Considerable settlement took place while shifting the
posts, and eventually showed on the street surface and in the adjacent
sidewalk vaults, but no damage was done to the structural portions of
the buildings.
While the above work had been going on westward from Fifth Avenue, the
excavation of the Twin Tunnel eastward from the end of the open-cut
section at Sixth Avenue had been proceeding rapidly, and, toward the end
of the difficult Fifth Avenue work, it was being attacked from both
directions.
PROGRESS OF EXCAVATION.
Owing to the numerous sections of poor rock, interspersed throughout the
work with stretches of sound rock, the progress of the excavation was
very irregular, especially in 32d Street. The rate of excavation in good
ground is shown in Table 1. In the sections of bad ground, the
operations of excavation, timbering, and lining were often carried on
alternately, and it is impracticable to include them in the table.
TABLE 1.--PROGRESS AND METHODS OF EXCAVATION IN GOOD GROUND.
THIRTY-THIRD STREET.
============================================================
1 | 2 | 3 |
-----------------------------+--------+--------------------+
| | |
| | |
Type of excavation.
Pages:
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39