background Technology
[0002] During construction, blasting, pile driving, dynamic compaction of foundations, vehicle vibrations, and subway vibrations all generate enormous amounts of energy. A portion of this energy is converted into stress waves, which primarily manifest as seismic waves. These seismic waves propagate from the compaction point outwards, causing ground vibrations. These vibrations lead to uneven settlement of the surrounding soil, resulting in varying degrees of damage to the surrounding environment, residents, buildings, and underground pipelines. This severely impacts the normal lives of nearby residents and can also adversely affect precision instruments installed nearby.
[0003] To reduce the adverse impact of construction vibrations on the surrounding environment and residents, seismic isolation trenches of a certain depth and width are typically constructed between the construction site and the protected targets. Currently, there is no specific method for determining the excavation depth of these trenches. Generally, the trench depth remains constant along its length during construction. However, the intensity of vibrations is positively correlated with the distance from the seismic source; locations farther from the source do not necessarily require the same trench depth as those closer. Excavating all trenches to the maximum required depth would result in unnecessary increases in workload and waste of building materials. Conversely, failing to excavate to the maximum required depth would not achieve the desired seismic isolation effect. Summary of the Invention
[0004] To address the shortcomings of the existing technology, this invention provides a method for setting the effective depth of a seismic isolation trench. By measuring the magnitude of acceleration on-site, the effective depth of the seismic isolation trench at different locations that meets the vibration requirements can be determined, which can both ensure the seismic isolation effect and reduce construction costs.
[0005] To achieve the above technical objectives, the present invention provides a method for setting the effective depth of a seismic isolation trench, characterized by the following steps:
[0006] S1. A seismic isolation trench shall be installed between the seismic source area and the existing buildings and structures, with a width of 0.5 to 2m;
[0007] S2. Determine the seismic fortification intensity and corresponding standard horizontal acceleration a of the area where the vibration source and existing buildings and structures are located. x控 and standard vertical acceleration a y控 This refers to the safety control standards for buildings and structures.
[0008] S3. Connect the two endpoints A and D of the boundary line of the area adjacent to the existing building to each corner of the outer contour of the existing building. The area between the two outermost lines is the vibration influence range. The length of the seismic isolation trench exceeds the vibration influence range by at least 3m.
[0009] S4. Set up monitoring points at each corner of the outer contour of the existing building to monitor the vertical and horizontal acceleration at each corner of the outer contour of the existing building in real time.
[0010] S5. The initial depth of the seismic isolation trench is set to h0, the foundation depth of the existing building structure, and the seismic isolation trench is excavated according to the initial depth h0;
[0011] S6. After the initial excavation of the seismic isolation trench is completed, the vibration source is controlled to move along the edge of the area adjacent to the existing building within the vibration source range. During the movement, the measured horizontal acceleration 'a' at each corner of the outer contour of the existing building is monitored through the monitoring points set up in step S4 when the vibration source moves to each position. x测 And the measured vertical acceleration a y测 And by comparing the measured horizontal acceleration a x测 And the measured vertical acceleration a y测 Compared with the standard horizontal acceleration a in step S2 x控 and standard vertical acceleration a y控 The size of the trough determines whether its depth meets the requirements.
[0012] When a at each monitoring point x测 ≤a x控 And a y测 ≤a y控 Then, the excavation depth of the isolation trench corresponding to the horizontal direction of the vibration source location is the effective depth.
[0013] If during the movement, the measured horizontal acceleration 'a' at each monitoring point... x测 And the measured vertical acceleration a y测 If the above requirements are not met, the depth of the isolation trench corresponding to the horizontal direction of the vibration source location is insufficient for the effective depth. The depth of the isolation trench in this area needs to be increased until the required depth for each monitoring point (a) is met. x测 ≤a x控 And a y测 ≤a y控 At this point, the depth of the seismic isolation trench is the effective depth.
[0014] A further technical solution of the present invention: In step S6, the vibration source is controlled to move along the edge of the area adjacent to the existing building within the vibration source range, and the measured horizontal acceleration α at each corner of the outer contour line of the existing building is monitored during the movement. x测And the measured vertical acceleration a y测 The specific process for determining whether the depth of the seismic isolation trench meets the requirements is as follows:
[0015] (1) Connect the corner point closest to the edge line of the existing building's outer contour line to point A on the side of the existing building adjacent to the seismic source range with point A. Set the intersection of this line with the seismic isolation trench as point a, and set the endpoint of the seismic isolation trench adjacent to point a as point a0. Connect the two corner points closest to the edge line of the existing building's outer contour line to the side of the existing building adjacent to the seismic source range with horizontal lines respectively. Set the positions of the horizontal lines to the edge line of the area as points B and C respectively, and set the intersections of the two horizontal lines with the seismic isolation trench as points b and c respectively. Connect the corner point closest to the edge line of the existing building's outer contour line to point D on the side of the existing building adjacent to the seismic source range with point D. Set the intersection of this line with the seismic isolation trench as point d, and set the endpoint of the seismic isolation trench adjacent to point d0.
[0016] (2) First, move the vibration source to point A on the edge of the area adjacent to the existing building within the vibration source range. When the vibration source is at point A, measure the horizontal acceleration a at each monitoring point. x测 And the measured vertical acceleration a y测 Compare with the standard horizontal acceleration a in step S2 respectively x控 Standard vertical acceleration a y控 For comparison, each monitoring point satisfies a. x测 ≤a x控 And a y测 ≤a y控 When h0 is reached, it is the effective depth of the isolation trench in section a0a. If any monitoring point does not meet the above requirements, the isolation trench in section a0a is deepened by 0.5m per increment, and after each deepening, the above requirements are checked again until every monitoring point meets the requirements. x测 ≤a x控 And a y测 ≤a y控 At this point, the excavation depth of the isolation trench in section a0a is the effective depth h of the isolation trench in section a0a. aoa ;
[0017] (3) Move the vibration source between points B and C on the edge of the area adjacent to the existing building within the vibration source range. Compare and determine whether the isolation trench in section bc meets the effective depth in the manner described in step (2). If it does not meet the requirements, continue excavating the isolation trench in section bc at a rate of 0.5m / excavation until each monitoring point meets the requirements of a. x测 ≤a x控 And a y测 ≤a y控 At that time, the excavation depth of the isolation trench in section bc is the effective depth h of section bc of the isolation trench.bc ;
[0018] (4) Move the vibration source to point D on the edge of the area adjacent to the existing building within the vibration source range. Compare and determine whether the isolation trench of section d0d meets the effective depth in the manner described in step (2). If it does not meet the requirements, continue excavating the isolation trench of section d0d at a rate of 0.5m / time until each monitoring point meets the requirements. x测 ≤a x控 And a y测 ≤a y控 At that time, the excavation depth of the isolation trench in section d0d is the effective depth h of section d0d of the isolation trench. dod ;
[0019] (5) After determining the effective depth of the isolation trenches in segments a0a, bc and d0d, the isolation trench in segment ab between segments a0a and bc is linearly sloped from segment a0a to segment bc, and the isolation trench in segment cd between segments bc and d0d is linearly sloped from segment d0d to segment bc.
[0020] The preferred technical solution of the present invention is as follows: In step S1, the seismic isolation trench is located on the midline between the boundary line of the area near the existing building and the distance between the existing building and the seismic source, or on the side away from the seismic source.
[0021] The preferred technical solution of the present invention is as follows: In step S2, the seismic fortification intensity and corresponding horizontal acceleration a of the vibration source and the area where the building is located are determined according to the "Code for Seismic Design of Buildings" GB50011. x控 and vertical acceleration a y控 If a building or structure has special requirements that are stricter than the control standards, the higher standards should be applied, and the requirements should be set according to the actual situation.
[0022] A preferred technical solution of the present invention is as follows: In step S4, a monitoring point is set at each outward convex corner of the existing building outline, and an acceleration sensor in both vertical and horizontal directions is arranged at each monitoring point to monitor the vertical acceleration and horizontal acceleration of the outward convex corner in real time; the acceleration sensor includes a piezoelectric acceleration sensor, a piezoresistive acceleration sensor, a capacitive acceleration sensor, or a servo acceleration sensor.
[0023] The preferred technical solution of the present invention: the linear slope i1 of the isolation trench in section ab in step (5):
[0024] i1=(h bc -h aoa ) / L ab ,
[0025] Among them, h bc This represents the effective depth of the seismic isolation trench in section bc.
[0026] h aoa For a o The effective depth of the isolation trench in section a;
[0027] L ab This is the horizontal length of the isolation trench in section ab;
[0028] In step (5), the linear slope i2 of the cd isolation trench is:
[0029] i2=(h bc -h dod ) / L cd ;
[0030] Among them, h bc This represents the effective depth of the seismic trench in segment bc.
[0031] h dod For d o The effective depth of the isolation trench in section d;
[0032] L cd This is the horizontal length of the isolation trench in section cd.
[0033] The preferred technical solution of the present invention is as follows: In step (5), after linearly finding the slope of the isolation trench in segments bc and cd, the effective depth of segments bc and cd is further determined, and the determination process is as follows:
[0034] The vibration source was moved along segments AB and CD of the boundary line of the area adjacent to the existing building within the vibration source range, and the measured horizontal acceleration a at each monitoring point was recorded. x测 And the measured vertical acceleration a y测 Compared with the standard horizontal acceleration a in step S2 x控 Standard vertical acceleration a y控 By comparison, it is determined whether all monitoring points satisfy condition a when the vibration source is at each point within segments AB and CD. x测 ≤a x控 And a y测 ≤a y控 If the requirements are met, the corresponding depth of the isolation trench is the effective depth. If, at any point, the measured value is greater than the control value, and the requirements are not met, then a line is drawn connecting that point to the point that does not meet the requirements. The intersection of this line with the isolation trench is the location point of the isolation trench that does not meet the requirements. For the location point of the isolation trench that does not meet the requirements, the trench depth is increased by 0.5m per increment, extending 1m longitudinally to both sides, until the measured value meets the requirements. x测 ≤a x控 And a y测 ≤a y控 Requirements.
[0035] This invention provides a method for setting the effective depth of a seismic isolation trench. Based on practical engineering considerations, it takes into account the law of vibration propagation attenuation with distance and provides a quantitative method for determining the depth of the seismic isolation trench. This method can reduce earthwork excavation for the seismic isolation trench, lower construction costs, and effectively block the propagation of vibration. It is of great significance for reducing the impact of vibration on the environment and protecting surrounding buildings and structures. Attached Figure Description
[0036] Figure 1 This is a plan view of the seismic isolation trench in this invention;
[0037] Figure 2 yes Figure 1 Schematic diagram of the depth of the seismic isolation trench in section I-I;
[0038] Figure 3 yes Figure 1 Section layout diagram of section II-II. Detailed Implementation
[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments. Figures 1 to 3 All accompanying drawings are simplified versions of embodiments and are intended only to clearly and concisely illustrate the embodiments of the present invention. The technical solutions shown in the drawings below are specific solutions of embodiments of the present invention and are not intended to limit the scope of the claimed invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0040] The present invention provides a method for setting the effective depth of a seismic isolation trench, characterized by comprising the following steps:
[0041] S1. A seismic isolation trench is set between the seismic source area and the existing buildings and structures, with a width of 0.5 to 2m; the seismic isolation trench is located on the midline between the boundary line of the area near the existing buildings and the distance between the existing buildings and structures, or on the side away from the seismic source.
[0042] S2. Determine the seismic fortification intensity and corresponding standard horizontal acceleration a of the area where the vibration source and existing buildings and structures are located. x控 and standard vertical acceleration a y控 This refers to the safety control standards for buildings and structures; specifically, the seismic fortification intensity of the site and the corresponding standard horizontal acceleration a are determined according to the "Code for Seismic Design of Buildings" GB50011. x控 and standard vertical acceleration a y控 If a building or structure has special requirements that are stricter than the control standards, the higher standards should be applied.
[0043] S3. Connect the two endpoints A and D of the boundary line of the area adjacent to the existing building to each corner of the outer contour of the existing building. The area between the two outermost lines is the vibration influence range. The length of the seismic isolation trench exceeds the vibration influence range by at least 3m. The vibration source range refers to the entire range of movement of the vibration source that affects the existing building, such as the range affected by the movement of a motor vehicle or dynamic compaction.
[0044] S4. Set up monitoring points at each outward convex corner of the existing building's outer contour line, and arrange vertical and horizontal acceleration sensors at each monitoring point to monitor the vertical and horizontal acceleration at each outward convex corner of the existing building's outer contour line in real time; the acceleration sensors include piezoelectric acceleration sensors, piezoresistive acceleration sensors, capacitive acceleration sensors, or servo acceleration sensors.
[0045] S5. The initial depth of the seismic isolation trench is set to h0, the foundation depth of the existing building structure, and the seismic isolation trench is excavated according to the initially set depth h0.
[0046] S6. After the initial excavation of the seismic isolation trench is completed, the vibration source is controlled to move along the edge of the area adjacent to the existing building within the vibration source range. During the movement, the measured horizontal acceleration 'a' at each corner of the outer contour of the existing building is monitored through the monitoring points set up in step S4 when the vibration source moves to each position. x测 And the measured vertical acceleration a y测 And by comparing the measured horizontal acceleration a x测 And the measured vertical acceleration a y测 Compared with the standard horizontal acceleration a in step S2 x控 and standard vertical acceleration a y控 The size of the trough determines whether its depth meets the requirements.
[0047] When a at each monitoring point x测 ≤a x控 And a y测 ≤a y控 Then, the excavation depth of the isolation trench corresponding to the horizontal direction of the vibration source location is the effective depth.
[0048] If during the movement, the measured horizontal acceleration 'a' at each monitoring point... x测 And the measured vertical acceleration a y测 If the above requirements are not met, the depth of the isolation trench corresponding to the horizontal direction of the vibration source location is insufficient for the effective depth. The depth of the isolation trench in this area needs to be increased until the required depth for each monitoring point (a) is met. x测 ≤a x控 And a y测 ≤a y控At this point, the depth of the seismic isolation trench is the effective depth.
[0049] The process of determining the effective depth of the seismic isolation trench in this invention will be described in detail below with reference to the layout of the seismic isolation trench and monitoring points shown in the attached drawings. Figure 1 As shown in the embodiment, the existing building has a square outer contour and four monitoring points: measuring point 1, measuring point 2, measuring point 3, and measuring point 4. Measuring points 1 and 2 are closer to the vibration source area. Vertical and horizontal acceleration sensors are installed at each monitoring point. The seismic isolation trench is located between the existing building and the vibration source area. The two endpoints of the boundary line of the area adjacent to the existing building in the vibration source area are points A and D, respectively. The specific judgment process is as follows:
[0050] (1) As Figure 1 As shown, a line is drawn connecting the corner point (i.e., measuring point 1) closest to the edge line of the existing building's outer contour line to the side of the seismic source adjacent to the existing building, and point A. The intersection of this line with the seismic isolation trench is set as point a, and the endpoint of the seismic isolation trench adjacent to point a is set as point a0. Two horizontal lines are drawn connecting the two corner points closest to the edge line of the existing building's outer contour line to the side of the seismic source adjacent to the existing building, respectively. The positions of these horizontal lines to the edge line are set as points B and C, respectively. The intersections of these two horizontal lines with the seismic isolation trench are set as points b and c, respectively. A line is drawn connecting the corner point closest to the edge line of the existing building's outer contour line to the side of the seismic source adjacent to the existing building, and point D. The intersection of this line with the seismic isolation trench is set as point d, and the endpoint of the seismic isolation trench adjacent to point d is set as point d0.
[0051] (2) First, move the vibration source to point A on the edge of the area adjacent to the existing building within the vibration source range. When the vibration source is at point A, measure the horizontal acceleration a at each monitoring point. x测 And the measured vertical acceleration a y测 Compare with the standard horizontal acceleration a in step S2 respectively x控 Standard vertical acceleration a y控 For comparison, each monitoring point satisfies a. x测 ≤a x控 And a y测 ≤a y控 When h0 is reached, it is the effective depth of the isolation trench in section a0a. If any monitoring point does not meet the above requirements, the isolation trench in section a0a is deepened by 0.5m per increment, and after each deepening, the above requirements are checked again until every monitoring point meets the requirements. x测 ≤a x控 And a y测 ≤a y控 At this point, the excavation depth of the isolation trench in section a0a is the effective depth h of the isolation trench in section a0a. aoa ;
[0052] (3) Move the vibration source between points B and C on the edge of the area adjacent to the existing building within the vibration source range. Compare and determine whether the isolation trench in section bc meets the effective depth in the manner described in step (2). If it does not meet the requirements, continue excavating the isolation trench in section bc at a rate of 0.5m / excavation until each monitoring point meets the requirements of a. x测 ≤a x控 And a y测 ≤a y控 At that time, the excavation depth of the isolation trench in section bc is the effective depth h of section bc of the isolation trench. bc ;
[0053] (4) Move the vibration source to point D on the edge of the area adjacent to the existing building within the vibration source range. Compare and determine whether the isolation trench of section d0d meets the effective depth in the manner described in step (2). If it does not meet the requirements, continue excavating the isolation trench of section d0d at a rate of 0.5m / time until each monitoring point meets the requirements. x测 ≤a x控 And a y测 ≤a y控 At that time, the excavation depth of the isolation trench in section d0d is the effective depth h of section d0d of the isolation trench. dod ;
[0054] (5) After determining the effective depth of the isolation trenches in segments a0a, bc, and d0d, as follows: Figure 2 As shown, the isolation trench in segment ab between segments a0a and bc is linearly sloped from segment a0a to segment bc, and the isolation trench in segment cd between segments bc and d0d is linearly sloped from segment d0d to segment bc; the linear slope i1 of the isolation trench in segment ab is:
[0055] i1=(h bc -h aoa ) / L ab ,
[0056] Among them, h bc This represents the effective depth of the seismic isolation trench in section bc.
[0057] h aoa For a o The effective depth of the isolation trench in section a;
[0058] L ab This is the horizontal length of the isolation trench in section ab;
[0059] The linear slope i2 of the CD isolation trench:
[0060] i2=(h bc -h dod ) / L cd ;
[0061] Among them, h bc This represents the effective depth of the seismic trench in segment bc.
[0062] h dod For d o The effective depth of the isolation trench in section d;
[0063] L cd This is the horizontal length of the isolation trench in section cd.
[0064] (6) After linearly sloping the isolation trenches in segments BC and CD, the effective depth of segments BC and CD is further determined. The determination process is as follows:
[0065] The vibration source was moved along segments AB and CD of the boundary line of the area adjacent to the existing building within the vibration source range, and the measured horizontal acceleration a at each monitoring point was recorded. x测 And the measured vertical acceleration a y测 Compared with the standard horizontal acceleration a in step S2 x控 Standard vertical acceleration a y控 By comparison, it is determined whether all monitoring points satisfy condition a when the vibration source is at each point within segments AB and CD. x测 ≤a x控 And a y测 ≤a y控 If the requirements are met, the corresponding depth of the isolation trench is the effective depth. If, at any point, the measured value is greater than the control value, and the requirements are not met, then a line is drawn connecting that point to the point that does not meet the requirements. The intersection of this line with the isolation trench is the location point of the isolation trench that does not meet the requirements. For the location point of the isolation trench that does not meet the requirements, the trench depth is increased by 0.5m per increment, extending 1m longitudinally to both sides, until the measured value meets the requirements. x测 ≤a x控 And a y测 ≤a y控 Requirements;
[0066] For example, if the seismic source is located at point E and the measured value at the measuring point is greater than the control value, then point E is connected to the measuring point that does not meet the requirements to determine the location point e of the seismic isolation trench. Point e is extended 1m along the longitudinal direction of the trench to both sides, and the trench depth is increased by 0.5m per increment until the measured value at the measuring point is less than the control value. If the seismic source is located in segment GF and the measured value at the measuring point is greater than the control value, then points F and G are connected to the measuring point that does not meet the requirements to determine the location points f and g of the seismic isolation trench. Points f and g are extended 1m along the longitudinal direction of the trench to both sides, and the trench depth is increased by 0.5m per increment. After deepening, the slope of segment fg is linearly adjusted according to the original slope of segment ab until the measured value at the measuring point is less than the control value.
[0067] The invention will be further described below with reference to a specific embodiment. The embodiment is a commercial plot in Shuangta District, Chaoyang City, covering an area of approximately 170,000 square meters, of which approximately 100,000 square meters are backfilled soil areas. The site design adopts dynamic compaction foundation treatment with a compaction energy of 4000 kN·m. There are residential buildings on the south side of the site, and the closest distance to the dynamic compaction construction area (the area closest to the residential buildings is approximately 350m long) is approximately 80m. The residential buildings are single-story (the building dimensions are 11m*14m, and the length of the area closest to the construction area is 11m), using natural strip foundations with a depth of approximately 1.5m.
[0068] According to the "Code for Seismic Design of Buildings" GB50011, the seismic intensity in Shuangta District, Chaoyang City is 7°, the acceleration is 0.1g, and the earthquake belongs to the first group. Therefore, the horizontal acceleration a... x控 =0.1g and vertical acceleration a y控 =0.2g. Test compaction was conducted on the side near residential buildings. Seismic acceleration monitoring points were set up at 10m intervals on the side near the buildings. Based on the monitoring data a x测 =0.19g>0.1g and a y测 =0.22g>0.2g, the entire area of the house is within the vibration influence range, and horizontal and vertical acceleration monitoring points are set at each corner of the house.
[0069] The specific details of the seismic isolation trench installation are as follows:
[0070] ① Set up a seismic isolation trench between the dynamic compaction area and the residential buildings, with a trench width of 1m;
[0071] ②The influence range line is determined by connecting the corner of the dynamic compaction construction area with the corner of the residential building. The length of the seismic isolation trench is determined to be 209m by the intersection of the centerline of the seismic isolation trench and the seismic influence range line. The length of the seismic isolation trench is set to exceed the influence range by 3m on both sides. Therefore, the final length of the seismic isolation trench on site is 215m.
[0072] ③ The initial depth of the seismic isolation trench is set to 1.5m, the same as the foundation depth. At this point, when the dynamic compaction moves along the boundary line near the building, the data from the detection points at each corner of the house is used as a reference. x测 ≤a x控 =0.1g and a y测 ≤a y控 =0.2g, which meets the requirements, and no disputes or accidents occurred with the villagers during the trial compaction. Therefore, the depth and length of the seismic isolation trench currently set up meet the on-site construction requirements.
[0073] Based on actual measurements, this invention fully considers the effective depth and length of the seismic isolation trench, which can effectively block the propagation of vibration.
[0074] The above description is merely one embodiment of the present invention, and while it is detailed and specific, it should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. The scope of protection of the present invention should be determined by the appended claims.
Claims
1. A method for determining the effective depth of a seismic isolation trench, characterized in that... Includes the following steps: S1. A seismic isolation trench shall be installed between the seismic source area and the existing buildings and structures, with a width of 0.5 to 2m; S2. Determine the seismic fortification intensity and corresponding standard horizontal acceleration a of the area where the vibration source and existing buildings and structures are located. x控 and standard vertical acceleration a y控 This refers to the safety control standards for buildings and structures. S3. Connect the two endpoints A and D of the boundary line of the area adjacent to the existing building to each corner of the outer contour of the existing building. The area between the two outermost lines is the vibration influence range. The length of the seismic isolation trench exceeds the vibration influence range by at least 3m. S4. Set up monitoring points at each corner of the outer contour of the existing building to monitor the vertical and horizontal acceleration at each corner of the outer contour of the existing building in real time. S5. The initial depth of the seismic isolation trench is set to h0, the foundation depth of the existing building structure, and the seismic isolation trench is excavated according to the initially set depth h0; S6. After the initial excavation of the seismic isolation trench is completed, the vibration source is controlled to move along the edge of the area adjacent to the existing building within the vibration source range. During the movement, the measured horizontal acceleration 'a' at each corner of the outer contour of the existing building is monitored through the monitoring points set up in step S4 when the vibration source moves to each position. x测 And the measured vertical acceleration a y测 And by comparing the measured horizontal acceleration a x测 And the measured vertical acceleration a y测 Compared with the standard horizontal acceleration a in step S2 x控 and standard vertical acceleration a y控 The size of the trough determines whether its depth meets the requirements. When a at each monitoring point x测 ≤a x控 And a y测 ≤a y控 Then, the excavation depth of the isolation trench corresponding to the horizontal direction of the vibration source location is the effective depth. If during the movement, the measured horizontal acceleration 'a' at each monitoring point... x测 And the measured vertical acceleration a y测 If the above requirements are not met, the depth of the isolation trench corresponding to the horizontal direction of the vibration source location is insufficient for the effective depth. The depth of the isolation trench in this area needs to be increased until the required depth for each monitoring point (a) is met. x测 ≤a x控 And a y测 ≤a y控 At this point, the depth of the seismic isolation trench is the effective depth.
2. The method for setting the effective depth of a seismic isolation trench according to claim 1, characterized in that: In step S6, the vibration source is controlled to move along the edge of the area adjacent to the existing building within the vibration source range, and the measured horizontal acceleration α at each corner of the outer contour line of the existing building is monitored during the movement. x测 And the measured vertical acceleration a y测 The specific process for determining whether the depth of the seismic isolation trench meets the requirements is as follows: (1) Connect the corner point closest to the edge line of the existing building's outer contour line to point A on the side of the existing building adjacent to the seismic source range with point A. The intersection of this line with the seismic isolation trench is set as point a, and the endpoint of the seismic isolation trench adjacent to point a is set as point a0. Connect the two corner points closest to the edge line of the existing building's outer contour line to the side of the existing building adjacent to the seismic source range with the edge line of the existing building adjacent to the seismic source range horizontally. The positions of the horizontal lines to the edge line are set as points B and C, respectively. The intersections of the two horizontal lines with the seismic isolation trench are set as points b and c, respectively. Connect the corner point closest to the edge line of the existing building's outer contour line to point D on the side of the existing building adjacent to the seismic source range with point D. The intersection of this line with the seismic isolation trench is set as point d, and the endpoint of the seismic isolation trench adjacent to point d is set as point d0. (2) First, move the vibration source to point A on the edge of the area adjacent to the existing building. When the vibration source is at point A, measure the horizontal acceleration a at each monitoring point. x测 And the measured vertical acceleration a y测 Compare with the standard horizontal acceleration a in step S2 respectively x控 Standard vertical acceleration a y控 For comparison, each monitoring point satisfies a. x测 ≤a x控 And a y测 ≤a y控 When h0 is reached, it is the effective depth of the isolation trench in section a0a. If any monitoring point does not meet the above requirements, the isolation trench in section a0a is deepened by 0.5m per increment, and after each deepening, the above requirements are checked again until every monitoring point meets the requirements. x测 ≤a x控 And a y测 ≤a y控 At this point, the excavation depth of the isolation trench in section a0a is the effective depth h of the isolation trench in section a0a. aoa ; (3) Move the vibration source between points B and C on the edge of the area adjacent to the existing building within the vibration source range, and compare and determine whether the isolation trench in section bc meets the effective depth in the manner described in step (2). If it does not meet the requirements, continue excavating the isolation trench in section bc at a rate of 0.5m / time, so that each monitoring point meets the requirements of a. x测 ≤a x控 And a y测 ≤a y控 At that time, the excavation depth of the isolation trench in section bc is the effective depth h of section bc of the isolation trench. bc ; (4) Move the vibration source to point D on the edge of the area adjacent to the existing building within the vibration source range, and compare and determine whether the isolation trench of section d0d meets the effective depth in the manner described in step (2). If it does not meet the requirements, continue excavating the isolation trench of section d0d at a rate of 0.5m / time, so that each monitoring point meets the requirements of a. x测 ≤a x控 And a y测 ≤a y控 At that time, the excavation depth of the isolation trench in section d0d is the effective depth h of section d0d of the isolation trench. dod ; (5) After determining the effective depth of the isolation trenches in segments a0a, bc, and d0d, the isolation trench in segment ab between segments a0a and bc is linearly sloped from segment a0a to segment bc, and the isolation trench between segments bc and d0d is sloped. The isolation trench in section cd is sloped linearly from section d0d to section bc.
3. The method for setting the effective depth of a seismic isolation trench according to claim 1, characterized in that: In step S1, the seismic isolation trench is located on the midline between the boundary line of the area near the existing building and the distance between the existing building and the seismic source, or on the side away from the seismic source.
4. The method for setting the effective depth of a seismic isolation trench according to claim 1, characterized in that: In step S2, the seismic fortification intensity and corresponding horizontal acceleration a of the vibration source and the area where the building is located are determined according to the "Code for Seismic Design of Buildings" GB50011. x控 and vertical acceleration a y控 .
5. The method for setting the effective depth of a seismic isolation trench according to claim 1, characterized in that: In step S4, a monitoring point is set at each outward convex corner of the existing building outline, and acceleration sensors in both vertical and horizontal directions are arranged at each monitoring point to monitor the vertical and horizontal acceleration of the outward convex corner in real time.
6. The method for setting the effective depth of a seismic isolation trench according to claim 2, characterized in that: In step (5), the linear slope i1 of the isolation trench in section ab is: i1=(h bc -h aoa ) / L ab , Among them, h bc This represents the effective depth of the isolation trench in section bc. h aoa For a o The effective depth of the isolation trench in section a; L ab This is the horizontal length of the isolation trench in section ab; The linear slope i2 of the cd isolation trench in step (5) is: i2=(h bc -h dod ) / L cd ; Among them, h bc This represents the effective depth of the seismic trench in segment bc. h dod For d o The effective depth of the isolation trench in section d; L cd This is the horizontal length of the isolation trench in section cd.
7. The method for setting the effective depth of a seismic isolation trench as described in claim 2, characterized in that: In step (5), after linearly finding the slope of the isolation trenches in segments bc and cd, the effective depth of segments bc and cd is further determined. The determination process is as follows: The vibration source was moved along segments AB and CD of the boundary line of the area adjacent to the existing building within the vibration source range, and the measured horizontal acceleration a at each monitoring point was recorded. x测 And the measured vertical acceleration a y测 Compared with the standard horizontal acceleration a in step S2 x控 Standard vertical acceleration a y控 By comparison, it is determined whether all monitoring points satisfy condition a when the vibration source is at each point within segments AB and CD. x测 ≤a x控 And a y测 ≤a y控 If the requirements are met, the corresponding depth of the isolation trench is the effective depth. If, at any point, the measured value is greater than the control value, and the requirements are not met, then a line is drawn connecting that point to the point that does not meet the requirements. The intersection of this line with the isolation trench is the location point of the isolation trench that does not meet the requirements. For the location point of the isolation trench that does not meet the requirements, the trench depth is increased by 0.5m per increment, extending 1m longitudinally to both sides, until the measured value meets the requirements. x测 ≤a x控 And a y测 ≤a y控 Requirements.
Citation Information
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