CN113152476A - Excavation construction method for soft geological foundation pit of existing line station - Google Patents
Excavation construction method for soft geological foundation pit of existing line station Download PDFInfo
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- CN113152476A CN113152476A CN202110506693.1A CN202110506693A CN113152476A CN 113152476 A CN113152476 A CN 113152476A CN 202110506693 A CN202110506693 A CN 202110506693A CN 113152476 A CN113152476 A CN 113152476A
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/02—Foundation pits
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/02—Foundation pits
- E02D17/04—Bordering surfacing or stiffening the sides of foundation pits
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D19/00—Keeping dry foundation sites or other areas in the ground
- E02D19/06—Restraining of underground water
- E02D19/12—Restraining of underground water by damming or interrupting the passage of underground water
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/045—Underground structures, e.g. tunnels or galleries, built in the open air or by methods involving disturbance of the ground surface all along the location line; Methods of making them
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Abstract
The invention is suitable for the technical field of foundation pit excavation construction, and provides a soft geological foundation pit excavation construction method of an existing line station, which comprises the following steps: s1, construction preparation; s2, monitoring the foundation pit to be excavated; s3, excavating the main body of the station; s4, arranging a steel support servo system on the main body of the station, and performing construction monitoring, automatic monitoring of data analysis deformation rules and automatic control on main body excavation of the station through the steel support servo system; and S5, performing seepage water stop treatment on the excavated foundation pit. The invention can improve the construction efficiency of the foundation pit, has good automatic monitoring effect, high construction safety and wide application.
Description
Technical Field
The invention belongs to the technical field of foundation pit excavation construction, and particularly relates to a soft geological foundation pit excavation construction method of an existing line station.
Background
With the development of cities, rail transit is used as an important transportation hub of cities, and more cities begin to be built. The track traffic of large cities such as Shanghai and Suzhou is developed more rapidly, and many subway lines are planned at positions close to existing lines for convenient transfer, so that great difficulty is brought to the structural safety of existing line stations and the construction of soft geological foundation pits of newly-built lines. The platform of two numbers lines of current track traffic is mostly the ground transfer, and the clear interval only has 5.5m between the two, and the construction degree of difficulty is great, and the efficiency of construction is low, and the security of construction is poor.
Disclosure of Invention
The invention provides a soft geological foundation pit excavation construction method for an existing line station, and aims to solve the technical problems.
The invention is realized in such a way that a soft geological foundation pit excavation construction method of an existing line station comprises the following steps:
s1, construction preparation;
s2, monitoring the foundation pit to be excavated;
s3, excavating the main body of the station;
s4, arranging a steel support servo system on the main body of the station, and performing construction monitoring, automatic monitoring of data analysis deformation rules and automatic control on main body excavation of the station through the steel support servo system;
and S5, performing seepage water stop treatment on the excavated foundation pit.
Further, the step S3 specifically includes:
s31, constructing the ground wall of the main body;
s32, constructing the crown beam;
s33, checking and accepting the foundation pit excavation;
s34, excavating the foundation pit in a vertical layering and longitudinal segmentation manner;
s35, excavating a first section of the foundation pit to form a bottom;
and S36, performing flow process according to the structure of the main body.
Further, the step S1 specifically includes:
s21, arranging monitoring points;
s22, monitoring the station hall layer of the operating line;
s23, monitoring frequency;
s24, monitoring, early warning and alarming;
and S25, automatically monitoring the station layer.
Further, the step S21 specifically includes:
selecting a building in an influence range to carry out monitoring point arrangement, then arranging underground pipeline monitoring points, then arranging municipal road monitoring points, arranging surface monitoring points by combining the conditions of the building, the bridge, the underground pipeline and the road monitoring points, and then arranging the horizontal displacement of the pile top of the enclosure structure, the deformation measuring points of the pile body and the supporting axial force by combining the surrounding environment condition and the enclosure structure condition;
arranging measuring points of the surrounding environment and the building envelope system in the same section;
arranging the measuring points at the positions capable of reflecting construction so as to ensure the engineering safety state;
and arranging temporary monitoring points on the ground at the division lines of the driving lanes.
Further, the step S25 specifically includes:
monitoring range;
monitoring a project;
automatic monitoring points of the platform are distributed;
carrying out real-time observation through a measuring robot;
and feeding back early warning information according to the measuring robot.
Further, the step S4 specifically includes:
according to the shape of the foundation pit and the excavation requirement, arranging a field control station and a pump station of the automatic axial force compensation system in a straight line along the edge of the foundation pit, adhering the arrangement positions of the field control station and the pump station to the principle of shortest line, and completing program debugging of equipment installation, a single system and a total system;
assembling the end of the steel support sleeve box and the steel support in advance, erecting the steel support according to the excavation progress of the foundation pit, installing a jack, setting a system pressure control value on a monitoring station according to the designed axial force, and finishing the step-by-step application of the designed pre-applied axial force; various initial values of monitoring data are collected for synchronous monitoring.
Further, the step S5 specifically includes:
s51, cutting and seam checking;
s52, carrying out high-pressure jet grouting on the pile;
and S53, stopping water at the leakage point.
Further, the step S53 specifically includes:
s531, performing double-liquid-slurry water stop treatment; according to the depth of the leakage position, grouting holes are punched in the earth surface on the outer side of the enclosure structure, high-pressure grouting construction is carried out, and when grouting slurry cannot be pressed into the leakage point, the grouting holes return slurry;
s532, polyurethane water stop treatment; aiming at the leakage point of the ground wall, the oil-based polyurethane is adopted for leaking stoppage and water stopping, the slurry immediately undergoes chemical reaction after meeting water, the viscosity of the slurry is gradually increased, finally water-insoluble gel is generated, carbon dioxide gas is generated at the same time, the slurry is diffused towards the periphery under the action of expansion force generated by the gas, the slurry is pressed into the pore, and the pore is filled compactly to realize sealing.
Further, the step S531 specifically includes:
cleaning; finely checking and analyzing the leakage condition, determining the position and the distance of a grouting hole, cleaning a region needing construction, chiseling precipitates on the surface of concrete, and ensuring the surface to be clean;
drilling; drilling pressure relief holes along the periphery of the hole by using a drilling tool, wherein the diameter of a drill bit is 14mm, the drilling angle is preferably less than or equal to 45 degrees, the drilling depth is less than or equal to 2/3 of the structural needle head, and the drill hole needs to penetrate through a main water leakage hole in an inclined mode;
burying a mouth; observing the pressure of the main water leakage hole, burying the grouting water stopping needle head by using the quick-drying plugging agent when the pressure of water flow is not high, and installing the expansion water stopping needle head on other water leakage holes respectively when the structure reaches certain strength and does not leak, screwing the expansion water stopping needle head by using a special inner hexagonal wrench, so that no gap exists between the periphery of the grouting nozzle and a drilled hole, no water leakage exists, and the expansion water stopping needle heads are also sequentially installed on the wall surface in case of slow seepage.
Grouting; using a high-pressure grouting machine to perform pressure test, and grouting polyurethane grouting liquid into the grouting holes under the condition that the pressure of the concrete structure is not exceeded;
disassembling a nozzle; and after the grouting is finished for 24 hours, removing or knocking off the exposed grouting nozzle after the grouting is confirmed to be leak-proof, and cleaning the solidified leaked grouting liquid.
The beneficial effect achieved by the invention is that the embodiment of the invention is implemented through S1 and construction preparation; s2, monitoring the foundation pit to be excavated; s3, excavating the main body of the station; s4, arranging a steel support servo system on the main body of the station, and performing construction monitoring, automatic monitoring of data analysis deformation rules and automatic control on main body excavation of the station through the steel support servo system; and S5, performing seepage water stop treatment on the excavated foundation pit. The invention can improve the construction efficiency of the foundation pit, has good automatic monitoring effect, high construction safety and wide application.
Drawings
FIG. 1 is a flow chart of a soft geological foundation pit excavation construction method of an existing line station provided by the invention;
FIG. 2 is a flow chart of monitoring of the soft geological foundation pit excavation construction method of the existing line station provided by the invention;
FIG. 3 is a flow chart of main excavation of the soft geological foundation pit excavation construction method of the existing line station provided by the invention;
FIG. 4 is a flow chart of foundation pit leakage water stopping of the soft geological foundation pit excavation construction method of the existing line station provided by the invention;
fig. 5 is a flow chart of the water stopping at the leakage point provided by fig. 4 of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In the embodiment of the invention, the foundation pit to be excavated is monitored through S1; s2, excavating the main body of the station; s3, arranging a steel support servo system on the main body of the station, and performing construction monitoring, automatic monitoring of data analysis deformation rules and automatic control on main body excavation of the station through the steel support servo system; and S4, performing seepage water stop treatment on the excavated foundation pit. The invention can improve the construction efficiency of the foundation pit, has good automatic monitoring effect, high construction safety and wide application.
Example one
Referring to the attached drawing 1, fig. 1 is a flow chart of a soft geological foundation pit excavation construction method of an existing line station provided by the invention. The invention provides a soft geological foundation pit excavation construction method of an existing line station, which comprises the following steps: and S1, construction preparation.
Specifically, before the construction, the work arrangement of excavation of the foundation pit, allocation by constructors, and the like need to be prepared. The construction drawing is confirmed by a technician, and the construction drawing is handed to a constructor after the construction drawing is confirmed to be correct, so that the constructor can operate the construction drawing, and the excavation efficiency of the foundation pit is improved.
And S2, monitoring the foundation pit to be excavated.
Specifically, monitoring points are arranged on the foundation pit and the operation station before the foundation pit is excavated, the existing line station is monitored, the influence of foundation pit excavation on the operation station is comprehensively analyzed by combining the horizontal displacement of the foundation pit ground wall, the surface sedimentation, the water level monitoring and other items, and the safety of the operation station is ensured.
And S3, excavating the main body of the station.
Specifically, during foundation pit excavation, in order to reduce deformation of the foundation pit and the ground and ensure construction safety, the foundation pit excavation strictly follows the requirements of construction organization design, the foundation pit construction is guided by using a space-time effect principle, the foundation pit excavation adopts longitudinal segmentation and vertical layered step type excavation, the excavation length of each section is controlled to be 20-30 m, the thickness of each layer is not more than 3m, and the excavation is strictly forbidden to be in a pot bottom shape. The height of the adjacent soil body in the pit is not more than 2m, the permanent retention gradient of sandy soil in the pit is not steeper than 1:3, the gradient of the rest soil layers is not steeper than 1:2.5, the stability of the longitudinal soil slope is ensured, and triangular soil protection slope is required to be reserved around the foundation pit. When a section (6-8 m) is excavated, the excavation is stopped when the foundation pit is excavated to a position 0.5m below the designed elevation of the support, the support is erected in time, and pre-applied axial force is applied. After the support frame is erected, the stability of the steel support is checked and confirmed, and excavation construction can be continued after safety.
After foundation pit excavation one end falls to the end, carry out major structure flow process immediately, the earthwork excavation goes on with major structure simultaneously, guarantees that the steel shotcrete quantity is minimum in the foundation pit, ensures the outer station safety of transporting of hole.
S4, setting a steel support servo system on the main body of the station, and carrying out construction monitoring, automatic monitoring data analysis and deformation rule analysis and automatic control on the main body excavation of the station through the steel support servo system.
Specifically, the construction of the automatic steel support axial force compensation system is closely independent of the steel support frame, the automatic axial force compensation system needs to be processed and assembled 3 months in advance, and equipment and a line power supply system are arranged 15d in advance on site. The deformation rule is analyzed through construction monitoring and automatic monitoring data, and the deformation rule is compared with a design theory calculation deformation value, so that the steel support pre-applied axial force can be adjusted, the construction guidance design purpose is achieved, the site construction is dynamically guided, and the deformation is better controlled. During on-site monitoring, for example, when deformation of a foundation pit or an adjacent operation line or an important building (structure) is suddenly increased, on-site operators on duty quickly increase the design control axial force of the steel support at a monitoring station (or an operation station), so that the increase of the support axial force is realized by pressurization, and the deformation is controlled effectively in real time.
And S5, performing seepage water stop treatment on the excavated foundation pit.
Concrete for carry out the undercutting at the foundation ditch excavation in-process and examine the seam, if the seepage condition appears, should adopt polyurethane or biliquid thick liquid in time to carry out leaking stoppage stagnant water construction, prevent that groundwater from losing and causing the influence to existing line station.
During specific implementation, monitoring a foundation pit to be excavated by performing preparation work before excavation; excavating a main body of a station; a steel support servo system is arranged on the main body of the station, and construction monitoring, automatic monitoring, data analysis and deformation rule analysis and automatic control are carried out on the main body excavation of the station through the steel support servo system; the leakage water stopping treatment is carried out on the excavated foundation pit. The invention can improve the construction efficiency of the foundation pit, has good automatic monitoring effect, high construction safety and wide application. By planning the excavation process of the foundation pit, the influence of the time space effect on the foundation pit is reduced, and the displacement deformation of the enclosure structure caused by the attenuation of the axial force of the steel support is thoroughly avoided by adopting the steel support servo axial force system, so that the displacement deformation of the foundation pit structure is effectively controlled, and the excavation safety of the foundation pit is ensured. Meanwhile, the settlement and deformation of adjacent operation lines are effectively controlled, and the safe operation of the operation lines is ensured.
Referring to fig. 3, fig. 3 is a flowchart of main excavation of the soft geological foundation pit excavation construction method for the existing line station according to the present invention. As an optional embodiment of the present invention, the step S2 specifically includes:
s31, constructing the ground wall of the main body;
s32, constructing the crown beam;
s33, checking and accepting the foundation pit excavation;
s34, erecting steel supports, monitoring, digging and detecting seams, and excavating the foundation pit in a vertical layering and longitudinal segmentation manner;
s35, excavating a first section of the foundation pit to form a bottom;
and S36, performing flow process according to the structure of the main body.
When the method is specifically implemented, the foundation pit excavation adopts longitudinal segmentation and vertical layered stepped excavation, the excavation length of each segment is controlled to be 20-30 m, the thickness of each layer is not more than 3m, and the excavation is strictly forbidden to be in a pot bottom shape. The height of the adjacent soil body in the pit is not more than 2m, the permanent retention gradient of sandy soil in the pit is not steeper than 1:3, the gradient of the rest soil layers is not steeper than 1:2.5, the stability of the longitudinal soil slope is ensured, and triangular soil protection slope is required to be reserved around the foundation pit. When a section (6-8 m) is excavated, the excavation is stopped when the foundation pit is excavated to a position 0.5m below the designed elevation of the support, the support is erected in time, and pre-applied axial force is applied. After the support frame is erected, the stability of the steel support is checked and confirmed, and excavation construction can be continued after safety.
In the process of excavation of the foundation pit, water leakage at the joint of the ground wall is easy to occur, and the cut and the joint inspection are needed. And after the cut and the seam are detected, the position of the seam of the ground wall is determined to have no leakage, so that the excavation construction of the layer of earth can be carried out.
The inclinometer pipe is pre-buried in the construction process of the ground wall, so that the condition that the inclinometer pipe fails after the construction of the ground wall is finished is prevented. Every steel shotcrete axle power servo system all installs, requires 24 hours to arrange the special messenger and tours to carry out data comparison work, prevents that the foundation ditch from warping and leading to the increase of axle power. Monitoring is carried out according to the frequency of the scheme, and overall data analysis is carried out, if the inclinometer pipe needs to be analyzed corresponding to the axial force of the steel support, a conclusion cannot be set by only looking at one group of data. The method is characterized in that a cut is cut and a seam is detected in the process of excavation of a foundation pit, and if leakage occurs, polyurethane or double-liquid slurry is adopted to perform leaking stoppage and water stopping construction in time, so that influence on an existing line station due to underground water loss is prevented. The main structure construction is timely carried out after the first section of foundation pit excavation falls to the bottom, the condition that the exposure time of the foundation pit is too long is prevented, and the deformation is increased after the space effect is increased during foundation pit excavation, so that the existing line station structure is influenced.
The foundation pit earthwork excavation is constructed in a vertically layered and longitudinally segmented step-type mode, and after one end falls to the bottom, the foundation pit earthwork excavation and the main structure operation are simultaneously constructed, so that the time-space effect generated by the exposure of the foundation pit is reduced. The excavation process is strictly implemented, the cut is inspected to detect the sewing degree, the leakage of the joint part of the ground wall is prevented, and the influence of underground water reduction on the existing station is reduced. The steel support is erected in time in the excavation process of the foundation pit, the height difference between the steel support and the top elevation of the soil surface is not more than 50cm, the steel support adopts an axial force servo system, loss axial force is automatically compensated, and deformation of the foundation pit is reduced. The foundation pit monitoring is carried out by adopting a conventional method, the building settlement of the existing line station, the axial force of the foundation pit and the inclination measurement monitoring of the enclosure structure are mainly carried out, and the data is required to be integrally analyzed in the monitoring process. And monitoring the platform layer track of the existing line station by using an automatic monitoring system, and transmitting data to guide site construction by using the monitoring data.
Referring to fig. 2, fig. 2 is a flow chart of monitoring of a soft geological foundation pit excavation construction method of an existing line station according to the present invention. In this embodiment of the present invention, the step S2 specifically includes:
s21, arranging monitoring points;
s22, monitoring the station hall layer of the operating line;
s23, monitoring frequency;
s24, monitoring, early warning and alarming;
and S25, automatically monitoring the station layer.
In specific implementation, measuring points are optimized and distributed by comprehensively considering the surrounding environment and the surrounding structure system condition, generally, building (structure) in an influence range is selected to be distributed with monitoring points, underground pipeline monitoring points are distributed, municipal road monitoring points are distributed, surface monitoring points are distributed according to the conditions of the building (structure), a bridge, the underground pipeline and the road monitoring points, and then the surrounding environment condition and the surrounding structure condition are combined to distribute the surrounding structure pile (wall) top horizontal displacement, the pile (wall) body deformation measuring points and the supporting shaft force. And aiming at the operated line, building settlement points are distributed on the ground station hall layer, and the deformation of the building is monitored every day during the construction of the foundation pit. The basic principle of monitoring frequency arrangement is that important change processes of items to be monitored of monitored objects can be reflected systematically on the premise of ensuring the safety of a foundation pit, and change moments are not omitted. And from the reality, combine the characteristic of this project for monitor work runs through throughout foundation ditch engineering and underground works construction overall process, and combine together with the progress of construction, satisfy the requirement of construction operating mode, arrange frequency and monitoring process under the principle of "comprehensive, accurate, timely", establish a complete monitoring early warning system as far as possible.
In this embodiment of the present invention, the step S21 specifically includes:
selecting a building in an influence range to carry out monitoring point arrangement, then arranging underground pipeline monitoring points, then arranging municipal road monitoring points, arranging surface monitoring points by combining the conditions of the building, the bridge, the underground pipeline and the road monitoring points, and then arranging the horizontal displacement of the pile top of the enclosure structure, the deformation measuring points of the pile body and the supporting axial force by combining the surrounding environment condition and the enclosure structure condition;
arranging measuring points of the surrounding environment and the building envelope system in the same section;
arranging the measuring points at the positions capable of reflecting construction so as to ensure the engineering safety state;
and arranging temporary monitoring points on the ground at the division lines of the driving lanes.
In specific implementation, the measuring points are optimized and distributed by comprehensively considering the surrounding environment and the building enclosure system condition, generally, building (structure) buildings in an influence range are selected to be distributed with monitoring points, underground pipeline monitoring points are distributed, municipal road monitoring points are distributed, surface monitoring points are distributed according to the conditions of the building (structure) buildings, bridges, underground pipelines and road monitoring points, and then the horizontal displacement of the top of the building enclosure pile (wall), the deformation measuring points of the pile (wall) body and the supporting shaft force are distributed according to the surrounding environment condition and the building enclosure condition. The measuring points of the surrounding environment and the building envelope system are arranged in the same section as much as possible. The measuring points are arranged at typical positions capable of reflecting construction influences, and the engineering safety state can be reflected practically. The arrangement of the temporary ground monitoring points must be reasonably optimized, the universality of monitoring distribution points (namely main bodies and auxiliary monitoring distribution points, and monitoring distribution points of third parties and construction parties) is improved, and the number of the monitoring points is reasonably reduced on the premise of not reducing the monitoring effect. The following principles should be adhered to in the spotting process: firstly, avoiding pedestrian crosswalk and other dense pedestrian stream places as much as possible; and secondly, avoiding the traffic lane and arranging the traffic lane at the position near the dividing line of the traffic lane as much as possible. Monitoring points are laid by a monitoring unit of a construction party according to a construction monitoring scheme after being evaluated by experts, the arrangement of the monitoring points is ensured to meet the requirements before monitoring, and a third-party monitoring unit and the construction monitoring unit synchronously acquire initial values during monitoring at the same point.
In this embodiment of the present invention, the step S25 specifically includes:
monitoring range;
monitoring a project;
automatic monitoring points of the platform are distributed;
carrying out real-time observation through a measuring robot;
and feeding back early warning information according to the measuring robot.
In specific implementation, the monitoring range is determined according to the principle that the length of the construction project projected on the rail transit line extends 50m forwards and backwards in the line direction. The corresponding position and the influence length of each station and each section. The corresponding monitoring method is adopted only for the object and the monitoring project which need to be monitored.
The monitoring object can be rail transit structure deformation monitoring. The monitoring items comprise a structure horizontal displacement monitoring section, a structure vertical displacement monitoring section, a structure clearance convergence section, a ballast bed structure vertical deformation monitoring point, track structure deformation monitoring, track structure water leakage and a structure crack. And monitoring by using a corresponding monitoring method according to the corresponding monitoring items, wherein the monitoring method sequentially comprises automatic monitoring, calculation by using the arch waist point, manual monitoring, inspection tour and the like.
A section is arranged every 8m of a station in a direct influence area, a section is arranged every 10 m in an indirect influence area, the number of side walls is 2, the number of ballast beds is 1, and each section is 3. When observation is carried out, the measurement robots of the come cards TS30 and TS50 are adopted to observe in an ATR mode, before each observation period starts, 4 datum points are observed at least 4 times, the coordinates of a measured station are calculated and compared with an initial value, and if the coordinates of the measured station exceed the limit, the coordinates of the measured station are measured again and corrected until the tolerance requirement is met. And (3) performing learning measurement on each monitoring point according to the section by using a learning measurement function in matched GeoMoS software, and automatically observing all the monitoring points by using a learning measurement result in the later monitoring process.
According to the construction plan, the monitoring frequency is properly reduced after the data are stable. And when abnormal conditions or field working conditions occur, the monitoring frequency is encrypted.
When the data analysis confirms that the early warning state is achieved, on one hand, monitoring frequency is increased, on-site tracking and inspection is achieved, on the other hand, monitoring units quickly report early warning information to relevant units such as rail companies, supervisors, owners and design by taking shortcuts such as oral reports, telephone reports, short message reports or network forms at the first time to confirm warning levels, warning contact lists and warning written data information are filled immediately, and written files are sent to relevant units in time. And (4) implementing the processing scheme after the related units discuss, adopting corresponding measures by the construction units according to the processing scheme, tracking and monitoring by the monitoring units, and canceling the early warning state after confirming that the engineering reaches the safe state according to the monitoring condition.
According to the monitoring control indexes given by a design unit and an evaluation unit, the early warning state of a monitoring point in the construction process is divided into three stages from small to large according to the severity: yellow monitoring and early warning, orange monitoring and early warning and red monitoring and early warning. And (4) taking corresponding measures according to the deformation and deformation rate conditions of the field monitoring project measuring points.
For example, the accumulated value of the yellow monitoring and early warning actual measurement reaches the accumulated control value U01When the content is 60% to less than 80%; or the daily rate of change reaches the rate of change control value U0260% to less than 80%. And sending early warning flash report, encrypting and monitoring, and assisting in analyzing reasons. Orange monitoring early warning actual measurement accumulated value reaches accumulated value control value U0180% of (A) and less than 100%; or the daily rate of change reaches the rate of change control value U0280% to less than 100%. Sending early warning flash report, carrying out encryption monitoring, starting a consultation mechanism, and taking measures of adjusting construction progress, optimizing construction parameters, perfecting technological methods and the like. The accumulated value of the red monitoring and early warning actual measurement reaches an accumulated value control value U01When the current is over; or the daily rate of change reaches the rate of change control value U02When the current is over; or when there is a sharp increase in the rate of daily change. Sending a preambleAlarming, monitoring by encryption, starting a consultation mechanism and an emergency plan, and immediately taking necessary measures such as reinforcement or stopping jacking.
In this embodiment of the present invention, the step S4 specifically includes:
according to the shape of the foundation pit and the excavation requirement, arranging a field control station and a pump station of the automatic axial force compensation system in a straight line along the edge of the foundation pit, adhering the arrangement positions of the field control station and the pump station to the principle of shortest line, and completing program debugging of equipment installation, a single system and a total system;
assembling the end of the steel support sleeve box and the steel support in advance, erecting the steel support according to the excavation progress of the foundation pit, installing a jack, setting a system pressure control value on a monitoring station according to the designed axial force, and finishing the step-by-step application of the designed pre-applied axial force; various initial values of monitoring data are collected for synchronous monitoring.
Referring to fig. 4, fig. 4 is a flow chart of foundation pit leakage water stopping in the soft geological foundation pit excavation construction method of the existing railway station. In this embodiment of the present invention, the step S5 specifically includes:
s51, cutting and seam checking;
s52, carrying out high-pressure jet grouting on the pile;
and S53, stopping water at the leakage point.
In the concrete implementation, in the process of excavation construction of the foundation pit, a slotting and seam checking system must be executed. Aiming at the joint part of each ground wall, the cut is carried out before one-layer earthwork excavation, and whether the ground wall has leakage points or not is checked. If not, performing excavation earthwork construction after backfilling; if the emergency water stopping device exists, emergency personnel are immediately organized to carry out water stopping treatment. The south side ground of station foundation ditch links wall seam crossing and establishes 2 high pressure jet grouting stake stagnant water, high pressure jet grouting stake degree of depth scope: 1m below the field level ground to 3m below the pit bottom. And water is stopped at the leakage point, so that the safety is higher in the construction process.
Referring to fig. 5, fig. 5 is a flow chart of the water stopping at the leakage point provided by fig. 4 of the present invention. In this embodiment of the present invention, the step S53 specifically includes:
s531, performing double-liquid-slurry water stop treatment; according to the depth of the leakage position, grouting holes are punched in the earth surface on the outer side of the enclosure structure, high-pressure grouting construction is carried out, and when grouting slurry cannot be pressed into the leakage point, the grouting holes return slurry;
s532, polyurethane water stop treatment; aiming at the leakage point of the ground wall, the oil-based polyurethane is adopted for leaking stoppage and water stopping, the slurry immediately undergoes chemical reaction after meeting water, the viscosity of the slurry is gradually increased, finally water-insoluble gel is generated, carbon dioxide gas is generated at the same time, the slurry is diffused towards the periphery under the action of expansion force generated by the gas, the slurry is pressed into the pore, and the pore is filled compactly to realize sealing.
When the method is specifically implemented, the double-slurry water stopping treatment is used for drilling grouting holes on the ground surface outside the enclosure structure according to the depth of a leakage position, and high-pressure grouting construction is carried out. The slurry adopts double-fluid slurry, the water cement ratio is 1:0.75, namely 3 bags of cement are added into a barrel of water, and the mass ratio of the cement slurry to the water glass is 1: 1. Grouting stop time: the grouting slurry can not be pressed into the leakage point until the grouting hole returns. The polyurethane water stopping treatment is used for stopping leakage and stopping water by adopting oil polyurethane aiming at a leakage point of a ground wall. The slurry immediately takes place chemical reaction after meeting water, the viscosity of the slurry gradually increases, finally water-insoluble gel is generated, and carbon dioxide gas is generated at the same time. The slurry is diffused to the periphery under the action of expansion force generated by gas, and the slurry is pressed into the hole (gap) to make the hole gap be tightly filled so as to attain the goal of stopping water and preventing seepage. The construction sequence is as follows: the construction method comprises the following steps of erecting a construction platform → connecting a power supply, a water source → analyzing cracks (inertial seams and non-inertial seams) → impact drilling (distributing points along curves according to concrete cracks) → pre-embedding of an injection needle → high-pressure grouting (expanded polyurethane) → shoveling of the injection needle → flexible cement leveling → cleaning of a crack surface → a next process.
In this embodiment of the present invention, the step S531 specifically includes:
cleaning; finely checking and analyzing the leakage condition, determining the position and the distance of a grouting hole, cleaning a region needing construction, chiseling precipitates on the surface of concrete, and ensuring the surface to be clean;
drilling; drilling pressure relief holes along the periphery of the hole by using a drilling tool, wherein the diameter of a drill bit is 14mm, the drilling angle is less than or equal to 45 degrees, the drilling depth is less than or equal to 2/3 of the structural needle head, and the drill hole needs to penetrate through the main water leakage hole in an inclined mode;
burying a mouth; observing the pressure of the main water leakage hole, burying the grouting water stopping needle head by using the quick-drying plugging agent when the pressure of water flow is not high, and installing the expansion water stopping needle head on other water leakage holes respectively when the structure reaches certain strength and does not leak, screwing the expansion water stopping needle head by using a special inner hexagonal wrench, so that no gap exists between the periphery of the grouting nozzle and a drilled hole, no water leakage exists, and the expansion water stopping needle heads are also sequentially installed on the wall surface in case of slow seepage.
Grouting; using a high-pressure grouting machine to perform pressure test, and grouting polyurethane grouting liquid into the grouting holes under the condition that the pressure of the concrete structure is not exceeded;
disassembling a nozzle; and after the grouting is finished for 24 hours, removing or knocking off the exposed grouting nozzle after the grouting is confirmed to be leak-proof, and cleaning the solidified leaked grouting liquid.
In specific implementation, 1) cleaning: and (5) checking and analyzing the leakage condition in detail, and determining the position and the distance of the grouting holes. Cleaning the area needing construction, chiseling off the precipitate on the concrete surface, and ensuring the surface to be clean.
2) Drilling: a drilling tool is used for drilling pressure relief holes along the periphery of the hole, the diameter of a drill bit is 14mm, the drilling angle is preferably less than or equal to 45 degrees, the drilling depth is less than or equal to 2/3 of the structure needle head, and the drill hole needs to penetrate through the main water leakage hole in an inclined mode. But the structure can not be punched through, and the dust in the holes with large running water can be automatically washed clean. The slow seepage of the wall surface is to drill plum blossom holes on the water seepage surface. And (5) washing the grouting hole by using a cleaning machine until the water outlet of the grouting hole is clear, and carrying out the next step of work.
3) Burying a nozzle: observing the pressure of the main water leakage hole, burying and injecting the grouting water-stopping needle head by using the quick-drying plugging agent when the pressure of water flow is not high, and (according to the construction condition, driving the wooden wedge and then plugging by using the quick-drying plugging agent, and drilling the wooden wedge again after the structure is stable and then installing the expansion water-stopping needle head). When the structure reaches a certain strength and does not leak, the other water drainage holes are respectively provided with expansion water stop needle heads and are screwed up by a special inner hexagonal wrench, so that no gap exists between the periphery of the grouting nozzle and the drilled hole, and the water does not leak. The wall surface is slowly infiltrated and is also sequentially provided with the expansion water stopping needle heads. The water leakage points are respectively provided with 25cm, 10cm and 8cm water stopping needle heads in a staggered mode according to levels, so that grouting can be completely and compactly performed from the deep layer to the surface layer. Blocking all holes and gaps.
4) Grouting: and (4) using a high-pressure grouting machine for pressure test, wherein the pressure test cannot exceed the pressure bearing range of the concrete structure. And pouring polyurethane grouting liquid into the grouting holes. The single holes are continuously processed one by one. And (3) after the adjacent holes start to discharge grout, keeping the pressure for 3-5 minutes, stopping grouting the holes, and grouting the adjacent grouting holes. And after all the holes are filled, returning to the first grouting hole, and grouting again to ensure the maximum pressure. The grouting sequence of the wall surface is from bottom to top; after all the holes are filled, the grouting holes are returned to the first previous grouting hole for refilling once.
5) Removing the nozzle: and after the grouting is finished for 24 hours, removing or knocking off the exposed grouting nozzle after no leakage is confirmed. And cleaning the solidified spilled grouting liquid.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (9)
1. A soft geological foundation pit excavation construction method of an existing line station is characterized by comprising the following steps:
s1, construction preparation;
s2, monitoring the foundation pit to be excavated;
s3, excavating the main body of the station;
s4, arranging a steel support servo system on the main body of the station, and performing construction monitoring, automatic monitoring of data analysis deformation rules and automatic control on main body excavation of the station through the steel support servo system;
and S5, performing seepage water stop treatment on the excavated foundation pit.
2. The soft geological foundation pit excavation construction method of the existing line station as set forth in claim 1, wherein the step S3 specifically includes:
s31, constructing the ground wall of the main body;
s32, constructing the crown beam;
s33, checking and accepting the foundation pit excavation;
s34, excavating the foundation pit in a vertical layering and longitudinal segmentation manner;
s35, excavating a first section of the foundation pit to form a bottom;
and S36, performing flow process according to the structure of the main body.
3. The soft geological foundation pit excavation construction method of the existing line station as set forth in claim 1, wherein the step S2 specifically includes:
s21, arranging monitoring points;
s22, monitoring the station hall layer of the operating line;
s23, monitoring frequency;
s24, monitoring, early warning and alarming;
and S25, automatically monitoring the station layer.
4. The soft geological foundation pit excavation construction method of the existing line station as set forth in claim 3, wherein the step S21 specifically comprises:
selecting a building in an influence range to carry out monitoring point arrangement, then arranging underground pipeline monitoring points, then arranging municipal road monitoring points, arranging surface monitoring points by combining the conditions of the building, the bridge, the underground pipeline and the road monitoring points, and then arranging the horizontal displacement of the pile top of the enclosure structure, the deformation measuring points of the pile body and the supporting axial force by combining the surrounding environment condition and the enclosure structure condition;
arranging measuring points of the surrounding environment and the building envelope system in the same section;
arranging the measuring points at the positions capable of reflecting construction so as to ensure the engineering safety state;
and arranging temporary monitoring points on the ground at the division lines of the driving lanes.
5. The soft geological foundation pit excavation construction method of the existing line station as set forth in claim 3, wherein the step S25 specifically comprises:
monitoring range;
monitoring a project;
automatic monitoring points of the platform are distributed;
carrying out real-time observation through a measuring robot;
and feeding back early warning information according to the measuring robot.
6. The soft geological foundation pit excavation construction method of the existing line station as set forth in claim 1, wherein the step S4 specifically includes:
according to the shape of the foundation pit and the excavation requirement, arranging a field control station and a pump station of the automatic axial force compensation system in a straight line along the edge of the foundation pit, adhering the arrangement positions of the field control station and the pump station to the principle of shortest line, and completing program debugging of equipment installation, a single system and a total system;
assembling the end of the steel support sleeve box and the steel support in advance, erecting the steel support according to the excavation progress of the foundation pit, installing a jack, setting a system pressure control value on a monitoring station according to the designed axial force, and finishing the step-by-step application of the designed pre-applied axial force; various initial values of monitoring data are collected for synchronous monitoring.
7. The soft geological foundation pit excavation construction method of the existing line station as set forth in claim 1, wherein the step S5 specifically includes:
s51, cutting and seam checking;
s52, carrying out high-pressure jet grouting on the pile;
and S53, stopping water at the leakage point.
8. The soft geological foundation pit excavation construction method of the existing line station as set forth in claim 7, wherein the step S53 specifically includes:
s531, performing double-liquid-slurry water stop treatment; according to the depth of the leakage position, grouting holes are punched in the earth surface on the outer side of the enclosure structure, high-pressure grouting construction is carried out, and when grouting slurry cannot be pressed into the leakage point, the grouting holes return slurry;
s532, polyurethane water stop treatment; aiming at the leakage point of the ground wall, the oil-based polyurethane is adopted for leaking stoppage and water stopping, the slurry immediately undergoes chemical reaction after meeting water, the viscosity of the slurry is gradually increased, finally water-insoluble gel is generated, carbon dioxide gas is generated at the same time, the slurry is diffused towards the periphery under the action of expansion force generated by the gas, the slurry is pressed into the pore, and the pore is filled compactly to realize sealing.
9. The excavation construction method for the soft geological foundation pit of the existing line station as claimed in claim 8, wherein the step S531 specifically comprises:
cleaning; finely checking and analyzing the leakage condition, determining the position and the distance of a grouting hole, cleaning a region needing construction, chiseling precipitates on the surface of concrete, and ensuring the surface to be clean;
drilling; drilling pressure relief holes along the periphery of the hole by using a drilling tool, wherein the diameter of a drill bit is 14mm, the drilling angle is less than or equal to 45 degrees, the drilling depth is less than or equal to 2/3 of the structural needle head, and the drill hole needs to penetrate through the main water leakage hole in an inclined mode;
burying a mouth; observing the pressure of the main water leakage hole, burying the grouting water stopping needle head by using the quick-drying plugging agent when the pressure of water flow is not high, and installing the expansion water stopping needle head on other water leakage holes respectively when the structure reaches certain strength and does not leak, screwing the expansion water stopping needle head by using a special inner hexagonal wrench, so that no gap exists between the periphery of the grouting nozzle and a drilled hole, no water leakage exists, and the expansion water stopping needle heads are also sequentially installed on the wall surface in case of slow seepage.
Grouting; using a high-pressure grouting machine to perform pressure test, and grouting polyurethane grouting liquid into the grouting holes under the condition that the pressure of the concrete structure is not exceeded;
disassembling a nozzle; and after the grouting is finished for 24 hours, removing or knocking off the exposed grouting nozzle after the grouting is confirmed to be leak-proof, and cleaning the solidified leaked grouting liquid.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115419075A (en) * | 2022-09-29 | 2022-12-02 | 中铁二十一局集团第五工程有限公司 | Super bridge deep foundation pit and construction method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102828517A (en) * | 2012-08-30 | 2012-12-19 | 中铁十三局集团第三工程有限公司 | Hierarchical control construction method of foundation pit excavation at entrance and exit of station |
| WO2013147652A2 (en) * | 2012-03-30 | 2013-10-03 | Общество с ограниченной ответственностью "Инженерное бюро Юркевича" | Metro station and method for constructing same |
| CN108256247A (en) * | 2018-01-25 | 2018-07-06 | 上海交通大学 | A kind of servo support system forced deformation computing method using amendment stiffness matrix |
| CN109706940A (en) * | 2019-02-27 | 2019-05-03 | 腾达建设集团股份有限公司 | Foundation pit servo support system setting method |
| CN109811769A (en) * | 2019-03-19 | 2019-05-28 | 腾达建设集团股份有限公司 | A kind of excavation method |
| CN110821922A (en) * | 2019-11-14 | 2020-02-21 | 江苏万川液压机械设备有限公司 | Sensitive servo monitoring compensation system for foundation pit horizontal supporting axial force and displacement load |
-
2021
- 2021-05-10 CN CN202110506693.1A patent/CN113152476A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013147652A2 (en) * | 2012-03-30 | 2013-10-03 | Общество с ограниченной ответственностью "Инженерное бюро Юркевича" | Metro station and method for constructing same |
| CN102828517A (en) * | 2012-08-30 | 2012-12-19 | 中铁十三局集团第三工程有限公司 | Hierarchical control construction method of foundation pit excavation at entrance and exit of station |
| CN108256247A (en) * | 2018-01-25 | 2018-07-06 | 上海交通大学 | A kind of servo support system forced deformation computing method using amendment stiffness matrix |
| CN109706940A (en) * | 2019-02-27 | 2019-05-03 | 腾达建设集团股份有限公司 | Foundation pit servo support system setting method |
| CN109811769A (en) * | 2019-03-19 | 2019-05-28 | 腾达建设集团股份有限公司 | A kind of excavation method |
| CN110821922A (en) * | 2019-11-14 | 2020-02-21 | 江苏万川液压机械设备有限公司 | Sensitive servo monitoring compensation system for foundation pit horizontal supporting axial force and displacement load |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115419075A (en) * | 2022-09-29 | 2022-12-02 | 中铁二十一局集团第五工程有限公司 | Super bridge deep foundation pit and construction method |
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