220 results about "Rock tunnel" patented technology

The invention relates to an intelligent soft rock tunnel surrounding rock deformation automatic monitoring and early warning system, and belongs to the field of tunnel construction safety monitoring. According to the system, multi-source data of surrounding rocks are synchronously acquired through a micron-sized laser displacement sensor, a fiber grating strain sensor, a pore water pressure sensor and a three-dimensional micro-seismic sensor array which are distributed; the edge calculation node fuses the data in real time and calculates the displacement rate, the strain gradient and the osmotic pressure coupling coefficient, and local early warning is triggered in combination with a dynamic threshold value; the cloud early warning platform predicts a deformation trend based on an LSTM-Transform fusion model, generates a multi-stage early warning signal through a risk grading engine, and is linked with the supporting equipment to regulate and control pressure; and meanwhile, a self-calibration device, an explosion-proof shell and a piezoelectric-thermal energy self-powered system are integrated. According to the method, closed-loop control from millimeter-level deformation sensing to active supporting can be achieved, and tunnel construction safety is remarkably improved.

The invention discloses a soft rock tunnel overexcavation backfill method, and relates to the technical field of tunnel construction.The soft rock tunnel overexcavation backfill method comprises the steps that a three-dimensional live-action image in a tunnel is scanned; establishing a three-dimensional live-action model according to the three-dimensional live-action image; establishing a digital twin model of the tunnel according to a design drawing; carrying out geometric intersection on the three-dimensional live-action model and the digital twin model to obtain geometric parameters of an overexcavation area; a concrete mold is subjected to 3D printing according to the geometric parameters of the overexcavation area; concrete is poured into the concrete mold, and a backfill body is formed; and the backfill body is backfilled to the overexcavation area. Due to the fact that the formed backfill body is tightly attached to the tunnel wall of the overexcavation area, the backfill precision is effectively improved, the construction quality is improved, the stability and the bearing capacity of the inner wall of the tunnel are enhanced, potential safety hazards are reduced, the concrete backfill work amount can be accurately controlled, the construction cost is reduced, and material waste is avoided.

The invention discloses a dynamic early warning method and system for soft rock tunnel extrusion large deformation catastrophe, and the method comprises the steps: building a soft rock tunnel surface reference model, carrying out the point cloud registration, updating the soft rock tunnel surface model, recognizing a deformation mode, adjusting a deformation mode threshold value, carrying out the apparent dynamic early warning, and carrying out the multi-scale compensation. Constructing a Bayesian catastrophe prediction network based on a control-state coupling mechanism to obtain a large-deformation dynamic catastrophe index, adjusting a threshold value of the large-deformation dynamic catastrophe index to perform internal dynamic early warning, performing multiple regression to obtain a damage mapping relation set, constructing a deformation feature vector, and performing dynamic early warning; and constructing a dangerous event prediction model based on semi-supervised learning, obtaining a dangerous event prediction result in combination with the destruction mapping relation set, and performing event dynamic early warning. The method not only can improve the precision of dynamic early warning of the soft rock tunnel extrusion large deformation catastrophe, but also has good interpretability, and can be directly applied to a dynamic early warning system of the soft rock tunnel extrusion large deformation catastrophe.

The invention relates to the technical field of tunnel supporting, in particular to a self-expanding pipe shed advance supporting system for a weak water-rich surrounding rock tunnel, which comprises a tunnel face stability identification module, a grouting effect extraction module, a component supporting adaptation module, a pipe shed expansion execution module and a surrounding rock instability early warning module. According to the method, a particle loose section is identified through the change trend of the void ratio of the tunnel face and the contact pressure, the waterstop coverage integrity is analyzed by combining the multi-dimensional comparison of the grouting diffusion range and the permeation speed, and the component adaptability is judged by extracting the anchoring depth of the component and the joint state information according to the design requirement; and the confining pressure change rate before and after expansion is collected to recognize a section with insufficient supporting force and mark a position needing to be processed, a tunnel face stability threshold value is constructed according to the displacement rate and the crack growth trend, accurate early warning of a risk section is achieved, and a supporting control closed loop integrating recognition, verification, adaptation, intervention and early warning is constructed.

The invention discloses a design method for anti-erosion tunnel parameters. The design method comprises the steps that tunnel environment information and a tunnel safety index range are acquired; determining a catastrophe risk of the tunnel based on the tunnel environment information; determining a tunnel structure parameter range based on the catastrophe risk of the tunnel; determining tunnel structure parameters based on the tunnel structure parameter range; determining tunnel safety indexes based on the tunnel structure parameters; and determining or adjusting tunnel structure parameters based on a comparison result of the tunnel safety index and the tunnel safety index range. According to the design method of the anti-erosion tunnel parameters, blindness and randomness of composite corrosion and erosion surrounding rock tunnel structure parameter values are avoided, the tunnel rigidity and durability are effectively guaranteed, and the later tunnel structure degradation risk is reduced.

The invention relates to small-section rock tunnel construction integrated equipment and a construction method. The small-section rock tunnel construction integrated equipment comprises a heading machine, a spraying mechanism, a supporting mechanism and a transport vehicle, wherein the spraying mechanism and the supporting mechanism are carried on a heading machine vehicle body, and the transport vehicle corresponds to a slag outlet of a cantilever type heading device. The concrete wet spraying device and the anchor rod drilling device are carried on the upper portion of the cantilever type heading machine body, and uninterrupted continuous operation of tunneling, deslagging and supporting can be achieved by reasonably arranging the positions and the operation sequence of the concrete wet spraying system, the anchor rod drilling device, the deslagging vehicle and the concrete mixer truck. And meanwhile, participation of constructors is effectively reduced, manpower is saved, and the efficiency and safety of tunnel construction are improved.

The invention discloses a deep learning-based large deformation prediction method for a high ground stress soft rock tunnel, and belongs to the field of tunnel engineering geological disaster prediction. By constructing a double-branch network architecture of'geological mode identification-deep learning prediction ', accurate prediction of large deformation of the tunnel is realized. The method comprises the following steps: firstly, collecting six qualitative indexes such as a rock mass structure, a weathering degree and an underground water condition and three quantitative indexes such as a strength-stress ratio, support rigidity and an equivalent hole diameter, performing encoding and normalization preprocessing, and respectively inputting the indexes into an upper-layer network and a lower-layer network; outputting probability distribution of six types of modes prone to large deformation, such as a weak homogeneous type mode and a block crack structure type mode; and the lower layer predicts the deformation and divides risk levels through a full-connection neural network based on the geological mode identification result and the quantitative index. According to the method, the complex coupling mechanism of large deformation of the high-crustal-stress soft rock tunnel can be fully reflected; adaptability prediction is realized for different geological modes.

The invention discloses a graded blasting construction method for a shallow-buried soft rock tunnel sensitive section. The method comprises the steps that measuring points are arranged in a tunnel chamber, a ground surface non-cavity section and a cavity section, and blasting vibration data are obtained; peak vibration velocity prediction models are established in a partitioned mode, an attenuation model is adopted in a chamber, a correction term is introduced into a non-cavity section of the earth surface to correct the attenuation model, and a multivariable model is established for the cavity section through dimensional analysis by integrating the horizontal distance, the elevation difference, the explosive quantity, the rock mass density and the tensile strength; determining a ground surface vibration velocity safety threshold, and quantifying a cavity vibration velocity amplification coefficient and an influence range thereof; based on the peak vibration velocity probability distribution and a preset safety level, establishing a safe dose prediction model and a safe range model; and dividing control areas according to the model, and implementing graded construction. According to the method, the vibration propagation law can be accurately described, the cavity amplification effect can be quantified, dynamic prediction of the blasting safety explosive quantity and range is achieved, and disturbance of blasting vibration to surrounding rock is effectively controlled through hierarchical management and control.

The present application relates to a kind of large section deep soft rock tunnel combined support system and construction method, the present application is combined with elastic shell theory and equivalent section method, a steel arch frame-grating combined support mode suitable for deep large section soft rock tunnel is proposed, the support rigidity of simply using steel arch frame or grid steel frame is overcome or supported, the disadvantage of lower in long-term large deformation unfavorable surrounding rock stability and deformation control, solve the problem that the stress of existing support structure is larger, the self-bearing capacity of surrounding rock cannot be fully exerted, cause material waste is serious, the safety factor of support structure is low, difficult to guarantee the stability of tunnel, and provide a simple and practical construction method for tunnel excavation and support.

The invention relates to the technical field of tunnel and underground engineering safety construction, in particular to a deeply-buried hard rock tunnel micro-seismic monitoring and segmented advanced blasting collaborative pressure relief method which comprises the steps that a pre-constructed micro-seismic monitoring system is arranged along the tunnel wall so as to collect and analyze seismic source parameters of a micro-seismic event; whether a preset early warning threshold value is exceeded is judged according to the judgment result; if yes, segmented advanced blasting pressure relief design is carried out based on the seismic source parameters of the micro-seismic event, so that blasting parameters are obtained; according to the blasting parameters, drilling wall protection and charging blasting are conducted on the tunnel hole wall, so that the blasted tunnel hole wall is obtained; the current surrounding rock response of the tunnel wall after blasting is observed, whether the current surrounding rock response exceeds a preset early warning threshold value or not is judged, if yes, it is judged that pressure relief is effective and tunneling is normal, and if not, blasting parameters are adjusted or pressure relief is supplemented in the next cycle. Therefore, the problems of passive rock burst risk early warning, poor pressure relief effect, extensive parameter control and the like under the high ground stress condition in drilling and blasting method construction of the deeply-buried hard rock tunnel are solved.

This utility model discloses a novel anchor bolt suitable for layered soft rock tunnels with different large deformation levels, relating to the field of soft rock tunnel support technology. It includes a first rod body, a second rod body, and an extension mechanism. The extension mechanism is disposed between the second rod body and the first rod body. The end of the first rod body is connected to an end cap, and a pad is disposed between the end cap and the first rod body. This utility model employs the aforementioned novel anchor bolt suitable for layered soft rock tunnels with different large deformation levels. The arrangement of the first and second rod bodies enhances the stability of the anchor bolt, resulting in more stable bonding anchoring force and higher pull-out resistance compared to simple metal anchor bolts, while also adapting to complex working conditions. The extension mechanism addresses the issue of easy deformation in soft rock, better utilizing the anchor bolt's support function. The material of the second rod body provides excellent adhesion and corrosion resistance, forming a high-strength anchoring interface, and its connection with the extension device enhances the stability of the device.

The application discloses a construction method for tunnel excavation and support in soft surrounding rock, which comprises the following steps: excavating the upper part of the upper portion to form an arch portion, forming a protective soil body at the middle position below the arch portion, and arranging an upper support along the wall surface of the arch portion; removing the protective soil body to form an upper pilot tunnel together with the arch portion, excavating the middle portion to form a middle pilot tunnel leading to the upper pilot tunnel, and arranging a middle support along the wall surface of the middle pilot tunnel; excavating the lower portion to form a tunnel bottom pilot tunnel leading to the middle pilot tunnel, arranging an inverted arch support in the tunnel bottom pilot tunnel, thereby completing the excavation and support of a tunnel unit; returning to the step of excavating the upper part of the upper portion to form an arch portion, forming a protective soil body at the middle position below the arch portion, and arranging an upper support along the wall surface of the arch portion until the excavation and support of each tunnel unit are completed, thereby completing the excavation and support of the whole tunnel. The construction method can effectively prevent the tunnel support from invading the secondary lining range.

The invention discloses a rapid energy dissipation protection system and method for TBM tunnel rockburst under high ground stress. The open type TBM tunnel is located in an incomplete supporting area in the front supporting operation L1 area. A steel arch frame is installed in a surrounding rock exposed area behind a shield, and the steel arch frame is arranged in a ring mode; a high-toughness energy dissipation net is laid on the surface of the steel arch frame, the high-toughness energy dissipation net is arranged between a surrounding rock exposed area and a guniting bridge in the longitudinal direction of the tunnel, and the annular arrangement range of the high-toughness energy dissipation net is an arch protection area; and the high-toughness energy dissipation net is fixed on the steel arch frame through a plurality of door-shaped clamps. The temporary energy dissipation net and the permanent steel frame are connected and formed, the energy dissipation net is circularly and inversely used for construction, and safe construction of the tunnel in an unfavorable geological section is guaranteed.

The invention discloses an advanced small pilot tunnel construction method for a high ground stress soft rock tunnel, belongs to the technical field of tunnel engineering construction, and adopts an excavation mode of combining a micro-step with a small pilot tunnel method and a support measure of combining a composite lining structure with a retractable U-shaped steel frame for temporary support. When crossing through a high-ground-stress soft rock stratum, by constructing the advanced small pilot tunnel, the effects of geological pre-judgment, risk pre-prevention and control, stress release in advance, support pressure relief, disturbance reduction and surrounding rock loosening circle reduction can be achieved. The surrounding rock deformation after the main tunnel is excavated is effectively reduced, so that the high-crustal-stress soft rock tunnel is efficiently and safely constructed.

The invention discloses a soft rock tunnel deformation monitoring and early warning method and system based on stress-displacement data, and the method comprises the steps: obtaining the continuous monitoring data of stress and displacement of each monitoring point through a sensor disposed at each monitoring point in a soft rock tunnel, and converting the continuous monitoring data into a behavior symbol sequence; according to the behavior symbol sequence and the spatial distribution of the monitoring points, calculating a structural response intensity value used for describing the structural response concentration degree and the evolution trend of any position in the soft rock tunnel at a certain moment, and forming a behavior density field; fourier transform or wavelet transform is carried out on the behavior density field in the time direction to obtain a frequency energy distribution map of the structural response, and the frequency energy of the structural response at a certain frequency in the frequency energy distribution map is extracted; and according to the deformation early warning value, the corresponding position is divided into the corresponding early warning grade.

The utility model provides a kind of weak broken surrounding rock tunnel model test system based on excavation compensation method, base inside is supported with the transparent simulation box by hole bottom plate, multiple broken surrounding rock simulation bodies are filled in simulation box, anchor rod and / or anchor cable are equipped on multiple broken surrounding rock simulation bodies;Triaxial dynamic loading system applies dynamic pressure to multiple broken surrounding rock simulation bodies;Double gradient grouting system is assembled in base bottom, real simulation tunnel construction disturbance, grouting reinforcement and support synergistic effect high simulation indoor test platform, solve traditional model test in grouting path control inaccuracy, support response process loss and multiple physical field monitoring incomplete and other technical problems, can be in indoor environment Real simulation coupling evolution process of tunnel surrounding rock and support structure in complex broken stratum, with Structure is reasonable, function is perfect, test repeatability is strong and other advantages.

The invention relates to the field of geological recognition, in particular to an axial chain type rockburst disaster-pregnant geological recognition method and device, and the method comprises the steps: obtaining micro-seismic monitoring data in the excavation process of a deeply-buried hard rock tunnel; according to the micro-seismic monitoring data, identifying the axial chain type rockburst disaster-pregnancy area to obtain a disaster-pregnancy area range; calculating the normal vector of the fracture surface according to the disaster-pregnant area range and the micro-seismic monitoring data; establishing a parameter system and constraint conditions required by ST-DBSCAN clustering according to the normal vector of the fracture surface and the micro-seismic monitoring data; sT-DBSCAN clustering processing is carried out according to the required parameter system and constraint conditions, and a micro-seismic event cluster reflecting a potential rock mass structural plane is obtained; and performing three-dimensional reconstruction processing on a rock mass structure network according to the micro-seismic event clustering cluster to obtain a reconstructed three-dimensional geometric model of the axial chain type rockburst disaster-pregnant geology. According to the axial chain type rockburst disaster-pregnant geology three-dimensional geometric model and the construction method thereof, accurate description of a hidden rock mass structure and effective advanced early warning of a rockburst risk are realized.

The utility model relates to the technical field of shield tunneling machines, in particular to a cutter conveying device and a double-shield TBM. The cutter conveying device comprises a first transferring mechanism, a second transferring mechanism, a conveying rail, a first automatic conveying vehicle and a cutter conveying beam. The first transfer mechanism is used for being installed on a segment assembling machine, and the cutter conveying beam is used for being installed on a main drive of a cutter head. The second transfer mechanism is movably mounted on the cutter conveying beam and comprises a second automatic transport vehicle and a driving part for driving the second automatic transport vehicle to move along the cutter conveying beam; the transport track is used for being installed on the inner wall of the shield body and located below the first transfer mechanism and the second transfer mechanism, and the first automatic transport vehicle is installed on the transport track in a matched mode. The technical problem that in the prior art, unmanned operation and full mechanization cannot be achieved in the tool conveying process when tools of a full-section hard rock tunnel boring machine are replaced is solved.

The invention discloses a surrounding rock grade evaluation method and platform based on multi-parameter feature fusion, and belongs to the technical field of soft rock tunneling, and the method comprises the steps: carrying out the information collection of surrounding rock characteristics, and obtaining a surface mechanical feature parameter, an internal structure feature parameter, a dynamic response feature parameter and a support feedback feature parameter; mapping the collected parameters to a four-dimensional feature space to obtain a four-dimensional feature vector X; constructing a scratch mechanical characteristic curve, a sound wave integrity characteristic curve, a drill bit dynamic response curve and a support force feedback curve; performing feature quantification on each curve by adopting machine learning, and constructing a surrounding rock grade evaluation model; on the basis of a surrounding rock grade evaluation model, grade evaluation is conducted on surrounding rock geology, the cutting depth is automatically optimized according to the grading result, drill bit types are switched, dynamic compensation of supporting pressure is achieved, millisecond-grade dynamic grading from plasticity to a brittle failure mode is achieved, construction risks under complex geological conditions are greatly reduced, and operation efficiency is improved.

The invention relates to the technical field of tunnel construction, in particular to a full-section construction method and a supporting structure of a soft rock tunnel under the high ground stress condition, and the construction method comprises the following steps: S1, closing a tunnel face, driving a pull rod into a rock stratum in front of the tunnel face from the tunnel face, and anchoring the pull rod to the rock stratum in front of the tunnel face; s2, the tunnel is excavated forwards, an anti-collapse frame is installed on the newly excavated tunnel face, the anti-collapse frame is connected with the pull rod, and the anti-collapse frame is used for preventing the newly excavated tunnel face from collapsing; and S3, a supporting structure is constructed for the newly excavated tunnel. According to the scheme, the problem that the construction efficiency is low due to the fact that the tunnel face collapses easily under the high ground stress condition and multi-step construction is needed can be solved, the construction efficiency can be greatly improved, disturbance of segmented excavation to surrounding rock is reduced, primary support can be closed into a ring at a time, the support time can be greatly shortened, the primary support continuity is improved, and the construction cost is reduced. The deformation of the primary support is reduced, and the safety risk of secondary excavation caused by arch change due to the deformation of the primary support is greatly reduced.

The invention discloses a soft rock tunnel deslagging method, and relates to the technical field of soft rock tunnel construction.The soft rock tunnel deslagging method comprises the steps that rock mass information of a soft rock tunnel is obtained; according to the rock mass information, a plurality of different deslagging units are arranged on the tunnel face of the soft rock tunnel; according to the rock mass information, rock mass form distribution results of the multiple different deslagging unit soft rock tunnels are obtained; according to a rock form distribution result, a deslagging sequence is obtained; pre-loosening the rock mass corresponding to each deslagging unit according to the deslagging sequence to form a pre-loosened rock mass; and the pre-loosened rock mass is crushed, cleared and transported, and deslagging of the soft rock tunnel is completed. According to the method, the differentiated deslagging units are set by obtaining the rock mass information, the deslagging sequence is determined in combination with rock mass form distribution, targeted pre-loosening treatment is implemented, and the deslagging efficiency and construction safety of the soft rock tunnel are improved.

The application relates to the technical field of tunnel engineering disaster prediction, and discloses a soft rock tunnel large deformation prediction method based on a particle swarm optimization neural network, which comprises the following steps: selecting geological construction characteristic parameters such as water content of surrounding rock and construction methods as input factors, and establishing a qualitative index and quantitative value mapping; based on orthogonal test design and numerical simulation, engineering sample data sets are constructed and normalized; subsequently, the initial connection weight and bias of an error back propagation neural network are globally iteratively optimized by using a particle swarm optimization algorithm, so that optimal initial values are obtained by taking network errors as fitness values; finally, data training is carried out to generate a mature model, and a predicted deformation value is output and combined with a double check mechanism to carry out engineering early warning. The application solves the problems that traditional neural networks are slow in convergence and prone to falling into local optimization due to random parameter initialization, and effectively improves the prediction accuracy of soft rock tunnel large deformation and the reliability of engineering early warning.

The invention discloses a weak surrounding rock tunnel face instability mechanism experiment device and method. A stratum environment simulation system is arranged above a model box system, and a tunnel excavation simulation system is installed in the model box system; in the stratum environment simulation system, a base of a hydraulic jack is fixedly arranged on a force transmission plate, a counter-force beam is fixedly arranged on the model box system, and a telescopic rod of the hydraulic jack is rotationally connected with the counter-force beam. According to the invention, a weak surrounding rock tunnel face instability mechanism reduced scale model test is carried out, a hydraulic jack is used for applying a load acting on a force transmission plate, the force transmission plate is used for transmitting the load to a position above a stratum so as to simulate surrounding rock overlying loads at different burial depths, and gradual unloading is carried out through a displacement control method so as to realize tunnel face instability failure whole process simulation. The stratum deformation evolution rule and the geometrical characteristics of a plastic instability area in the tunnel instability state are researched, and the method can be used for simulating the stability and instability characteristics of tunnel faces with different section forms, excavation forms and using functions.

A water pressure blasting similar test model and method suitable for a class IV surrounding rock tunnel, comprising a monitoring area model and a surrounding rock area model arranged in front and back. The monitoring area model comprises a cylindrical frame A, which is internally provided with a dust monitoring device; the surrounding rock area model comprises a cylindrical frame B, and the frame B can be tenon jointed with the frame A. The frame B is internally filled with simulated surrounding rock, and the outside of the simulated surrounding rock is connected with a pressurizing device. The model further comprises a gas blasting device, a plurality of simulated blast holes are formed on the simulated surrounding rock, and the gas blasting device is connected with the simulated blast holes through a gas conveying pipe; the simulated blast holes are further filled with water bags and dust suppressants. The gas blasting device is used to replace black powder blasting, which has high safety and improves the service life of the model. The simulated surrounding rock similar to the class IV surrounding rock is filled, and the simulated surrounding rock is pressurized by using the pressurizing device, which is more similar to the actual situation.

The application provides a method for determining the construction timing of loose soft rock tunnel lining, and belongs to the technical field of loose soft rock tunnel lining construction. The method comprises the following steps: arranging a surrounding rock deformation monitoring section along the axial direction of the tunnel, continuously collecting displacement stress and water seepage data to form a time series data set, inputting the time series data set into a stress release prediction model to output surrounding rock deformation prediction values and stress release stability scores, performing spatial variability risk assessment to calculate the dispersion coefficient of surrounding rock parameters when the stability score is greater than a threshold value and the deformation rate meets the conditions, generating a lining construction permission signal when the dispersion coefficient is less than a threshold value, maintaining real-time monitoring during the pouring process and stopping pouring and re-evaluating when the deformation rate suddenly increases, thereby solving the technical problem of difficulty in accurately determining the construction timing of loose soft rock tunnel lining.

The present application relates to the technical field of tunnel construction, in particular to a soft rock stratum tunnel construction support trolley, which comprises a portal assembly, a support assembly and a flexible support system. The lower end of the portal assembly is provided with a walking mechanism. The support assembly is provided with a plurality of support arches, and the outer peripheral wall of the support arches is provided with a receiving groove. Each support arch is composed of a plurality of arch beams and two arch feet, and the arch beams abut each other through the inclined surfaces on both sides. The flexible support system is provided with an air bag unit, which is received in the receiving groove during walking and is inflated and exposed outside the support arch during supporting, actively adapting to the surrounding rock contour and exerting a buffer pressure. The present application realizes rapid deployment and emergency support, effectively stabilizes the soft rock stratum, and creates safe conditions for the construction of permanent support.

The application discloses a high-stress soft rock tunnel large deformation prediction method based on deep learning, and belongs to the field of tunnel engineering geological disaster prediction. Through the construction of a double-branch network architecture of "geological pattern identification-deep learning prediction", the accurate prediction of tunnel large deformation is realized. First, six qualitative indexes such as rock mass structure, weathering degree and underground water condition and three quantitative indexes such as strength stress ratio, support stiffness and equivalent hole diameter are collected, and after coding and normalization preprocessing, they are respectively input into the upper and lower networks: the upper layer adopts a convolutional neural network to identify the surrounding rock geological pattern, and outputs the probability distribution of six types of large deformation modes such as soft homogeneous type and block structure type; the lower layer predicts the deformation amount and divides the risk grade through a fully connected neural network based on the geological pattern identification result and the quantitative index. The application can fully reflect the complex coupling mechanism of high-stress soft rock tunnel large deformation; and adaptive prediction is realized for different geological patterns.

The invention provides a temporary inverted arch and an inferior surrounding rock tunnel construction method.The temporary inverted arch comprises an arch frame body, and the arch frame body comprises a plurality of steel frameworks linearly arranged in the tunnel excavation direction and connecting ribs connected among the steel frameworks; the two ends of each steel framework are detachably connected with a primary supporting steel arch on the inner wall of the tunnel, and a concrete layer is poured on an arch body. The inferior surrounding rock tunnel construction method comprises the steps that after a core soil section is excavated, the temporary inverted arch is constructed above a step section; the step section is excavated, and the primary support is constructed, so that the temporary inverted arch and the primary support after the annular arch section is excavated can be quickly closed to form a group of complete temporary stress rings, and the stress rings can effectively bear surrounding rock pressure from the periphery, uniformly transfer loads and remarkably inhibit arch crown sinking and side wall convergence; therefore, surrounding rock deformation is controlled to the maximum extent, and construction safety is guaranteed.

The utility model relates to the technical field of shield construction equipment, and discloses an auxiliary device for the starting stage of an open-type hard rock tunnel boring machine, which structurally comprises a shield body stepping seat, a supporting shoe external expansion frame, a saddle stepping base, trolley stepping supporting legs, a braiding climbing frame and a clamping rail synchronous pushing device, and is simple in structure, convenient to operate and reusable. The supporting shoe external expansion frame tightly supports the stepping hole wall, a fulcrum and balance torque are provided for cutterhead tunneling, the cost is lower compared with the mode that an external propelling device is used for providing jacking force for cutterhead propelling, installation is faster, and operation is easy. In the stepping process, the arrangement climbing frame located at the tail can enable the service arrangement to climb onto the trolley lifted by the trolley stepping supporting legs conveniently, and then the muck transportation task is completed.

The invention discloses an excavation and support method and system for a seriously extruded and deformed hole section of a soft rock tunnel, and relates to the technical field of excavation and support construction of underground cavities. The method comprises the steps of obtaining a surrounding rock state, and determining step length and reserved deformation according to the surrounding rock state; surrounding rock deformation is restrained and underground water permeation is blocked based on the reserved deformation; a top arch advance support system is constructed, a large pipe shed and a small guide pipe are installed on the periphery of a tunnel top arch before excavation, and advance consolidation grouting is carried out; an excavation supporting operation space is determined according to the length of the steps, and rigid supporting construction is carried out after the tunnel is excavated according to the step-by-step short footage; after the tunnel is excavated, H-shaped steel supports are erected on a top arch, side walls and a bottom plate, and feet-lock bolts are installed; after the feet-lock bolts are completed, primary support reinforcement is carried out; and when the primary support is completed and the deformation of the surrounding rock tends to a preset variable rate threshold value, deepening a system drainage hole in the tunnel surrounding rock and carrying out radial consolidation grouting. According to the method, primary support and surrounding rock deformation are coordinated, and the safety of tunnel construction is improved.