The evening times., 1899-01-03
SAFETY OF buildings
ADJOINING TUNNELS
Expressions of Opinion by EX-
pert London Engineers.
Proper Care Will Avert Danger to
Adjacent Houses.
Air Is Used SGains: InHcIrs
Of Water.

Paris. Jan 3-The Herald's European
edition publishes the following from its
ondon correspondent:
London is as keenly interested in the
subject Of danger to buildings from tun-
neliirg as Paris or New York, and moe
especially just now, as the question came
up in connection with the structure n
which the Bank Of England is housed, eX-
cayations being made for the new Cent al
London Railway through Threadneedle
Street, on the side Of the bank.
Ii was rumored that the walls of the
bank and the other buildings in the neigh
borhood had been weakened Though the
removal of earth, and cracks had even
been discovered in the bank building.
The officers OF the institution Immediately
called in Sir John Wolfe Barry, an emf
nent authority, TO make an examination
and suggest remedy. He said that the
matter was not serious, but the facu re-
mains that he is at work on plans Tor
strengthening the bank building.
Prof George Aitchison, who is president
OF the Royal Institute OF British Archi-
tects, professor of architecture at the
Royal Academy, and one of the most emf
nent men of his profession in England, Is
very frank in stating his belief that there
the vicinity OF underground railways or
tunnels He says:
Thc removal of the earth where The soil IS
clsy or gravel Is, Of course, had Tor the stabil-
iy of the buildings in the neelborhood, and
thiS Is especially The case where the eNcayated
spycc ! used for railway tunnel. The drawing
of of water from a claycy of sandy soil Is
bound To- result in an iniinn condition OF ground.
No matter how sUlidly the earth * packed down
around the tunnel; no matter how well built
flfn rFtII Tlp i 1sTl
Ins pf ot water ami The constant ltr1llng caused
by Jhe passing trains TIll gradually draw the
earth toward The vacant place and naturally the
result win he that the houses IN the ncigIbor-
hood viii sag toward the t:iurcl
The buildings III and around London are not
very tail. and I should think tlc danger would
lee much greater III a city Ike New York, Tor
instance. where IA" structures reach such great
heights and where the weight. Therefore, Is ~
iguUh greater; but let me roat, the experience
~ a friend oi mine living in The suburbs Of Lon
don. three-story house stands on clayey
SOL. and sorc ycars ago The railroad built Z
tunnel within a few hundred feet L. only
solae months when the laTTin- Of the passing
trans caused distinct CRACK IN the steps
through The sgCEUg OF the whole structure. and
shortly aiteTHard the garden wall. laid in bed
- concrete probably Two irct thick, showed a
tendency to lean toward The tunnel. too. and IL
pas absolutely necessary 10 rssiI and strengthen
it, There other danag" q" ;ic mouse. which
Ws~ strongly iluiit, that could %, attributed only
u IHc effects Of the jirIng t.al'.--
oi Cgarsc the damac. L. buildings adjacent
10 tunnels can be minimizcd and perhaps en-
Jirclv ayggIcd. ~ UndcTpnninE. hHl this Is an
expensive ard difficult undertaking. especially
where the houses are built before the railway
tunnel : de. To mdelliin a house after ii Is
iuilt costs a deal OF lnaEel and most persons
affected can III afford il.
Nhilo -c on ;hc sIlielt i the effect Cf
the drawing on Il water from oJvey SOL let me
Jrll sou little incident IN London history. la
-. luHU's Wood. just after that section Of Ion
don first developed. perhaps ffy wears ago there
uI~ great drought and The earth cracked
MaI- lugScs. which IL j. true were not very
strongly built. were damage q thar they had to
lac torn down. and that tine case where there
MAS no jalIug Trains TO increase the trouble.
Aeo ] am firmly OF the opinion thar railway
tunnels seriously affect tar safety IF buildings.
I ~ roaiiv impossible to .#E whore the greatest
danger lies IN London. for tl.erc J. soil OF all
SORTS. but the general statement Eay bc made
ihai 'aycy aud sandy soils age most easily
affected.
Professor Aitchison said that generally
speaking the buildings in London were
sound in construction. Buj as ia all great
cities there were all kinds of work. and
probably in the poor and outlying sections
there were structures OF fiimsy charac-
Ter
Mr.. ]. B. Squire, of the prominent firm
of civil engineers. s. Pearson & Son, Who
carried through. about fifteen years ago,
the inner circle of The London Metropoli-
tan and District Railway, TALKING on the
matter, said:
II was the most dangerous and difficult piece
81 underground tuuncluG carried out. yet we
bad no subsidences or any trouble OF that sort
Ne had TO cut underneath lie heaviest houses.
and did 50 Without Wont say danCeG-but
without nshap. The reason %: this simply
the exercising Of a proper amount OF .are.
Two great requisites Tor tWneiing care
10 t.7pg.g,r1 gu
piuuing.
ono of our difHeultg's vas King William :
statue. composed of $50 tons of granite, and it
stands right on top of tie underground rail-
wsy. There never was and G'vrr has been any
danger oi subsistence there al these fifteen years.
The secret is simply perfect UndeIpinnng-
E. ". Moir. Of the same firm. who car
ritd through the Blackwell tunnel, and is
also engaged on the Hudson River tunnel,
said:
IN underground tunnciug measures must be
taken TO meet the cxigeuric- Of every case For
instance. where there i danger oi Suhsidcnce
from inflow of sand and water, il can be
stopped hg means OF working with compressed
ain against the face where the material is flow
ing iH: THAT is te say. the air pressure being a
greater force than water. the water not only
t.aa~sS How. but viii be driven back. and the
sand would bc as easily cN,&vatcd dry sugar.
SuppoSing. again. We had 4 suI>idcncc Il the
houses over 0ur tunnel. and that We found there
distortion Nl Inc hrltk iilllii-- nat could
best hC rectitied by sIh,idizing The iron. and
thoroughly grouting mp the space between the
''Noavated hollow and the lining with a semi
nuid cement lime.
That also should be put in undcr pressure,
lui ii a tunnel is driven on the shield system,
as j. now carried ont in all the deep tunnels
under the city Of London there is no earthly
reason why there should be any subsistence at
all. OF course. the shield alone would not pre-
went a settlement under running sand, but the
Shield combined with air pressure could not fail.
Take example The blackwell tunnel. That
viii illustrate what ] mean. With combna-
tCn patent shield and compressed air act
uallN cut within FIVE feet OF The bed Of the
Thames through sand and slingIe Also in the
Hudson tunnel went the way through
mud as soft road scTapines within twenty
three feet Of the bed Of the river. and with a
pressure of fifty feet Of water above MS.
Mr. Thomas Meik civil engineer agreed
with MIR. Moir as 10 the causes of subs;-
dences, and also that with due precaution
there need never be any danger TO houses
or buildings in the vicinity
Even, he said, IF the tunnel were cut
through sand of moist material there
should be no danger Under the old sys-
TEN of building tunnels there WAS consid-
cradle risk of houses cracking or even fall
ing in, but under the modern method of
iron tubes, as in our Central London rail
way, we can cut under any building with
perfect safety. If anything goes wrong L
must surely be owing 10 some want OF care
in construction"
Defends Himself With an Ak.
Richmond. Va, Jan. 3.-Thc faculty Of Rich.
mund College yesterday evening had under in
vestigation hazinE which took place at that
institution during the Christmas holidays but
which jnst leaked ont.
The victim was Mr.. c. y Smith He defended
himself against thr would-he hazers so vigor-
ously with an AK that the crowd was forced to
leave him