xt7b8g8fj607 https://exploreuk.uky.edu/dips/xt7b8g8fj607/data/mets.xml United States Housing Authority 1939 20, [5] leaves: ill., plans; 27 cm. UK holds archival copy for ASERL Collaborative Federal Depository Library Program libraries and the Federal Information Preservation Network. Call Number FW 3.9:25 bulletins English Washington, D.C.: Federal Works Agency, United States Housing Authority Contact the Special Collections Research Center for information regarding rights and use of this collection. Works Progress Administration Housing Publications Soil mechanics -- United States Public housing -- United States Sub-surface Soil Investigation: Technical Material for Information of Architects and Engineers/Federal Works Agency, United States Housing Authority August 1, 1939 text Sub-surface Soil Investigation: Technical Material for Information of Architects and Engineers/Federal Works Agency, United States Housing Authority August 1, 1939 1939 2019 true xt7b8g8fj607 section xt7b8g8fj607 I Q‘K7 :2 a > \.
37‘3“}: ,4 . ._
i
ANIIMIWNHIA‘IAWAHNAmAA
3 EILIES H‘lB‘lDBLI a
' FEDERAL WORKS AGENCY
UNITED STATES HOUSING AUTHORITY
Bulletin NO. 25 on Policy and Procedure
W.
- 3%; WETORY
i
‘ m UBRARlﬁs
1!
SUB—SURFACE SOIL INVESTIGATION
Technical Material for Information of
Architects and Engineers
(August 1, 1939)

i
i 71372 H
I .
g Eéﬁﬁ
} INTRODUCTION 1
[ PABT I: d PROCEDURES IN ARRANGING FOR INVESTIGATIONS 3
{ PART IIi DETERMINATION OF EXTENT OF INVESTIGATIONS 5
‘ A. Preliminary Investigation Prior to
t Loan Contract 5

3. Comprehensive Investigation SubseQuent '
j to Loan Contract 5
3 PART III: TYPES OF EXPLORATION 8
A. Open Pits 8
i
g B. Borings ' 8

C. ’ROd Soundings 9
E D. .Observing Ground Water LeUels 9

PART IV: RECORDING AND ANALYSIS OF DATA. A 10 _

3- A. Field Records and Samples 10
1
l B. Preparation of Log “ 10
i G. Analysis Of Data 10
D. Allowable Load 14.
3 PART V: LOAD TESTS . - l7 '
i . PART VI: APPLICATION OF DATA TO FOUNDATION DESIGN 19 -
I .
g .

' ' ' were Hi
The suggestions in this Bulletin. however. in"no way,
relieve the housing project designer of the responsibility for ,
; relating" these recommendations to lecal building code .muire~
: ments, local practices;- and local geological conditions. Theft ‘
this be done is, in fact, the most important-recommendatioan
the Bulletin. ' ' ' ‘ .
': Because project conditionerdifi‘er so widely no hard and
fast rules for benduc'ting thorough Sub-surface“ investigations ‘
may be -~ listed. The general suggestiops which iollow’ are offered
, - as constructive aidin'udevel'oping themecessaéy‘procedure for a
thorough study of these- conditions. ~‘
2

71372 H
PART 1
, PROCEDURES lg ARRANGING EQR £§E§§TIGATIONS _

1. It is the responsibility of the local housing author~
ity to determine the extent of, and to make arrangements for,
the necessary sub—surface soil investigations.

2. Where it is evident that only a limited amount of
investigation is necessary, the local authority may request
its architect to arrange for and supervise the work, or it .
may engage an engineer and hire the labor to make the in;
vestigation on force account as part of its administrative
expenses. Such work should be limited to costs 223 exceeding
g§§_thousand dgllars, unless limited to a smaller cost by
local law.

8. Where investigations involve costs which probably
will exceed one thousand dollars, or a lesser amount in com—
pliance with local law, it is advisable to prepare Specifica—
tions for the work to be done and request bids from contrac-
tors experienced in this class of work. The work should
be awarded to the competent and qualified contractor submit—

' ting the lowest bid. The services of a competent supervising
engineer may be included with the specified work or may be

' arranged for as a separate contract. The architect’s en—
gineer who is to design the foundations should either superm
vise the soil investigation or should collaborate with the
engineer engaged to supervise the work. Copies of all
Specifications, invitations to bidders and bids for contract
work, together with the recommendations of the local author—
ity for award of contract, and c0pies of the prOposed con—
tract agreements, should be submitted to the United States
Housing Authority for approval before making an award.

4. All work, either under force account or under con~
tract, must be done according to the provisions in the "Terms
and Conditions” of the Loan Contract. Of these provisions,
the following should be incorporated in any specification
prepared:

hours 9: Work.

ﬂags Rates.

Ray Rolls, Project Data apd Records.

Eigk~Back §tatute apd Regulations.

5. Where work is to be executed by contract, unit prices
shall be requested with the bids for additions to, or deduc—
tions from, the work Specified. These are usually requested

71372 K

per lineal foot for each type of boring. Because the
relative cost increases with increase in depth, different
unit prices are adyisable for open pits, for each succeeding
five feet in depth, or some similar increment in depth.
This may be determined by the probable necessity for sheeting
below certain depths. It is recommended that a minimum amount
of work for each type of exploration, usually expressed as a
total lineal footage. be guaranteed to the Contractor. The
estimated maximum cost, which will not be exceeded without
further approval of the United States Housing Authority, .
should accompany the local housing authority’s recommenda~ ‘
tions for award of a contract.

71372 H
PART I; .
DETERMINATION CE EXTENT CE INVESTIGATION
A. Preliminary Investigation Prior 39 Loan Contract:

1. A preliminary investigation is essential prior
to making application for a loan contract and prior to
Optioning or acquiring a site, to determine that the pro-
posed site will not involve excessive foundation costs,
and to justify the preliminary cost estimates which accom-
pany the application. Comparatively favorable sub—surface
conditions may often be the decisive factor in the choice
of a site. In some instances. tentative sites may be
abandoned because investigation reveals unfavorable sub—
surface conditions.

2. Much pertinent data for preliminary investiga—
tion is obtainable locally without making ground explora—
tions. Local city records and topographical maps are
usually accessible. These will indicate probable under—
lying formations and the geological history of the area.
Old records often show whether at some prior date the site
included a ravine, swamp, pond or gully, which has sub-
sequently been filled in or covered by alluvial deposits;
whether it has been used as a dump; or whether surface
conditions have changed in some manner. Geological history
will indicate the probable presence of glacial deposits.
Old residents in the neighborhood, excavating contractors,
and utility companies may be questioned as to their know—
ledge of the underground conditions and Surface changes.
Neighboring buildings, as well as those on the site, should
be closely inepected for evidences of damage resulting from
unequal or excessive settlements, the types of foundations
used, and the dry or wet condition of basement or cellar
Spaces. All such available data should be carefully and »
thoroughly collected and recorded. These records should
be analyzed to determine if some soil exploration on the -
site is advisable prior to making the application for the
loan, or acquisition of the site.

B. Comprehensive Investigation Subseguent 39 Loan Contract:

1. After a loan contract has been consummated and
prior to actual foundation design, a comprehensive in—
vestigation should be made. The extent of such investiga—
tion depends on many factors, and should be determined by
the architect‘s structural engineer. Who will use the
data for his design. .

71872 H
2. The soil stratification. at a given location.
may be determined in a number of ways. The oldest, and
best method is actual excavation of pits, by which the
stratification is exposed for examination, and.conditions
which will be met in actual foundation construction are
seen in their true relations. Where great depths or
frequent exploration are needed, or where ground water is
‘ encountered, borings will probably have to be made. Rod
soundings occasiOnally are used to advantage. '

' 3- (a) Each site is.an individual problem, and the
preposed number, location, and depth of Open pits or borings
must be determined from the preliminary_data that have been
obtained. These may need to be augmented as the exploration.
proceeds and discloses the necessity for additional informa—
tion. ' '

i
(b) On sites where the preliminary data indicate
that favorable bearing soils lie close to the surface, it
may prove sufficient to excavate only a few Open pits to
verify theiassumed data. Where the preliminary data or '
the open pits indicate the presence of top fills or soft
grounds, or the presence of questionable underlying strata
is indicated or suSpected, it is advisable to make a .
number of borings. These may be few in number, located
in well distributed, representative areas of the site. if
the sub—surface strata are found to be definitely uniform
in character and level. On the other hand, if the evidence
indicates varying fills or underlying strata, pockets of ‘
unfavorable character, or wide and rapid changes in strati-
, fication. a sufficient number of intermediate borings should
be taken to determine the extent and VariatiOn of such areas.
On many sites. borings should be made under each corner of
the preposed buildings. and in some instances between corners.
(c) The necesSary depths of the borings will be
governed by the underlying conditions, but they should ex~
.tend sufficiently to assure at least four feet of uniform
bearing stratum under the footings. Where soft underlying
strata are indicated or suSpected, a few of the boringsv
_should extend to depths 15 feet below the footings. Borings
may well be supplemented by a few pits, which are invaluable
. fer gaining complete understanding of the foundation diffi~
culties in unknowu sub—surface conditions. Under certain
conditions—~fcr example, to determine the approximate contour
' of a rock stratum within depths of preposed bearing, or the
. depth of soft ground——sounding bars may be used to augment
. data disclosed by the pits or borings. The use of sounding
bars may be misleading for it is not possible to determine
accurately the nature of the material penetrated. by making
6

. .

71372 H
several soundings within a radius of a few feet. however
these instrumonms will check the presence of a boulder.

4. Where the suitability of a soil for bearing is
dDUbtful. load tests should be made to determine the safe ,
allowable load. Where the necessity for pile or caisson
foundations is indicated. load tests are usually specified

' to be placed on selected piles. after some of the piles in
the contract corstruction work are installed. in order to
verify the assumed driving resistance end bearing values. _
It is not practical to place equipment on the site to drive
a few test pile: in adVanco of awarding contract work.

.5. It is «ssential to make accurate observation of
ground water leiels, and.to supplement such observation
with information obtained from lOCal sources regarding
Variations in 1 vols. This is particularly advisable Where
footings are to rest in clay, or other relatively imperm
meable strata which will hold water against the foundation
walls and the underside of the basement floors. so that . -

- necessary drainage and water proofing may be provided in
construction of the proposed buildings.
I7

GIG/437'!
fuzz- P/LE AND 534::
Azowwa 544/413 0e DEEP 54m: 7'0 gag-p P/7' oer
Pms. Pea was OPA'N/A/Gs ode/N6 £XPLO£4770M
/,v PIA/N6 Foe caste mar/av ,
63‘0“: ﬂ
» . W .
l I “‘4! ’75
"‘1”:
l I v, 4711"
| l ‘ '-"
I i ”
II I _ n
‘H.
'1 ."
ﬂ—J “‘ ! gull": “_I?I
Pea/90.540 All/42. a; , m5 ‘
5077-054 0F fwﬂA/GS g 3%
oz 1.0ng m 6000 g '
daze/N6 50/4.
‘Q x/AA/o 40am #024:
Q 0e doe/N6
TKO/CAL Ops/v P/r Exp; 024 770A/
Ill/3166' 9

71372 H
PART III
TYPES OE EXPLORATION
A. Open Pits:

1. Open pit excavations are illustrated in Chart I.-
Micro such pits exceed 8 feet in depth, or lesser depths,
in some kinds of soil, the walls of the pits often must
be braced. Care must be used 13 arranging bracins pg
permit observatign of the undisturbed materials.

2.‘ The pits should extend to levels at which it is
proposed to place the bottom of the footings. If an un—
satisfactory bearing stratum is found at such depths, the
pits should be extended, within reason, to satisfactory
bearing strata, which are suitable for the proposed type
of footings. é minimum four foot thickness of bearing
strata should pg verified by making a boring into the
soil at the bottom of the pit.

3. The material from the pit should be piled as re~
moved, and sufficiently scattered to allow thorough exam—
ination. The relative amounts of the various kinds of
materials may be more clearly determined in this way than
from the exposed sides of the pit, but the hardness and
moisture content of the various strata will not be so
evident. Arrangements should be made to backfill the ex:
cavations as soon as the pit and the excavated materials
have been examined and recorded. ‘

B. Borings:

l. The essential fnnctiqn Q: a boring is 39 obtain
authentic samples and true elevations 9f the various kinds
9: soil, including various soft materials, and £2 permit
determination 9: true ground EEESE levels. This can onlx
be done reliably b1 the use 93 dry core boring eguipment.

2. Drv core borings utilize a driven casing pipe.
Through this a smaller size pipe is driven after the
earth Within the casing pipe is cleaned out by one of seve
eral methods. The smaller pipe is fitted with a valved -
bottom, which progressively penetrates the undisturbed
stratum below the bottom of the casing pipe as the explora—
tion proceeds to the various depths, and a core 93 slug

9: the soil ip its natural s§a£e_i§ collected.

3. wash borings are often utilized for both deep and

‘ shallow explorations. Except as a method of cleaning out
8

71372 H
the casing pipe for dry core borings, this type of boring
is not recommended because samples of the material pane»
trated cannot be examined in their undisturbed condition.
The water used for cleaning out casing pipes makes it im—
possible to determine moisture content, or to lOCate ac—
curately ground Water levels.

4. Angers are also extensively used for borings.
-~ Their satisfactory use is limited to materials which will
stay in the helix of the auger until brought to the sur—

' face——for example, dry earth, clays, and combinations in
which sufficient clay is present to make the material co~
hesive. It is especially difficult to make theSe borings
in any soil other than clay if water is present, as the
water carrying the soil from the surrounding strata will
flow into the bore hole. Auger outfits utilizing derrick
and hoist have been used for cleaning out the casing pipes
'for dry core borings. When sand is encountered it often
becomes necessary to use a sand pump or water jet. It is
usually advisable to start a new hole, when boulders are
encountered, although they are sometimes broken up with a
chopping bit. Angers are especially adapted to verifying

‘ the depth of satisfactory clay, or clay and sand strata at
the bottom of open pits. They may also be used for such
verification, after excavation for footings, during con—
tract construction work.

C. Egg Soundings: '
l. Sounding is usually done with bars 5/8 inch to ‘
. 7/8 inch in diameter, depending on the material to be
penetrated. The bottom length usually is pointed and
10 to 12 feet long, to permit it to be churned down 6
to 8 feet by hand. Additional lengths are coupled on
and driven with a 10 to 12 pound maul.

8. Samples have been Withdrawn by using a short
piece of gas pipe on the bottom of the red, but such ,
samples are necessarily difficult to obtain and are not
reliable. _

D. Observing Ground Water Levels: *

1. Certain representative bore holes should be se~
lasted for observation. Eng observations should ggtend _
over 2 period 9: at least one week to allow Eng water to '
come to eguilibrium EE its natural level. To permit this,
the hole must be covered and protected to prevent surface

g water from running directly into it. .

MP/ N92 M93 NI 4 M25 M25 (3
ace/M5 doe/M; Jae/#6 opaw P/r dﬁe/MG cog/M5 1%
h
g.
m /'
r/a , r/“o ' E ﬁ// ""’n----
m 7" . , 91% Mar/ 1 = 4576...... M”/
j4j_"§/Z 5/ E 237 m a / 4 "é‘ 5w /" y (”W/4 E 5/ng
. E C ex: = , a 1= m ‘ ' .-
V ’” 40— 0M” ’ ‘2 ’47}; spy / 552;? 5}? Jam/V
% 59w V Jam/y 4-16 := 6mm a”? / Clay
Clay / 574 {7/ .Sil/v’y 59009 / Wef-
/ 5076‘ f of; / 60/3; f (by maf /
% 1/4204 M4/5 fwe" //,4m,%,.;;g #5.!“ a,
//.0 4 land . 4 #7! /g, r m J'ana’ V 14m 2/):
. 1m f7”! V ‘ ”9/7! / \ (.76 V
V 6/: \ \\ ”"0 A5 \ Ye/Zw \ (/ch
\ Ve/Za/w \ \ C/JV V Max \ Yeﬂow
\ m \ 54%” § W \ § W \ :36?
" \ Med \\ t \66y 5'0 75\ é
— . Z5 5 My" 7 c7 K
’Wdﬂﬂﬂr Wer‘ y, C/ay \ﬁgw I £52);
676' 45/0: 51/1
. / [ff/c; ﬂax—d \
4.0 A 6:. I I k\ . ’
ya
30 ﬁg}! ‘560/ C24)’ JIAOW féfl/Af/O/J "//5 AS A £42477V£ZY WPA'iMIAaLE CZAY of
3-15 Graye/ Mia/m4 cox/55mm Hal/a4 /5 cams/942:0 7‘0 ”,4 v: 4 32/2- Azzamaa- ﬂea-Jae:
[0 755;, 0; A5 rams Fae same: #0077
*9“ 72/: .‘MA/DY CMY 450V: 774/5 1.51/54 /.5 502-7,- jaauA-‘cr 7-0 5£WG
”" ewe 44.7272/144722)’ Mir 4ND Dex 4M0 A0074 5/ “Mae‘s-55454:.
5 .
§
9
Q 7360/64; 4 06 0F OPE/V ,0/7'5 4N0 502/A/GS
\

71372 H
PART 1.}:
3120.012qu an suites a: as».
A. Field Records gig Samples: -

l. Careful field records should be kept of all
matters and conditions pertinent to the work. These
notes should include the elevation of the surface at
each pit orvboring, the depth at which each stratum is
encountered, the kind of mat erial in each stratum,
whether the mat erial is hard or, soft, whether the ma?-
terinl will stand without casing or sheeting, the loca—Q
tion and nature of obstructions encountered, and other
items that may assist in the interpretation of the earth
stratification. . -

2-. denies 22—: are. easih more he Maine. 9:: leach
Wchame 9.1: at 2‘. album... in :1: sash .5 she: is damn 9.1: ”each
stratum. As they are taken and before they dry out,
samples should be placed‘in wide mouthed bottles, tightly
corked or Capped to preserve the original moisture in the
material. Gummed labels, on which are printed the locar'o .
tion of the boring and the depth or elevation of the g
stratum. should be. placed on' each bottle for i.dentifica'—_
tion. @333; preoaptipp should log Egg to make the ,
samples truly representative 93 the material encountered.

B. ‘Prewationgf 14%:

l. A drawing showing a gomnlete log 9: the e'gplora-i-
tion data. gs illustrated in ghart ll. together with a
site plan showing the dimensional location of all pits, '
borings and soundings , should be parefullv prepared. 21353
lgg should be comprehensivg, showing the kind of soil in.
each stratum, the ground Water levels, the surface slave-'-
tion of the ground and the depth to. or the elevation of.
each stratum. Each kind of soil should be adequately ,
described to show whether it is hard or soft. its Incisi-
ture content, and its relative permeability or capacity ,

.to drain free of water. The Various soils and their con-'-
dition should be indicated by symbols and descriptions,
_ as, illustrated in Chart 2);. ‘
0- nan as. .9: sea: ,

1- no new and if. ile are .rf.a.c..e. .i.n.v..e.s.t...1.+
gation ip; to egtablish the type. 3: foundation which will
result _i_._1_1 uniform settlement within msonable limits. -

p as every soil except rock is compressible. Measurements
10

71372 H
of settlements have shown that absolute equal settlements
rarely occur even under like unit loads on many of the
common soils.. This is evidenced by the frequent appear-
ance of settlement cracks in the masonry walls of exist-
ing buildings. In most instances. such cracks have ‘
made their appearance years after construction, demoné
strating that uneqpal settlements increased with time.

In other instances, cracks have appeared at an early
date. and no further cracking has developed. This in—
dicates that non-uniform settlement occurred immediately
after the load was applied on the soil. and then ceased
almost entirely as-the Soil became consolidated, with
further settlement small and uniform, if at all. gbser—
vations further indicate that ends of buildings placed
close to adjacent buildings often settle more than ends
which are further apart: that center portions of~long
walls settle more than the corners of the buildings. or
the shorter end walls; that interior foundations settle ,
more than exterior walls, and. generally; that settle—
ment is greater near the center of long buildings than ‘
near the ends. Some soils near the surface expand and
swell when saturated. and shrink and crack open when dry.
actually raising and lowering, alternately, entire buildk
ings. In a few instances. portions of a building have
heaved upward_while other portions settled. Buildings
which settle uniformly often settle more than the adja~
cent Surfaces, causing_objectionable. and. at times,
unsafe relations between floor level and adjacent en~
trance stoops. porches. or walks, and causing damage to
underground utilities extending from the buildings., These
evidences indicate the need ﬁg; a thorough and egperienced
83.812818.

2. Settlement under load is essentially of-two difé
ferent types:

(a) Settlement due mostly to lateral flow of the

underlying strata, with little or no consolidation.

Characteristic of this type is the fact that the

Volume of settlement is practically equal to the '

volume of soil which flows laterally from undere

neath the building. If due to low permeability

of the soil. the consolidation attributed to in;

creased pressures proceeds slowly. The volume

displaced by lateral flow represents practically

the entire vertical displacement which the buildu

ing will undergo. at-least for a period of many.

years. If the lateral flow is arrested by driving

sheet piling or by'similar.methods. the settleé \

ment will practically stop.

(SH/127' E
azasrenrwg 08055 55C7/0A/A4. .57'1/0/53 Foe
AIS/V06 MAL 51/5- SUeFACE COND/T/OA/6
X
.. /7 /-‘.. ../‘7 ./ .. Z
---—III----*----
.mnmzﬁ! IEIIl-m 12mm",
on OﬂI/V Pm: osﬁae/A/as k-AﬂﬂlﬂaA/AL doe/mas ---- .Peamsw F7454!“
” 5/ 7‘5 PLAN
i . xo / _ 4 /z 5 / . M. 5 AF
_£§§§§§A #74. ﬂagga
:~~‘ ‘— V\\\‘ ‘\ iv»: _——-.——"""' a ,.—.
gmmmmm»