34results about How to "Excavation process safety" patented technology

The invention discloses a construction method for enabling a shallowly buried and darkly excavated tunnel to pass through a cottage area. The construction method comprises the following steps: excavating a tunnel hole of the constructed shallowly buried and darkly excavated tunnel from back to front through a step excavation process, and performing preliminary bracing on the tunnel hole formed by excavating from back to front in an excavating process, wherein the tunnel hole consists of an upper guide hole and a lower guide hole positioned right below the upper guide hole, the rear part of the tunnel hole is connected with a vertical well, the preliminary bracing structure of the tunnel hole comprises a plurality of grating steel frameworks for supporting the tunnel hole from back to front, a layer of bar-mat reinforcement suspended on the inner wall of the tunnel hole and a concrete layer jetted on the inner wall of the tunnel hole. The process for excavating the tunnel hole of the shallowly buried and darkly excavated tunnel comprises the following steps: I, excavating the initial segment of the upper guide hole; II, excavating the initial segment of the lower guide hole; III, synchronously excavating the upper and the lower guide holes. The construction method disclosed by the invention is simple in step, reasonable in design, convenient in construction, good in construction effect, capable of simply completing the construction process of the shallowly buried and darkly excavated tunnel that passes through the cottage area, and safe and reliable in a construction process.

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 construction method for a tunnel in an upper-soft and lower-hard stratum. When constructing any one of the tunnels to be constructed, the steps include: 1. Excavation of the rear tunnel section and initial support construction; 2. Tunnel at the junction Reinforcement of the surrounding rock of the section and temporary reinforcement of the rear tunnel section; 3. The removal of the temporary support of the tunnel arch; 4. The forward movement of the shield machine and the construction of the second lining of the tunnel; 5. The construction of the shield. The invention is reasonable in design, simple in construction and good in use effect. The structure stability of the rear tunnel section is ensured through the temporary support of the tunnel arch, and the surrounding rock of the tunnel section at the junction is repaired by combining surface grouting reinforcement with internal reinforcement. Effective reinforcement can effectively improve the mechanical properties of the surrounding rock, effectively ensure the safe construction of the tunnel, and effectively reduce the ground subsidence caused by excavation; after the reinforcement of the surrounding rock in the tunnel section at the junction is completed, the temporary support of the tunnel arch will be carried out. Remove and move the shield machine forward to construct the front tunnel section, the construction process is safe and reliable.

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.