31results about How to "The initial support process is easy" patented technology

The invention discloses a large-section tunnel excavation and support construction method for crossing a soil-rock boundary stratum. The method comprises the following steps of first, upper middle step excavation and initial support construction, specifically, carrying out upper step excavation and initial support construction on a construction tunnel by a plurality of excavation sections from rear to front, and when any excavation section is subjected to upper step excavation and initial support construction, the process comprises the following steps of measuring pay-off, drilling and blasting construction, excavation and initial support of an upper cave, and excavation and initial support of a middle cave; second, lower step excavation and initial support construction; and third, carrying out secondary lining construction. The method is reasonable in design, simple and convenient to construct and good in use effect, the upper blasting area in the upper step and the middle blasting area on the middle step are separately subjected to blasting zone division, the arrangement position of each shot hole in each blasting zone is defined, the collapse of a tunnel face or the collapse ofa vault caused by large vibration generated by blasting when one-time loading of the large section is excessive can be effectively prevented, the safety and reliability of the tunnel excavation process are ensured, and the stability of the tunnel structure is ensured.

The invention discloses a method for beyond-limit arch replacing construction during preliminary bracing of a large-section loess tunnel. The method includes the steps of firstly, conducting radial grouting reinforcement on an arch wall, wherein radial grouting reinforcement is conducted on an arch replacing required section where arch replacing is required in the constructed loess tunnel from back to front; and secondly, conducting arch replacing construction, wherein a reinforced preliminary bracing structure in the arch replacing required section is detached, and preliminary bracing construction is conducted on the arch replacing required section synchronously in the detaching process. The method is simple in step, reasonable in design, simple in construction and good in use effect; theradial grouting reinforcement is conducted on the arch wall to reinforce the arch wall of a tunnel hole first, so the structural stability of the tunnel in the arch replacing process is ensured; segmented reinforcing is conducted on the preliminary bracing structure of the tunnel through a plurality of sleeve arch units for a reinforced sleeve arch in the arch replacing required section, so detaching is convenient; and moreover, the sleeve arch units are complementary and together improve the supporting force, so the adverse effects on the structural stability of the tunnel in the detaching process of each sleeve arch unit can be effectively reduced, and the safety and reliability of the arch replacing construction process are ensured.

The invention discloses a tunnel pre-reinforcement and excavation construction method crossing the earth-rock boundary stratum, comprising the following steps: 1. Pre-reinforcement by precipitation; 2. Excavation construction of the rear tunnel section; 3. Excavation construction of the middle tunnel section; 4. 1. The excavation construction of the front tunnel section; the middle tunnel section and the front tunnel section are all three-step synchronous excavation tunnel sections; in step 2, step 3 and step 4, the excavation process is carried out from back to front, Simultaneously carry out initial support for the excavated tunnel hole from back to front. The invention is reasonable in design, easy in construction and good in use effect. Firstly, the underground water level is lowered through precipitation pre-reinforcement and the surrounding rock is effectively reinforced, and then a suitable drilling and blasting method is selected according to the positional relationship between the soil-rock interface and the tunnel hole, and three steps are adopted. The simultaneous excavation method for blasting excavation can ensure the safety and reliability of the excavation process of the tunnel passing through the soil-rock boundary stratum, and can ensure the stability of the tunnel structure.

The invention discloses a pre-reinforcement and excavation construction method for a tunnel entrance segment of a loess tunnel passing through a slip mass. The method comprises the following steps offirstly, tunnel body soil layer pre-reinforcement, secondly, tunnel entrance construction of the tunnel, thirdly, excavation and preliminary bracing construction of the reinforced tunnel segment, andfourthly, excavation and preliminary bracing construction of the rear tunnel segment. By means of the method, design is reasonable, construction is simple and convenient, and the use effect is good; before excavation, cemented soil stirring piles are adopted for carrying out reinforcement treatment on the loess stratum of the construction area where the tunnel entrance segment of the tunnel is located in advance, the reinforcement length and reinforcement depth are effectively limited, loose soil of the tunnel body of the tunnel is solidified in advance, it is ensured that the construction process of the tunnel entrance segment of the tunnel passing through the slip mass is safe and reliable, and the structure of the tunnel entrance segment, formed through construction, of the tunnel is stable; and meanwhile, a three-step excavation method is adopted for excavating the tunnel entrance segment of the tunnel, it can be ensured that the excavation process of the tunnel entrance segment ofthe tunnel passing through the slip mass is safe and reliable, and the influence on stability of soil layers around the tunnel is small.

The invention discloses a construction method of a soil-stone boundary tunnel passing through loess valleys. The construction method comprises the following steps of 1, precipitation pre-reinforcement; 2, excavation construction of a rear side tunnel section; 3, excavation construction of a middle tunnel section; and 4, excavation construction of a front side tunnel section, wherein the middle tunnel section and the front side tunnel section are three-step synchronous excavation tunnel sections; and in the excavation process from back to front in the step 2, the step 3 and the step 4, primarysupport is synchronously carried out on the excavated tunnel from back to front, and secondary lining of the tunnel is constructed on the inner side of the constructed and formed tunnel primary support structure from back to front. The construction method is reasonable in design, simple and convenient to construct and good in use effect, the underground water level is reduced through precipitationpre-reinforcement, surrounding rock is effectively reinforced, then blasting excavation is carried out in a three-step excavation mode, so that the excavation process of the soil-stone boundary tunnel passing through the loess valleys can be ensured to be safe and reliable, and the stability of the tunnel structure can be ensured.

The invention discloses a large-section tunnel stability control construction method capable of passing through an earth and stone boundary stratum, and an earth and stone interface is positioned in an upper hole of a constructed tunnel. During excavation construction on the constructed channel, the large-section tunnel stability control construction method comprises the following steps: I, upperand middle step excavation step: performing upper and middle step excavation construction on the constructed tunnel in multiple excavation sections from rear to front, wherein the process of performing upper and middle step excavation construction on any excavation section comprises surveying and setting out, drilling and blasting construction, upper hole excavation and middle hole excavation; andII, lower step excavation construction. The large-section tunnel stability control construction method is reasonable in design, is simple and convenient in construction, is good in use effect, separately performs blasting region division on an upper blasting region in an upper step and a middle blasting region on a middle step, defines layout position of each blast hole in each blasting region, can effectively prevents tunnel face collapse or arch crown collapse caused by relatively great vibrations generated by blasting while large-section once explosive load is too great, ensures a safe andreliable tunnel excavation process, and can ensure a stable tunnel structure.

The invention discloses a construction method for a water-rich loess tunnel passing through a loess flushing valley. The constructed loess tunnel includes a tunnel entrance section, a flushing valley shallow-buried tunnel section and a front tunnel section. The flushing valley shallow-buried tunnel section is connected to the tunnel entrance Between the entrance section and the front tunnel section; during the construction of the loess tunnel to be constructed, the steps include: 1. construction of the entrance section of the tunnel; 2. construction of the tunnel section buried shallowly in the valley; The method of the invention has the advantages of simple steps, reasonable design, convenient construction, and good application effect. According to the different formations of the tunnel entrance section, the shallow-buried tunnel section and the front tunnel section, a reasonable advanced reinforcement method and a tunnel base reinforcement method are selected for the tunnel. The soil reinforcement can effectively ensure the safety and reliability of the excavation process of the rich water large-section loess tunnel, and can effectively improve the stability of the excavated and formed tunnel hole.

The invention discloses a construction method of a shallow-buried tunnel in a loess gully. The construction method comprises the following steps: 1, grouting a sleeve valve pipe for advancing reinforcement: carrying out sleeve valve pipe grouting for reinforcement on a stratum in the construction area of the constructed shallow-buried tunnel; 2, carrying out tunnel excavation and preliminary bracing; and 3, constructing a second lining. The construction method is simple in step, reasonable in design, simple and convenient in construction and excellent in using effect; the sleeve valve pipe isadopted and a plurality of rows of grouting holes are adopted to grout the reinforced stratum for reinforcement; the range of the reinforced stratum is specifically limited; both the tunnel hole bodyand the tunnel base can be reinforced, and the reinforcement effect is reliable; the shallow-buried tunnel construction method is particularly suitable for advancing reinforcement and excavation construction of the shallow-buried tunnel section which is positioned in a loess gully and is adjacent to an earth and stone interface, and the earth's surface of the shallow-buried tunnel is a silting-upland layer. The construction method can effectively ensure safety and reliability of the excavation process of the shallow-buried tunnel in the loess gully, can effectively improve the stability of the excavated tunnel hole and can effectively improve the bearing force of the tunnel base.

The invention discloses a construction method for a loess tunnel passing through a landslide body. The tunnel entrance section and the tunnel exit section are constructed at the same time; while the tunnel entrance section and the tunnel exit section are being constructed, the inclined The entrance section of auxiliary construction of well and the exit section of auxiliary construction of inclined shaft shall be constructed. The invention is reasonable in design, simple in construction and good in use effect. Before excavation, cement-soil mixing piles are used to reinforce the loess layer in the construction area where the entrance section of the tunnel is located, and effectively limit the length and depth of reinforcement. The loose soil in the tunnel body is consolidated to ensure the safety and reliability of the construction process at the entrance section of the tunnel passing through the landslide. The construction process of the loess tunnel can be quickly completed, and the stability of the excavated tunnel hole can be effectively improved.

Disclosed is a construction method for a tunnel passing through a high-angle thrust water-rich and sand-rich fault, comprising the following steps: 1, performing the preliminary excavation and the supporting construction of a rear-side tunnel section (3); 2, performing the synchronous excavation and the supporting construction of the rear-side tunnel section (3) and a drainage cave body of a drainage cave (2); 3, performing the synchronous excavation and the supporting construction of the rear-side tunnel section (3), the drainage cave body of the drainage cave (2), and a rear-side detouring heading pit (1) section; 4, performing the excavation and the supporting construction of a front drainage cave (2) body, a front heading pit section, and a central tunnel section (5); and 5, performing the excavation and the supporting construction of a front-side tunnel section (4). The water on the upper wall of the fault is drained by means of a high-level drainage cave between a tunnel main cave and a detouring heading pit, and the auxiliary drainage is performed by means of the detouring heading pit and the fault condition in front of a tunnel face of the main cave is explored in advance, thereby ensuring the construction safety of each tunnel face. The method employs a three-step method for the excavation of the tunnel main cave, employs double preliminary supporting structures for the full-section supporting of a tunnel cave after excavation, can ensure the safety of the tunnel structure later, and shortens the construction cycle.

The invention discloses an excavation and supporting method for a tunnel crossing a high-angle thrust water-rich and sand-rich fault. A circuitous pilot tunnel and a drainage tunnel are arranged on asame side of a tunnel main hole. When excavation and supporting construction is carried out on a construction tunnel, the excavation and supporting method for the tunnel crossing the high-angle thrustwater-rich and sand-rich fault comprises the steps that 1, preliminary excavation and supporting construction is carried out on a rear side tunnel segment; 2, synchronous excavation and supporting construction is carried out on a rear side tunnel segment and a drainage tunnel body of the drainage tunnel; 3, the synchronous excavation and supporting construction is carried out on the rear side tunnel segment, the drainage hole body of the drainage tunnel and a rear side circuitous pilot tunnel segment; 4, the excavation and supporting construction is carried out on a front drainage tunnel body, a front pilot tunnel segment and a middle tunnel segment; and 5, the excavation and supporting construction is carried out on a front side tunnel segment. According to the excavation and supportingmethod for the tunnel crossing the high-angle thrust water-rich and sand-rich fault, the steps are simple, design is reasonable, construction is simple and convenient, the using effect is good, the tunnel hole is excavated by adopting a three-step method, full fracture surface supporting is carried out on the tunnel hole by adopting a double-layer preliminary supporting structure after excavation,and the safety of a later tunnel structure can be ensured.