JPH0791957B2 - Construction method of separated pillars in shield tunnel with composite section - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention relates to a composite cross section shield tunnel in which struts to be installed between the left and right rings are constructed at intervals so as to maintain a sufficient space therebetween. , The construction method for constructing underground stations and switching intersections of subway lines.

"Problems to be solved by conventional techniques and inventions" Recently, a shield construction method is being developed to integrally construct a compound cross-section tunnel in which circular rings are superposed in two or three rows on the left and right to form a double circle. However, in this method, since the middle pillar is assembled for each front and rear ring between the upper and lower pillar joints in the segment between the left and right rings, sufficient space is maintained between the front and rear middle pillars. However, when constructing underground stations or switching intersections of subway lines, there was a problem that densely arranged center pillars hinder that.

[Means for Solving Problems] In order to solve the above-mentioned conventional problems, the present invention is a sheath in which a plurality of rings in the direction of excavation are communicated in series as a set to a column connecting portion in a segment between left and right rings. In this set of rings, assemble the main strut between the upper and lower strut joints of the rings located at the front and rear ends and the temporary strut between the upper and lower strut joints of the ring located in the middle. , The pillar joint between each pair of rings by removing the temporary pillar after introducing prestress by the PC steel material inserted into the sheath that communicates with each pillar joint of the pair of rings and integrating The composite beams that are integrated with each other are made to act, and the axial force, which was taken up by the removed intermediate temporary support pillar, is applied to the main support pillar through this beam, thereby maintaining a sufficient space between the main support pillars. Or Tanks in which like proposes a spaced struts construction method in a composite section shield tunnel as may construct such switching 換交 difference path passable underground stations or subway road with a margin.

"Example" Hereinafter, an example of the present invention shown in the drawings will be described.
A composite tunnel shield excavator equipped with a compound circle excavator 1 is used to assemble segments in the rearward direction while constructing a shield tunnel with a compound cross section in which a plurality of segment rings 2 overlap left and right, and between each ring 2 and 2. Is a box-shaped block-shaped strut joint 3 assembled segment, and the main strut 4 or temporary strut 5 is assembled and supported between the upper and lower strut joints 3 and 3 for each ring that is assembled back and forth by bolting or the like. (FIG. 2 (a)).

A plurality of rings 2, 2 ... that are assembled in the front-back direction are formed on the column joints 3 formed in the segment between the left and right rings 2, 2.
A set of (5 rings in the illustrated embodiment) is set as a set, and a sheath 6 communicating in series with them is embedded in advance.

Then, the main strut 4 is provided between the upper and lower strut joints 3, 3 of the ring 2 positioned at the front and rear ends of the pair of rings 2, and the upper and lower strut joints 3 of the ring 2 positioned at the middle portion. Assemble the temporary support column 5 between 3 and 3.

Next, a prestress is introduced by the PC steel material 7 into the sheath 6 forming a series between the strut joints 3 of each pair of rings 2 to integrate the strut joints 3 (Fig. 2 (b), third). Figure),
After constructing a composite beam in which these are connected and integrated, the intermediate temporary support column 5 is removed, and the axial force that they have taken on is applied to the main support column 4 via this composite beam, whereby the main support column 4 A sufficient space is maintained in 4 and 4 (Fig. 2 (c)).

The above steps are sequentially and continuously applied to a new set of rings 2 including the tip portion of the preceding main strut 4, and the temporary strut 5 removed in the preceding step is sequentially diverted.

As a result, it becomes possible to construct an underground station or a switching intersection of subway lines that allows people and vehicles to pass between the main columns 4 and 4 with a margin.

[Advantages of the Invention] As described above, according to the present invention, a sheath that communicates in series with a plurality of rings in the excavation direction as a set is embedded in advance at the column joints in the segment between the left and right rings. Assemble the main strut between the upper and lower strut joints of the rings located at the front and rear ends of the ring, and the temporary strut between the upper and lower strut joints of the ring located at the middle part,
Since the pre-stress is introduced and integrated by the PC steel material inserted into the sheath that communicates with each strut joint of one set of rings, the temporary strut is removed, so the strut joints between each pair of rings are integrated. A beam that has been converted into a structure is made to act, and the axial force that was taken up by the removed temporary support pillar is applied to the main support pillar via this beam, thereby maintaining a sufficient space between the main support pillars, people, vehicles, etc. It will be possible to build underground stations and subway switching crossings that allow passengers to pass with plenty of time.

[Brief description of drawings]

FIG. 1 is a perspective view of a composite cross section shield tunnel constructed according to the present invention, FIGS. 2 (a), (b), and (c) are vertical side views showing the steps of the present invention, and FIG. 3 is a post in the present invention. It is a cross-sectional view showing the prestress introduction state of the joint. 1 ... Composite cross section shield machine, 2 ... Segment ring,
3 ... prop joints, 4 ... permanent props, 5 ... temporary props, 6 ... sheath, 7 ... PC steel.

Claims (1)

[Claims] 1. A ring which is preliminarily embedded at a front and rear end of the pair of rings by previously burying a sheath which is connected in series with a plurality of rings in the direction of excavation as a set in advance at a column joint between segments of the left and right rings. Assemble a permanent strut between the upper and lower strut joints of the above, and a temporary strut between the upper and lower strut joints of the ring located in the middle, and insert it into the sheath communicating with each strut joint of the pair of rings. A method of constructing a separated pillar in a composite section shield tunnel, characterized in that the temporary pillar is removed after introducing prestress by the PC steel material and integrated.