home study 05 15 06study committee that included both geology and geotechnical experts. the...

AN EVALUATION OF THE GEOTECHNICAL ENGINEERING AND LIMITED ENVIRONMENTAL ASSESSMENT OF THE BEVERLY HILLS DEVELOPMENT, NEW HAVEN, CONNECTICUT

MAY, 2006

A REPORT BY

THE CONNECTICUT ACADEMY OF SCIENCE

AND ENGINEERING

FOR

THE CONNECTICUT GENERAL ASSEMBLY

AN EVALUATION OF THE GEOTECHNICAL ENGINEERING

AND LIMITED ENVIRONMENTAL ASSESSMENT OF THE

BEVERLY HILLS DEVELOPMENT, NEW HAVEN, CONNECTICUT

A REPORT BY

THE CONNECTICUT ACADEMY OF SCIENCE AND ENGINEERING

ORIGIN OF INQUIRY: CONNECTICUT GENERAL ASSEMBLY

DATE INQUIRY ESTABLISHED: MARCH 1, 2006 DATE RESPONSE RELEASED: MAY 15, 2006

© Copyright, 2006. Connecticut Academy of Science and Engineering, Inc. All rights reserved

CONNECTICUT ACADEMY OF SCIENCE AND ENGINEERINGii


This limited-scope study was initiated at the request of the Connecticut General Assembly on March 1, 2006. The project was conducted by an Academy Study Committee with the support of David Pines, PhD, Study Manager. The content of this report lies within the province of the Academy’s Environment Technical Board. The report has been reviewed by Academy Member Gale F. Hoffnagle. Martha Sherman, the Academy’s Managing Editor, edited the report. The report is hereby released with the consent of the Study Committee.

Richard H. Strauss Executive Director

CONNECTICUT ACADEMY OF SCIENCE AND ENGINEERING iii


MEMBERS OF THE CONNECTICUT ACADEMY OF SCIENCE AND ENGINEERING

STUDY COMMITTEE ON AN EVALUATION OF THE GEOTECHNICAL ENGINEERING AND

LIMITED ENVIRONMENTAL ASSESSMENT OF THE BEVERLY HILLS DEVELOPMENT, NEW HAVEN, CONNECTICUT

R. Laurence Davis, PhDProfessor, Earth and Environmental Sciences

University of New Haven

Kimberly ClarkeSenior Project Manager; and

Gail Batchelder, PhDTechnical Director, Hydrogeology

Loureiro Engineering Associates, Inc.

Kenneth R. Demars, PhDAssociate Professor of Civil and Environmental Engineering, University of Connecticut

David Freed

Associate, GNCB

Mohammad Saleh Keshawarz, PhDAssociate Professor of Civil Engineering

College of Engineering, Technology, and Architecture, University of Hartford

Ralph S. Lewis (Academy Member), ChairmanAssociate Professor in Residence of Marine Sciences, University of Connecticut

State Geologist, Connecticut Department of Environmental Protection (ret.)

Richard P. Long, PhDEmeritus Professor of Civil and Environmental Engineering, University of Connecticut

Brian J. Skinner, PhD (Academy Member)Eugene Higgins Professor of Geology and Geophysics, Yale University

SUPPORT TEAM

Study Manager Academy Project Staff

David Pines, PhD Richard H. StraussAssociate Professor and Chair Executive Director Department of Civil, Environmental, and Biomedical Engineering Connecticut Academy ofCollege of Engineering, Technology, and Architecture Science and EngineeringUniversity of Hartford

CONNECTICUT ACADEMY OF SCIENCE AND ENGINEERINGiv


CONNECTICUT ACADEMY OF SCIENCE AND ENGINEERING v


TABLE OF CONTENTS

I. INTRODUCTION ............................................................................................ 1

II. FINDINGS AND SUGGESTIONS FOR FURTHER STUDY ..................... 3

APPENDIXES ....................................................................................................... 6

Appendix A: Figure 1: Subsurface Exploration Plan and Organic Stratum Isopleths ............................................................ 6

Appendix B: House Survey ....................................................................... 8

Appendix C: Report of Foundation and Structural Assessment .......... 9

CONNECTICUT ACADEMY OF SCIENCE AND ENGINEERINGvi


INTRODUCTION

CONNECTICUT ACADEMY OF SCIENCE AND ENGINEERING 1

AN EVALUATION OF THE GEOTECHNICAL ENGINEERING AND LIMITED ENVIRONMENTAL ASSESSMENT OF THE BEVERLY HILLS DEVELOPMENT, NEW HAVEN, CONNECTICUT INTRODUCTION

I. INTRODUCTION

Many homeowners in the Beverly Hills residential subdivision in the Westville section of New Haven, Connecticut, have reported, through two neighborhood surveys, that their homes have experienced settling that has resulted in damage to building foundations and structures. It has been reported that the homes in this subdivision were constructed on the site where an ice pond was filled in during the late 1930s. On behalf of the City of New Haven, HTE Northeast, Inc., performed a “Geotechnical Engineering and Limited Environmental Assessment” (the “HTE Report”), dated May 27, 2005, to determine the foundation-related and environmental factors affecting these homes. As stated in the HTE Report, the objectives of this assessment were to: “perform limited subsurface explorations within designated public roadways throughout a portion of the residential subdivision in order to assess the probable cause(s) of structure settlement and to develop conceptual geotechnical engineering recommendations for underpinning of distresses to residential foundations, and to preliminarily assess the environmental quality of in-place fill soils.” Additionally, it was noted that the scope of work performed by HTE Northeast, Inc., did not include explorations of private residential properties in the subject area, and it was suggested that site-specific investigations of these properties should be undertaken prior to taking remedial actions to correct any identified structural issues.

The Connecticut Academy of Science and Engineering was asked by the Connecticut General Assembly to conduct an evaluation of the HTE Report to provide an independent assessment of its accuracy and completeness and to verify its findings. This was accomplished by convening a study committee that included both geology and geotechnical experts. The committee’s findings are based on a review of the HTE Report, a discussion with New Haven’s city engineer, and deliberations by the committee.

CONNECTICUT ACADEMY OF SCIENCE AND ENGINEERING2


FINDINGS AND SUGGESTIONS FOR FURTHER STUDY


AN EVALUATION OF THE GEOTECHNICAL ENGINEERING AND LIMITED ENVIRONMENTAL ASSESSMENT OF THE BEVERLY HILLS DEVELOPMENT, NEW HAVEN, CONNECTICUT FINDINGS AND SUGGESTIONS FOR FURTHER STUDY

II. FINDINGS AND SUGGESTIONS FOR FURTHER STUDY

The probable cause(s) of reported structural damage cannot be determined from the information provided to the committee. The HTE Report is useful but not sufficiently conclusive to allow the committee to determine the cause(s) of any suspected structural damage to homes. It is suggested that additional investigations are needed to determine the accuracy, type, extent, and location of properties where structural damage has occurred due to settlement.

A total of 115 lots, including 22 with reported structure settlement, and the approximate location of the former ice pond are shown in Figure 1 (Appendix A). This figure, entitled “Subsurface Exploration Location Plan and Organic Stratum Isopleths,” was originally presented in the HTE Report. An explanation of the information included in this figure is provided in Appendix A.

Two surveys were conducted by neighborhood representatives to determine the extent of damage, if any, that may be due to structure settlement to properties in this area. There was a total of 49 responses with 7 properties responding to both surveys, resulting in a total of 42 properties that were identified in the two surveys. Of the properties identified in Figure 1 that responded, 21 were recorded as reporting structure settlement, and 21 were recorded as not having reported structure settlement. An additional 73 properties are shown in Figure 1, including one property that, although not identified by either neighborhood survey, was recorded as reporting structure settlement. These surveys were conducted from 2004 – 2005, as follows:

• An initial survey was conducted in the fall of 2004 using flyers that were delivered to homeowners in the area. Residents were asked to either email or phone the resident who conducted the survey for the purpose of identifying property conditions that could be attributed to settlement, as well as whether the basement was wet. A total of 22 responses from the subject area were recorded.

• A follow-up survey was conducted in the spring of 2005 at the request of the New Haven city engineer (see Appendix B for a copy of the survey). It was a door-to-door survey undertaken by residents from the area. Responses from property residents were recorded on the survey form by the person conducting the survey. A total of 27 surveys were completed and submitted by the neighborhood representatives to the city engineer.

Only three of the approximately 22 homes that were reported to have structural problems as shown in Figure 1 have been inspected by a professional engineer, the city engineer, who hypothesizes that settlement is the cause of the damage he observed in the houses at 46, 52, and 60 Beverly Road. The owner of the property located at 60 Beverly Road reportedly also had an independent evaluation conducted which included test boring(s).



FINDINGS AND SUGGESTIONS FOR FURTHER STUDY From the limited information provided, the study committee cannot determine any pattern that correlates with the reported structural problems. This includes the initial hypothesis that the settlement is related to the location of the former ice pond, because only about half of the homes reporting structural damage are located within the area where the ice pond was located.

Before the committee can make any geotechnical suggestions regarding proposed remedial methods, such as helical pile underpinning methods as recommended by HTE, it is suggested that consideration be given to performing the following two steps so that the source and the extent of the reported structural problems in the Beverly Hills Development can be clearly understood.

(1) Historical Data of the Site

• Obtain and analyze topographic maps to determine the location of the ice pond, streams, ravines, swamp areas, and wooded areas prior and subsequent to development of the site

• Obtain and analyze aerial photographs of the site before, during, and after construction of the development

• Identify date and sequence of when homes were built

• Identify construction firm(s)/foundation contractors who built the houses

• Obtain and analyze drilling logs from the Wilbur Cross Parkway and commercial buildings that are in close proximity to the development

• Obtain and analyze Connecticut groundwater monitoring data from the Connecticut Department of Environmental Protection and/or the US Geological Survey

• Obtain and analyze reports and/or data from the stormwater investigation project performed by the City of New Haven

(2) Structural and Geotechnical Assessment of Houses by Registered Structural and/or Geotechnical Engineering Professionals. The objective of these house inspections is to discriminate damage caused by undue settling from that which would be expected given the construction methods employed for each structure.

• Examination of houses on 46, 52, and 60 Beverly Road. The city engineer had hypothesized that the damage he observed was caused by settlement.

• A total of approximately 20 houses will initially be inspected. This will include about ten houses that are within the ice pond area and another ten houses that are outside of the approximate location of the ice pond. Within each of these categories (i.e., inside and outside of the pond area), about half will be houses that have were identified has having structural damage. The houses in each of these categories will be selected randomly or by a method indicated by the evidence. If the owner does not give consent to an on-site inspection, then another house will be selected from that category.


AN EVALUATION OF THE GEOTECHNICAL ENGINEERING AND LIMITED ENVIRONMENTAL ASSESSMENT OF THE BEVERLY HILLS DEVELOPMENT, NEW HAVEN, CONNECTICUT FINDINGS AND SUGGESTIONS FOR FURTHER STUDY

• Foundation and structural assessment, including photographs, of the selected houses will be performed using the attached “Report of Foundation and Structural Assessment” form (see Appendix C). This will include the following:

- Description of structure and its structural components

- Identification and evidence of building distress such as cracks, alignment, structural members, shrinkage, and differential settlement

- Evidence of previous repairs

- Settlement around property

After the historical data are compiled and the building assessments are complete, the committee will reconvene to assess the new information. Possible outcomes include the following:

• Assessment of the new data provides sufficient information on the probable cause(s) of structural damage to enable the committee to make suggestions regarding the use of geotechnical underpinning methods (if necessary), as identified in the HTE Report, or other remedial measures as may be appropriate.

• Further data are required to prove/disprove possible cause(s) for the structure settlement. The additional data may include (but are not limited to): more building inspections, test borings, and monitoring of groundwater elevations.



APPENDIXESA

PP

EN

DIX

A

FIG

UR

E 1:

SU

BSU

RFA

CE

EXPL

OR

ATI

ON

PLA

N A

ND

OR

GA

NIC

STR

ATU

M IS

OPL

ETH

S

(Fig

ure

cour

tesy

of H

TE

Nor

thea

st, I

nc.)


AN EVALUATION OF THE GEOTECHNICAL ENGINEERING AND LIMITED ENVIRONMENTAL ASSESSMENT OF THE BEVERLY HILLS DEVELOPMENT, NEW HAVEN, CONNECTICUT APPENDIXES

DES

CR

IPTI

ON

AN

D E

XPL

AN

ATI

ON

OF

FIG

UR

E 1

This

figu

re d

epic

ts th

e Be

verl

y H

ills

Dev

elop

men

t tha

t is

loca

ted

in th

e W

estv

ille

sect

ion

of N

ew H

aven

, Con

nect

icut

. The

fo

llow

ing

prov

ides

an

expl

anat

ion

of th

e in

form

atio

n in

clud

ed in

this

figu

re:

• O

verv

iew

of t

he a

rea

of c

once

rn in

clud

ing

the

appr

oxim

ate

limits

of t

he fo

rmer

ice

pond

that

was

fille

d in

dur

ing

the

late

19

30s.

The

app

roxi

mat

e lo

catio

n of

the

form

er ic

e po

nd w

as d

eter

min

ed b

y th

e of

fice

of th

e N

ew H

aven

city

eng

inee

r us

ing

City

of N

ew H

aven

ass

esso

r m

aps

from

the

earl

y 19

00s,

pri

or to

any

dev

elop

men

t in

the

area

.

• A

ppro

xim

ate

loca

tion

of 9

test

bor

ings

. The

se b

orin

gs w

ere

mad

e in

pub

lic r

ight

s-of

-way

with

in th

e bo

unda

ries

of

the

form

er ic

e po

nd fo

r th

e pu

rpos

e of

iden

tifyi

ng th

e ch

arac

teri

stic

s of

org

anic

laye

rs o

f mat

eria

l in

this

are

a. T

hey

are

depi

cted

by

a pa

rtia

lly fi

lled

in r

ed c

ircl

e, a

nd a

re c

o-lo

cate

d w

ith y

ello

w/o

rang

e nu

mbe

rs id

entif

ying

bot

h th

e to

p el

evat

ion

and

the

thic

knes

s of

the

orga

nic

laye

r in

feet

abo

ve m

ean

sea

leve

l (M

SL) a

t the

test

bor

ing

loca

tion.

Thi

s in

form

atio

n w

as th

en u

sed

to id

entif

y lin

es th

at s

how

the

com

mon

top

elev

atio

n an

d co

mm

on th

ickn

ess

of th

e or

gani

c la

yer

of m

ater

ial,

as d

escr

ibed

bel

ow.

• A

bla

ck “

x” w

ith a

num

ber

next

to it

iden

tifies

the

elev

atio

n of

eac

h po

int d

epic

ted

in fe

et a

bove

mea

n se

a le

vel,

with

a

rang

e of

74.

4 ft

. MSL

– 8

5.1

ft. M

SL.

• Th

e ye

llow

/ora

nge

solid

line

s ar

e co

ntou

rs th

at r

epre

sent

the

equi

vale

nt to

p el

evat

ion

of th

e or

gani

c la

yer

of m

ater

ial i

n fe

et a

bove

mea

n se

a le

vel,

with

a r

ange

of f

rom

71

ft. M

SL –

78

ft. M

SL.

• Th

e ye

llow

/ora

nge

dash

ed li

nes

are

cont

ours

that

rep

rese

nt th

e eq

uiva

lent

com

mon

thic

knes

s of

the

orga

nic

laye

r of

m

ater

ial i

n fe

et a

bove

mea

n se

a le

vel,

with

a r

ange

of f

rom

2 ft

. – 6

ft.

• Th

e di

men

sion

s an

d lo

t num

bers

/add

ress

es fo

r ea

ch o

f the

pro

pert

ies

are

show

n on

the

figur

e. T

he lo

ts w

ith r

epor

ted

stru

ctur

e se

ttle

men

t, id

entifi

ed fr

om th

e su

rvey

s co

nduc

ted

by th

e ne

ighb

orho

od, a

re s

how

n w

ith r

ed h

atch

mar

ks a

cros

s th

e lo

t (a

tota

l of 2

2 of

the

115

prop

ertie

s id

entifi

ed in

the

figur

e). O

f the

22

prop

ertie

s in

dica

ting

repo

rted

str

uctu

re

sett

lem

ent,

appr

oxim

atel

y 12

are

loca

ted

in th

e ar

ea o

f the

form

er ic

e po

nd, w

ith th

e re

mai

nder

bei

ng lo

cate

d ou

tsid

e th

e ic

e po

nd b

ound

arie

s.


APPENDIX B: HOUSE SURVEY

Beverly Hills House Settling Survey June 2005(Note: This is a copy of the survey form that was used to collect information about properties located in the Beverly Hills development of the Westville Section of New Haven)

Name: _________________________________

Address: _______________________________ Phone#: ________________

The city engineer is looking for information concerning your house. Your response will help us better understand what is happening in the neighborhood. Thank you for your prompt response.

1. Type of cellar wall construction:A) concrete B) cinder block C) brick D) stone

2. Does water enter basement? Circle all that apply:A. through wall cracks during rainfallB. through floor during rainfallC. through wall cracks at any timeD. through floor at any timeE. fountain during rain

3. Has first floor settled?A) front B) back C) left side D) right sidedescribe _________________________________________________________________________________________________________________________________________

4. Has your yard settled?A) front yard B) back yard C) not really

5. Other concerns? ___________________________________________________________________________________________________________________________________________________________________________________________________________________

Return by June 27 to: (Note – actual survey form provided name and address of neighborhood representative to return survey to)

If you have any questions, call (Note – actual survey form provided name and telephone number of the neighborhood representative to call for questions)


APPENDIXES


APPENDIX C:

REPORT OF FOUNDATION AND STRUCTURAL ASSESSMENT

AN EVALUATION OF THE GEOTECHNICAL ENGINEERING AND LIMITED ENVIRONMENTAL ASSESSMENT OF THE BEVERLY HILLS DEVELOPMENT, NEW HAVEN, CONNECTICUT APPENDIXES

10 CONNECTICUT ACADEMY OF SCIENCE AND ENGINEERING

APPENDIX C (CONTINUED)


APPENDIXES

2006• Improving Winter Highway Maintenance:

Case Studies for Connecticut’s Consideration

• Information Technology Systems for Use in Incident Management and Work Zones

2005• Assessment of a Connecticut Technology

Seed Capital Fund/Program

• Demonstration and Evaluation of Hybrid Diesel-Electric Transit Buses

• An Evaluation of Asbestos Exposures in Occupied Spaces

2004• Long Island Sound Symposium: A Study of

Benthic Habitats

• A Study of Railcar Lavatories and Waste Management Systems

2003• An Analysis of Energy Available from

Agricultural Byproducts, Phase II: Assessing the Energy Production Processes

• Study Update: Bus Propulsion Technologies Available in Connecticut

2002• A Study of Fuel Cell Systems

• Transportation Investment Evaluation Methods and Tools

• An Analysis of Energy Available from Agricultural Byproducts, Phase 1: Defining the Latent Energy Available

2001• A Study of Bus Propulsion Technologies in

Connecticut

2000• Efficacy of the Connecticut Motor Vehicle

Emissions Testing Program

• Indoor Air Quality in Connecticut Schools

• Study of Radiation Exposure from the Connecticut Yankee Nuclear Power Plant

1999• Evaluation of MTBE as a Gasoline Additive

• Strategic Plan for CASE

1998• Radon in Drinking Water

1997• Agricultural Biotechnology

• Connecticut Critical Technologies

1996• Evaluation of Critical Technology Centers

• Advanced Technology Center Evaluation

• Biotechnology in Connecticut

1994• Science and Technology Policy: Lessons

from Six Amer. States

1992• A State Science and Technology Policy

• Electromagnetic Field Health Effects

1990• Biotechnology (Research in Connecticut)

• Economic Impact of AIDS Health Care in Connecticut

1989• Science and Engineering Doctoral

Education in Connecticut

MAJOR STUDIES OF THE ACADEMY

CONNECTICUT ACADEMY OF SCIENCE AND ENGINEERING179 Allyn Street, Suite 512, Hartford, CT 06103

Phone or Fax: 860-527-2161email: [email protected]: www.ctcase.org

CONNECTICUT ACADEMY OF SCIENCE AND ENGINEERING

The Connecticut Academy is a non-profit institution patterned after the National Academy of Sciences to identify and study issues and technological advancements that are or should be of concern to the state of Connecticut. It was founded in 1976 by Special Act of the Connecticut General Assembly.

VISION

The Connecticut Academy will foster an environment in Connecticut where scientific and technological creativity can thrive and contribute to Connecticut becoming a leading place in the country to live, work and produce for all its citizens, who will continue to enjoy economic well- being and a high quality of life.

MISSION STATEMENT

The Connecticut Academy will provide expert guidance on science and technology to the people and to the State of Connecticut, and promote its application to human welfare and economic well being.

GOALS

• Provide information and advice on science and technology to the government, industry and people of Connecticut.

• Initiate activities that foster science and engineering education of the highest quality, and promote interest in science and engineering on the part of the public, especially young people.

• Provide opportunities for both specialized and interdisciplinary discourse among its own members, members of the broader technical community, and the community at large.

CONNECTICUT ACADEMY OF SCIENCE AND ENGINEERING179 Allyn Street, Suite 512, Hartford, CT 06103

Phone or Fax: 860-527-2161e-mail: [email protected] web: www.ctcase.org

home study 05 15 06study committee that included both geology and geotechnical experts. the...

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