Excavating method for jump-digging of double-side wall guide pit combined arch part of tunnel

Technical Field

The present invention relates to tunnel construction method, in particular for large SPAN combined pilot double sidewall of the tunnel arches hop-down.

Background Art

Excavation is 1st procedure the construction of tunnels, the tunnels in the excavation process, the stability of the adjacent rock of, in addition to the surrounding geological conditions of the tunnel and grouting, associated assister other than pre-support measures, the excavation of the tunnel section are also directly affect of the method, particularly for large SPAN, large cross-section tunnel, its excavation step more, excavation step results in frequent stress change, thereby causing a large scale tunnel around the plasticised, more easy to generate soil limit damage.

The construction of the tunnel works is an important criterion of quality and the stability of the rock to settling of the earth's surface, a large amount of engineering practice experience has shown that, in response to the size and the shape of a tunnel section, surrounding rock geological conditions of construction, supporting measures for construction period, the length of the work area, mechanical equipment capacity, comprehensive analysis of the economic and other related factors, the appropriate tunnel excavation method, excavation can effectively improve the influence of the surrounding rock stability, reducing the tunnel excavation caused by settling of the earth's surface. The current method of digging for full section are the main method, the subsection terrace cultivationexcavates the law and, in soft stratum of the large cross-section tunnel, because the full cross-section method of excavation section area of the one step method the support structure is too large and long time of closing of the two kinds of this method of excavating rock is very difficult to control stably and the settling of the earth's surface. Therefore, in the weak formation in the large cross-section tunnel excavation the subsection excavation method, mainly comprises an annular core indigenous reserved of excavation, double sidewall of the pilot tunnel method, next door law and the like in, these construction method for the stable rock although, reduce the sedimentation in progress, but in its construction to the step by step by opening backward to carry out the tunnel the soil excavation construction, the stress concentration phenomenon that the opening is obviously, complex stress, does not take into account the effect of the soil excavation of the tunnel space, is not conducive to stable rock.

Content of the invention

The purpose of this invention is for large cross-section of tunnel excavation method, provides a tunnel double sidewall of the pilot tunnel with jump arches dug excavation method, the general principles of the method of the first wall is arches the law , i.e. the double-side wall and pilot after the completion of the first, a first side wall of the lock to the secondary lining, and then the soil excavation arch blocks, the first support structure requirements, pouring arches b lining concrete. Excavation tunnel excavation archesguide holearches at first, from the opening to leave guide hole the two sides of the bottom of the excavation, a early archesarches operation immediately after the support structure of the second lining concrete, from the inside to the outside of the long SPAN arches gradually complete excavation of the tunnel structure.

The Purpose of the invention completed by the following technical scheme:

A tunnel double sidewall of the pilot tunnel with jump arches dug excavation method, used for large SPAN, large cross-section tunnel, characterized in that the stated method, firstly the two sides of the tunnel excavation is located in the side wall of the part of the pilot, after the tunnel excavation of soil arches , its steps are: first excavation tunnel arches guide hole; the opening left after arches from the guide hole to the position at the bottom of the excavation depth of the two sides of the tunnel excavation is located on both sides of the tunnel side wall pilot arches ; finally completed progressively from the inside to the outside of the tunnel excavation arches.

The side wall pilot sub-blocks, the excavation is completed one by one, and for temporary support structure, the two side walls of each side of the pilot tunnel is excavated along the longitudinal direction between the block pilot must have certain wrong distance , the construction of the wrong distance.

arches hole after the excavation of pilot tunnel, left and right sides of the excavation after the temporary support erection of, Provisional cross laid at the bottom, and then to the bottom of the guide hole from arches excavation arch side of the two sides of the pilot, constructing its archesguide hole and the supporting structure and the bottom of the two sides of the pilot side wall of the second lining concrete lining, treats arches side wall of the supporting structure and the supporting structure of the, two side walls of the pilot sub-temporary support structure.

Then progressively completed from the inside to the outside of the tunnel excavation of soil arches , and remove the guide hole lateral temporary support with the Provisional connecting struts.

The advantage of this invention lies in full consideration of the large SPAN of the tunnel excavation arches space effect, the stress concentration of the excavated section is reduced, thereby facilitating the surrounding rock stability, excavation of rock and to reduce the disturbance caused by the deformation. The method can control large cross-section tunnel excavation from the ground subsidence the larger, the excavation hole firstarches at the same time from the guiding of the guiding hole and internal to the two sides of the excavation of the pilot tunnel sidewall archesexcavated surface method can be increased, improving excavating efficiency save the construction period.

Description of drawings

Figure 1 is schematic diagram of the pilot tunnel is excavated on side hole ;

Figure 2 is schematic diagram of the pilot tunnel is excavated in side hole ;

Figure 3 is schematic diagram of the pilot tunnel is excavated under side hole ;

Figure 4 is schematic diagram of the guiding arches digging open;

Figure 5 of the side wall for the moulding of concrete schematic diagram of the second substrate;

Figure 6 in the side of the excavation of the pilot tunnel at the bottom of the pilot tunnel arches schematic diagram;

Figure 7 arches side of the opening for the excavation of the pilot tunnel schematic diagram of the part;

Figure 8 is schematic diagram of the core of the upper part of the soil excavation;

Figure 9 is schematic diagram of the core at the lower part of the soil excavation;

Fig. 10 schematic diagram for tunnel excavation is completed;

Figure 11 the design of this invention three-dimensional schematic diagram of the digging hop arches ;

Figure 12 is a design of this invention to jump arches digging plane schematic diagram.

Mode of execution

The following binding with photos by embodiments of the present invention, and other related design features is further detailed description, for the understanding of the technical personnel in the same industry:

With photos 1-12 middle-grade 1-20 on the left side represents the pilot tunnel 1, on the right side of the pilot tunnel 2, in the left side of the pilot tunnel 3, in the right side of the pilot tunnel 4, left side of the pilot tunnel 5, right side of the pilot tunnel 6, in arches of the pilot tunnel 7, arches side of the pilot tunnel 8, upper nuclear subsoil 9, lower nuclear subsoil 10, side of the initial supporting of the pilot tunnel 11, measured the pilot tunnel to temporary support 12, cross connection 13, of the pilot tunnel in the upright post 14, the initial supporting arches 15, the initial supporting of the arch 16, the secondary lining of the side wall 17, invert the secondary lining 18, the pilot tunnel in the cross-brace 19, the secondary lining arches 20.

As shown in Figure 1-10, this embodiment is directed to a large-SPAN tunnel is finger-SPAN ratio less than 0.8 and greater than the SPAN of the tunnel 10 meter

The following construction procedure for sequentially:

Figure 1 the shown schematic diagram of the pilot tunnel is excavated side hole. On the left side of the excavation of the pilot tunnel 1 and on the right side of the pilot tunnel 2, the initial supporting the pilot tunnel shi Zuoce 11, side of the pilot tunnel temporary support 12 (that is, partition wall), corner and 13.

Fig. 2 shown in schematic diagram of the pilot tunnel is excavated side hole. In the left side of the excavation of the pilot tunnel 3 in the right side of the pilot tunnel and 4, the initial supporting the pilot tunnel shi Zuoce 11, side of the pilot tunnel temporary support corner 12 and 13.

Figure 3 is shown the schematic diagram of the pilot tunnel is excavated side hole. The left side of the excavation of the pilot tunnel under 5 and right side of the pilot tunnel 6, the initial supporting the pilot tunnel shi Zuoce 11, side of the pilot tunnel temporary support 12.

Figure 4 in the shown schematic diagram of the digging open arches. arches in the excavation of the pilot tunnel 7, left and right side frame stand upright post 14, is laid at the bottom of the Provisional cross-brace 19, the initial supporting construction arches 15.

Figure 5 in the mould side wall of the second lining concrete schematic diagram. Construction left side hole the right side of the side wall of the hole the second lining concrete 17.

Figure 6 shown in the bottom of the excavation of pilot tunnel arches the side of the pilot tunnel schematic diagram. arches leave from the opening in the bottom of the excavation of pilot tunnel to the two sides of the arch portion of the pilot tunnel 8, constructing arches initial support structure of the two sides of the bottom of the guide hole 15 and the side of the pilot and the second lining concrete lining (that is, the secondary lining arches 20), treats arches side wall of the supporting structure and the supporting structure, the pilot sub-the left side of the 1, 2, 3 with the right pilot 4, 5, 6 of the cross 13.

Figure 7 is shown the opening side of the excavation of pilot tunnel arches 8 schematic diagram. In Figure 6 the construction is completed tunnel arches structure to an opening direction of the remaining arches side to continue to excavation of the pilot tunnel 8, segment removed in arches of the pilot tunnel 7 the two sides of the temporary support structure of H-shaped steel column 14 and the steel pipe at the bottom of the cross-brace 19, large-SPAN progressively completed arches structure of the tunnel excavation.

Fig. 8 shown the upper part of the schematic diagram of the core the soil excavation. The upper part of the excavation nuclear subsoil 9, remove the left pilot sections 1, 2, 3 with the right pilot 4, 5, 6 in the partition wall part of the temporary support 12.

Figure 9 is shown in the schematic diagram of the core at the lower part of the soil excavation. The lower part of the excavation nuclear subsoil 10, remove the left pilot sections 1, 2, 3 with the right pilot 4, 5, 6 in the partition wall part of the temporary support 12, the initial supporting arch construction 16, primary support structure of the tunnel is closed in a ring.

Figure 10 shown in the schematic diagram for tunnel excavation is completed. Construction invert to the secondary lining 18, tunnel secondary liner structure is closed in a ring, the complete tunnel excavation of long SPAN.

Figure 11 the design of this invention is shown digging three-dimensional schematic diagram of the jump arches , tunnel excavation cycle is a schematic diagram of the longitudinal section.

Figure 12 the design of this invention shown in the jump arches digging plane schematic, of the tunnel excavation cycle time is the cross section of a schematic diagram.

In order to reduce the large SPAN tunnel excavation from the earth's surface of the settling tank and increasing the range of the earth's surface, in the implementation of the design of this invention the following principles to be followed in : (1) two side pilot can not go hand in hand, the need to keep a certain longitudinal wrong distance , a single side of the three-step approach adit of excavation, holding at least one of every step 4m wrong distance of, in order to facilitate the face stability ; (2) three blocks arch portion of the excavation, arches first in excavating the pilot tunnel, then jump from the inside to the outside soil dug two sides ; (3) sealing as the side wall and the re-excavation archesnuclear subsoil after the second substrate, the final shi Zuoyang arch.