Out of control

The City and its Engineer bid, during the summer of 2005, about 3,200 ft of 36 inch HDPE pipe for a lake crossing to be installed via Horizontal Directional Drilling (HDD) in order that this water transmission line could be put in service by May 1, 2006. On July 14, 2005 when bids were tabulated, Company  X became the lowest bidder at $1,740,000. The second and third lowest bidders were at $2,004,053. and $2,289,400, respectively. The contract completion date was agreed upon as November 1, 2005 at the pre-construction meeting held on August 16, 2005.
The entire, final design and alignment selection were based on only 4 soil borings and no appropriate geotechnical baseline report was ever done or used by the Engineer or their HDD consultant. The driller had so many problems that could have been anticipated even if one of the parties involved in this project spent a few more minutes studying the implications of the 4 soil borings.
The author was retained on November 14, 2007, by the law firm representing the driller, to conduct an independent investigation as to the causes that led to the delay and cost overruns on this project after the driller had been at the site for longer than 1,000 days and had spent over $6 million by their estimate.
Loss of drilling fluids, caving of roads, settlement of houses, buildings, and other calamities were the outcome that the driller, the engineers and the city faced. The lives of local residents were disrupted for many months. There were many lessons learnt and the author shares many of them with the attendees of this conference in the hope similar problems can be avoided in the future.

Background

The topics of discussion as recorded in the minutes of the preconstruction meeting on August 16, 2005 clearly indicate that the engineering firm, its consultant specializing in HDD work and the city’s Board of Public Works presented an over-simplified view of the technical challenges of this project when it came to the choice of pipe material, method of construction, utility concerns, environmental   issues, shop drawing submittals, traffic control, permits, soil erosion and sediment control, testing requirements, resident communication, and settlement monitoring, among others. The design of this pipeline, to be installed by HDD and the site inspection were done by the engineering firm and their HDD consultant, but unfortunately contained errors and omissions.

Documents reviewed and site visit

The author conducted a careful review of the following documents:

1. U.S.D.A. Soil Conservation Survey Maps
2. U.S.G.S. 7.5 minute series topographical maps
3. Geotechnical Borings During March 2005
4. Geotechnical Borings During September 2006
5. Geotechnical Borings During September-October 2006
6. Geotechnical Borings During December 2007
7. Geology of the Region
8. Five of 3.5 inch ring binders of correspondence from December 27, 2004
9. All records related to the loss of drill fluid
10. All records related to the seizing of the pipe
11. All records related to dewatering
12. All records related to jet grouting
13. All records related to pressure grouting
14. City’s Freedom of Information Act documents
15. Preliminary Design Report of April 18, 2005
16. Progress reports by the consultant used as sub by the engineering firm
17. Inspector’s daily reports during November 14, 2005 to January 11, 2006
18. Vibration Studies, Crack Monitoring Data and Reports
19. Groundwater monitoring data
20. Settlement monitoring data
21. Notes on Sink Holes
22. Transcript of a prior lawsuit against the Engineering firm
23. Outstanding issues on February 28, 2007
24. Chronology of Jet grouting
25. Chronology of Vibration monitoring
26. The prime contract
27. Bidding specifications
28. Some photographs
29. Daily job reports
30. 7th Annual HDD Survey By Underground Construction Magazine, June 2005
31. 8th Annual HDD Survey By Underground Construction Magazine, June 2006
32. 9th Annual HDD Survey By Underground Construction Magazine, June 2007

The author also visited the project site and met with the driller’s team during December 2007. Within mere minutes of review of the 4 soil borings, and the line and grade shown on the drawings, it became too obvious to the author that even the most rudimentary details of geotechnical engineering practice had been missed by all parties.

Geotechnical Setting
 
The site is located on the south shoreline of Lake X. The surface geological maps for the State indicate that the site is underlain by Pleistoncene and Holocene sediments containing sand dunes underlain by lacustrian or lake sands and gravels. Most of these lakes on the fringes of the eastern side of Lake X result from down cutting  of  rivers when  Lake  X  dropped  hundreds  of  feet  around 10,000 years ago. Glacial retreating gradually brought the lake level higher about 5,000 years ago when inlet incision lowered the level to its current position. As a result, the lake is a drowned river valley that gradually filled  in  as  the  Lake  X  water rose higher. Similar to most lakes, a bay mouth bar kept the lake slightly higher than the water level in Lake X.
 
There were four sets of geotechnical borings that were done as follows:

a) Geotechnical Borings during March 2005  
 
The design of the project was based on only two soil borings on land. These borings were done in March 2005 and reported in May 2005. These two soil borings
encountered sand and silty sand with overlying sandy silt with some lean clay at
deeper depths. Clay and silt lenses were encountered within the upper sand and silty sand. Silty sand was encountered within the sandy silts. Sand seams and gravel were encountered within the lean clay. The sand and silty sand were medium dense to dense, the silt was stiff to very stiff and the lean clay was stiff to hard in consistency. Slightly shallower water tables were encountered in the land-side borings at about 579 ft compared to the water level in the lake being at 578.6 ft.  
 
Two additional borings were conducted from a barge into the lake bed. Test borings in the lake showed that the soils are primarily sand and silty sand near the surface underlain by soft under consolidated and normally consolidated sediments. There were also gravel lenses, very soft organic silts underlain by medium dense to silty sands. There was also lean clay with some cobbles at deeper depths.   
 
Bed rock depth ranged from 450 to 500 ft in the region while even at boring depths of 485 ft no bed rock was encountered among the 4 borings  done  for this project. The above geotechnical data was found to be inadequate by the driller, the engineering firm and  their  HDD  consultant, and the Board of Public Works  when various technical challenges surfaced. Unnecessary technical debates broke out numerous times even on scientific knowledge widely accepted and have been part of standard geotechnical
engineering practice.  
 
Due to the fact that the original soil borings of March 2005 simply did not provide
sufficient data on how to settle such debates, additional geotechnical investigations were carried out during September 2006, September–October 2006 and December 2007 as follows:

b) Geotechnical borings during September 2006  
 
Eight soil borings were performed on the south side of the recovery shaft with boring depths ranging from 30 to 45 feet. The soils consisted of sandy fill overlying fine silty sand to depths of about 30 to 38 feet. The sand was very loose to medium dense. The very loose soils were generally encountered between 15 to 30 feet. At one boring performed near the recovery shaft and above the steel casing installed for the last 100 feet of the 3,200 ft long HDD drive, the sand just above the casing appeared to be mixed with bentonite drilling slurry. Below the silty fine sand, a sandy silt-silty sand with clay seams and layers were encountered to a depth of 45 feet. These soils were generally medium dense to stiff in consistency. Cement grout was encountered in a few of the eight borings closer to the recovery shaft. Groundwater depth was between 12 and 13 feet from the ground surface. The GeoProbe rig, used on the north end of the recovery shaft, located HDPE pipe that gotten stuck.

c) Geotechnical borings during September-October 2006  
 
Twelve soil borings were done to verify the geotechnical investigation that was done
during  September  2006  and  thus provide data quite similar  to what was already
collected. It is unfortunate that the engineering firm and their HDD consultant ordered these 12 soil borings and associated geotechnical investigation and had the Board of Public Works pay for these somewhat too late in the process of characterizing the site conditions. If indeed all of these data were collected by the engineering firm and their HDD consultant in advance of designing the project to avoid an experimental HDD 3,200 ft long drive with 36 inch HDPE pipe, the intended water transmission pipe could have been designed and built much faster and more economically with better pipe material using some other construction method with a proven track record.

d) Geotechnical borings during December 2007

When it was suspected that there was the possibility that a deeper aquifer was feeding the groundwater to cause sand boils, making dewatering of the recovery shaft ineffective and unsafe for the workers, a fourth set of soil borings were done during December 2007. In the first soil boring at piezometer location #300, a clay layer was encountered from 37 to 48.5 feet underlain by silty fine sand to depth of 61 ft. From 61 to 67 ft, sandy silt was encountered over silty clay. At the second soil boring where the second piezometer #301 was planned to be installed, silty fine sand was reported from 37 to 55 ft with some silty clay. Loss of drilling mud, causing the HDPE to seize during the September 2005 installation, occurred between 45 to 50 feet in the first soil boring where piezometer #300 was planned and from 35 to 40 ft at the second soil boring where piezometer #301 was planned. Groundwater levels during drilling were observed at depths of 15 to 20 ft at these two soil borings. The standard penetration test blow counts were from 44 to 58 in sandy silts and 8 to 13 in silts and clays. When the tips of the piezometers were set at about 69 to 70 feet with 20 ft long screens, a lower aquifer was detected providing a rational explanation for a major groundwater anomaly that contributed to the loss of drilling fluid during September 2005, seizing of the HDPE 36 inch pipe about 150 feet short of its target, and excessive amount of water entering the recovery shaft during the driller’s repeated good faith efforts to dewater the recovery shaft adequately to be able to complete the project.

Evaluation of Engineer’s Preliminary Design Report
 
It became quite clear while examining the engineering firm’s preliminary design report that the engineer of record simply did not have anyone on their staff with the appropriate qualifications and experience to handle the challenges of this project. The decision to go with HDD as the construction method for the lake crossing was based on two land-based geotechnical borings named LB-1 and LB-2 taken during March 8-10, 2005. The route evaluation was based on a site visit by their HDD consultant on November 29, 2004, utility mapping data and aerial imagery. Potential drilling fluid loss and associated road heave or settlement, and the risk of impact to be reduced by setting surface casing during construction to contain drilling fluid, were all considered. Although an open cut construction alternative was estimated to be cheaper, this construction option was never offered to the bidders.   
 
Despite the fact that the design team and the Board of Public Works were aware of potential construction problems using HDD compared to open cut construction, the preliminary design report contained in one section; “Open-cut trenching, directional drilling, and bore and jacking are all methods which can be used to construct the proposed transmission water main. Of the three options, open-cut trenching is the least expensive, provided space is available. Given that sufficient space exists along all portions of the land based route for open cut trenching, this is the recommended installation method”. In another section of this report; however, the engineering firm wrote “Based on the results of two geotechnical borings, it is our opinion that subsurface conditions are conducive to the HDD process.” The geotechnical borings showed loose cohesionless soils yet the engineering firm’s report contained; “It is probable that loose cohesionless soils will not support an open hole over a long horizontally drilled length. This does not, however, prevent the installation of a pipeline.” The engineering firm’s report also contained “The technical feasibility of a proposed HDD installation is governed by three basic parameters: drilled length, pipe diameter, and subsurface material. These three parameters work in combination to limit what can be achieved at a given location.” When the engineering firm discussed the risk associated with subsurface conditions, they added “While length, diameter, and subsurface material work in combination to limit technical feasibility of an HDD installation, technical feasibility is primarily limited by subsurface material.” The engineering firm also wrote “Soils consisting principally of coarse-grained material present a serious restriction on the feasibility of HDD.” Gravel was encountered, however, in the geotechnical borings but was somewhat ignored by the engineering firm and their HDD consultant when they were negligent with the choice of the construction method of HDD.  
 
It is also important to point out that there were no other projects with a drive as long as this crossing which required 3,200 feet with 36 inch HDPE (setting a record in the world in 2005). Although steel pipe was considered, this option was never offered during the bidding process. In essence, the engineering firm’s work was somewhat experimental, did not rely on an adequate geotechnical baseline report of any sort, and lacked an adequate standard of care that a comparable firm would have afforded to the owner and the project when it came to such a complex project. Even the brief geotechnical report based on only 4 borings contained the words “Gravel and cobble material were encountered within the clay till. The contractor must be prepared to drill through and manage such conditions where encountered.” It is ironic that the brief geotechnical report is dated May 2005 while engineering firm’s preliminary design report was done on April 18, 2005, ahead of geotechnical findings, implying that the engineering firm and their HDD consultant simply went through a motion of doing the very minimum geotechnical exploration work on establishing the subsurface conditions and simply did not rely on even this little data to decide on the construction method it chose for this lake crossing. The preliminary design report talked about needing extreme care when the drill path crossed under the petroleum line, yet no performance criteria were presented for allowable construction-induced vertical and horizontal movements of the petroleum line.

The engineering firm’s and their HDD consultant’s lack of geotechnical and pipeline
engineering experience and their improper choice of HDD for the construction led to numerous problems throughout the construction phase of this project. It is ironic that the negligent conduct by the engineering firm and their HDD consultant during the design and construction phase resulted in increased billable hours and out-of-pocket reimbursement paid to the engineering firm and their HDD consultant from the Board of Public Works.

Evaluation of Specifications

The specifications were flawed in the following aspects:

a) HDD for a 3,200 ft long 36 inch HDPE, in the subsurface conditions encountered at this site, is not an appropriate construction method for the line and grade chosen.
b) While subsurface conditions govern the success rate of HDD, the engineer and the Board of Public Works never obtained sufficient geotechnical data during the design phase of this project.
c) This led to specifications not having adequate provisions for settlement monitoring, vibration monitoring, crack control, groundwater monitoring and quality control tests.
d) Specifications never accounted for the presence of deeper aquifers.
e) Specifications did not contain engineering criteria for meeting settlement monitoring, vibration monitoring, crack control, and groundwater monitoring.
f) Due to the significant lack of sufficient geotechnical data during the design phase, several additional geotechnical investigations had to be done when various unanticipated construction problems surfaced adding further evidence that the specifications that were bid were flawed.

Actual Conditions Being Different From Those Known at the Time of Award
 
The geotechnical conditions the driller faced at this site were dramatically different from those represented by the design team. The design team simply completed the design drawings and specifications and bid the project in a hurry. By doing so, the design team passed on their risk to the driller knowing that there would be problems during the construction phase. No one among the Board of Public Works, engineering firm, their HDD consultant, and the driller really understood the geotechnical engineering data on hand and the challenges they faced at any time during theentire period of this project.

Excessive Involvement of the Engineer and Use of Arbitrary Performance Criteria
 
The language in the Contract DIVISION 00 GENERAL CONDITIONS ON PAGE 00706 – 7 REV.06.29.2005 defined the engineer’s status as follows:
 
“The engineer shall have general supervision of the work. He has authority to stop the work whenever such stoppage may be necessary to insure that the finished work will be in accordance with the plans and specifications. He shall also have authority to reject all work and material that does not conform to the plans and specifications.“  
 
By using the above clause, the engineer was involved essentially on a daily basis, directly and excessively in controlling the means and methods chosen by the driller. The engineer delayed the execution of this contract by the driller by not being cognizant of the body of engineering knowledge on pipeline materials, design and construction. The engineer also was not familiar with national standards and codes and about the widely accepted engineering practice of underground pipelines made of various materials and constructed by different installation techniques. The engineer also was not familiar with the state of the art of performance criteria on allowable settlements of residential structures and buried pipelines, allowable vibration induced effects on nearby structures, allowable crack widths in residential buildings, effects of dewatering on settlements, and other. Because of the engineering firm’s and HDD consultant’s lack of adequate engineering know-how on all of the above, protracted technical debates during meetings and in correspondence ensued, severely affecting the rate at which the driller was authorized by the engineering team to proceed with the means and methods the contractor chose. Every performance criterion that the engineering team used to either accept or reject among the means and methods or finished work by the driller, had to be debated and agreed upon often in an arbitrary and highly stringent nature without any engineering merit or national precedence. It is quite clear from the record that when the driller bid the project, he was totally unaware that any of these performance criteria would be introduced day-to-day by the engineering team in order to either accept or reject work. This situation posed a new set of conditions that were unknown at the time of the award of the contract.
 

Change of Scope

The engineering team completed an experimental design using a highly risky HDD construction method based on insufficient knowledge about the subsurface conditions and they ignored the caution shared among experienced geotechnical engineers nationwide on HDD technology regarding its limits and about the inappropriateness of HDD as a viable construction method for such a long (3,200  ft) 36 inch HDPE lakecrossing. The engineering team also set aside their own geotechnical subconsultant’s guidance based on even the limited soil boring data that showed problematic gravel seams, cobbles, and extremely loose deposits of granular material with very low blow counts even without the 140 pound hammer hitting the stem of the split spoon sampler around the location where loss of drill fluid and subsequent road collapse occurred.
Even as early as in April 2005, the engineering team knew that HDD would not be an appropriate construction method, would carry higher risk and would cost more compared to an open cut option yet, on behalf of the Board of Public Works, bid a set of specifications that were flawed, overly broad and with no specific performance criteria for the driller to meet on many accounts. The engineering team entered into numerous time consuming technical and procedural debates with the driller about even the most rudimentary engineering principles that had been settled in national engineering practice. The engineering team changed the scope of work numerous times by setting arbitrary performance limits that are not widely accepted within the engineering practice.

Engineer Dictating Means and Methods
 
Right throughout the project, the engineering team had taken numerous actions dictating the means and methods it allowed the driller to use for construction work on this project.   
 
Engineer Interfering with Contractor’s Subcontractors
 
The engineering firm, in an overzealous manner, even interfered with the driller’s
attempts to negotiate and subcontract work as part of its ongoing good faith efforts to complete this project expeditiously.

Summary

The following opinions were formed in this independent investigation:

1. There is sufficient evidence that what the driller faced at the job site, in its dealings with the engineering firm and their HDD consultant, and the Board of Public Works, were materially different from their representations when the project was awarded.
2. The design is defective in many aspects. As a matter if fact, the author was never able to obtain an acceptable set of design calculations from the engineering firm, their HDD consultant, or the Board of Public Works, given the problems with the choice of plan, profile, pipe material choice, etc. that the driller faced at this job site.
3. The Contract technical specifications were defective. The engineering firm, their HDD consultant and the Board of Public Works, either due to lack of sufficient expertise or deliberately, left out the performance targets in the bidding specifications but chose to delay the progress of the driller by enforcing changing specifications with performance targets that were overly stringent, arbitrary in nature and without any engineering merit.
4. The nature in which the engineering firm, their HDD consultant and the Board of Public Works kept changing the scope of work is significant.
5. There is ample evidence that not only the Board of Public Works, but the engineering firm and their HDD consultant decided to force numerous means and methods on the driller without ever affording the public to benefit from the driller’s expertise. The engineering firm, their HDD consultant and the Board of Public Works sometimes forced incorrect methodologies on the driller, which resulted in additional delays.
6. The selection of suitable materials and construction methods for underground pipelines does not happen by accident. It requires decades of experience and sound knowledge of geotechnical engineering practices and pipeline engineering and good judgment derived from having worked on hundreds of similar projects.