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Description

Calculate the average cycle times for the different steps of the operation, and explain the
reasons for the variations. Did the operation have any unexpected difficulties or obstacles?
• Calculate the productivity based on the soil and equipment characteristics using the methods
we learn in the course.
• Compare your calculations with the actual productivity.

Table of Contents
1. Describe the Earthwork Operation
2. Reasons for Design of Operation
3. Calculate Productivity
4. Analysis and Recommendations
Figures
1. Haul Route Logistics
***Lakrori’s Comments
Hi team,
I reviewed the first few sections of the draft and this is what I noticed (please go back and review the paper with the
syllabus in hand to ensure you don’t miss anything important). Please note that I didn’t look at the whole submission
as I don’t grade the drafts. But the following should help guide you in the right direction:
Although you have started working on the project it seems to be very far away from its completion with entire
sections left completely blank.
Just like CONE 280 make sure to break the sections in smaller, more legible/defined paragraphs.
MUST Include figures/photos from site visit.
Any unforeseen conditions?
Don’t use personal pronouns such as ours, we, I in a technical paper. Rather say ‘the group’, ‘the project’,
‘the team’ etc.
Elaborate on the haul routes, also show schematic, graphic.
How many crew members in total? Make sure to reference all your sources at all times.
References missing and calculation section is lacking. Show all calculations (include in the appendix if you need to).
What tables/equations/logic was used. This is a big chunk of the project.
SLIDES ARE MISSING FROM THE SUBMISSION
1. Describe the Earthwork Operation
Overview
Sundt Construction is responsible for the complete overhaul of school, Emerson-Bandini
Elementary. This project is located southeast of Downtown San Diego and more
specifically is located on 3510 Newton Avenue. This project includes the demolition of
all existing buildings on campus except for the multipurpose room which will receive a
remodel. Some of the new construction includes but is not limited to, a two-story
classroom building, a small wing for special education, kindergarten facilities and an
administration center. This project is estimated to cost around 56 million dollars and is
60,000 square feet total. The earthwork and grading subcontractor is FJ Willert. Some of
the other project participants include Davy Architecture, design consultant Kurt Hunker,
and concrete technician Michael Allen. This project underwent demolition in June of
2019 and is expected to be completed by the end of 2021.
The desired soil characteristics for this project called for a density of 126 lb/cy.
This ensured that the foundation would be able to support the load of the new
construction. The soil borrowed had a density of 121 lb/cy which meant they had to add
water. The concrete technician Michael Allen explained to us that this project required
the soil to be 2% over the optimum moisture level. They used a mechanical compaction
once the soil was put in place to increase its strength.
The haul route for the stripping operation was a ¼ mile or 1320 feet, since the soil
was dumped at another area on site. The amount that was imported to the site daily was
around 2,000 cy. In total they imported 10,000 cy to the site and used 3,000 cy from an
existing stockpile. In terms of equipment, they used 6 super-10 back dump trucks and 1
excavator, 3 dozers, and 6 belly dump trucks . The super-10 trucks were used in the
stripping operation for relocation. These trucks are great due to their ability to maneuver
well. The downside to this of course is that they are smaller in size. The trucks used for
import operation were belly dumps.
Sundt also took many steps in ensuring the safety of their crew. They made sure
that everybody had their PPE on which includes high visibility vests. Other safety
measures include using backup alarms, making eye contact with operators, using hand
signals, and hiring only professional truck drivers.
The superintendent also made sure to warn us about the dangers of public roads.
They would make sure to do traffic control whenever the trucks were leaving or entering
the site to help mitigate the risks.
Some of the difficulties for this project were space. In order to combat this, Sundt
would limit the amount of soil that would come in daily. This ensured that they would not
have extra soil laying around, wasting valuable space.
2. Reasons for Design of Operation
The first operation that was conducted, was the stripping and export of approximately
3,000 cy of unsuitable soil. The original soil characteristics contained too much clay, so it was
determined by NV5, the geotechnical engineer of record, that suitable soil must be imported to
the site. The stripping operation was conducted using 3 wheel dozers and 1 excavator. The
medium sized dozers were used to effectively clear demolition debris from the site, remove
layers of soil, and push the soil into 2 large separate stockpiles. The excavator used a hydraulic
backhoe to over excavate unsuitable soil for the 6 foot deep foundations of the 2 buildings.
Overexcavation is the process of excavating beyond what is necessary for the footing dimensions
and backfilling with suitably strong soil for the foundation. The excavator, with an average
bucket heaped load capacity of 3.5 cubic yards, was used to build and maintain the stock piles as
well as loading the trucks for export. In order to maximize efficiency and productivity, the
contractor decided to reuse the soil on a different part of the site where the soil does not need
structural bearing capabilities since a play field will be built there. This allowed for a haul route
of .25 miles long or 1320 feet.
The haul route distance and dumping site area were factors of the basis of selection for
the type and amount of the trucks used. The dumping location was much smaller than the loading
location. The dumping area had only one opening for entrance/exit and was the width of one
truck. The tight maneuvering logistics, a public road haul route, and the short distance is why
Sundt decided to use super-10 rear dump trucks for the export operation. The operator and truck
drivers worked for 3 full days, with a standard 8-hour workday at an efficiency of 50 min-hours.
The contractor used basic load capacity and haul distance information to estimate cycle times,
and they were able to determine that 6 trucks with a 12-15 cubic yard capacity each would be
used. However, the superintendent from FJ Willert is so experienced in earthwork operation that
he can estimate the duration and equipment necessary for large operations by just imagining it.
He has memorized the cycle times of all of their machines. The operators and crews are selected
by FJ Willert, the earthwork subcontractor. Operators are selected based on their level of
experience and their availability. Since this is a public works job, there is a smaller pool of
union approved operators.
The subsequent major earthwork operation that was conducted was the import and
grading of 13,000 cubic yard of soil. The contractor used 3,000 cubic yards of suitable soil from
an existing stockpile onsite. The other 10,000 cubic yard of soil was imported from a different
construction site that FJ Willert was working on. There were a couple different sites that the
contractors were considering to gather soil from. However, there was only one site, located near
Downtown San Diego, that NV5 approved the soil characteristics from. This location was
approximately 3 miles away from the site.
For this operation, there were 6 belly dump trucks utilized for hauling and dumping the
import material. Belly dump trucks were used because they have an average of 24 cubic yard
capacity and they are effective in quickly dumping and spreading a large amount of loose
material. The site import location had a lot more open space for truck maneuverability. And the
entrance/exit was large enough for two trucks to pass through together. Therefore, to minimize
the amount of loads, the contractor decided to use the largest truck possible for the size of the
site. There were two dozers and two motor graders used to spread the loose import material.
Unfortunately, the type of equipment used for loading and its cycle time at the export site is
unknown.
Calculate Productivity
We have two different earthwork operations that we are going to be calculating
cycle times for.
1. One cycle time is for the stripping and export operation. The contractor needed to
remove approximately 4,500 cy of unsuitable soil from where the structure will be
built on. This operation consisted of six super-10 dump trucks and one excavator.
This operation lasted 3 days.
2. The other operation we are calculating cycle time for is the import of
approximately 13,000 cy of suitable building soil. This operation lasted about 6
days. This operation consisted of belly dump trucks, dozers and graders.
4.Analysis and Recommendations
In this project, Sundt Construction needs to plan hauling and returning
from other places with the distance nearly 0.25 miles. During the hauling time
and returning time, the workers would spend not only for the working time but
also for the unproductive time. The unproductive time may be the time waiting for
the equipment for work areas to be ready or the material hauling to the work site.
For example, workers would spend only 50% of their time on direct work and
another 50% of worker time spent waiting for unproductive time. When the
unproductive time takes place, the workers would be required for overtime.
Excessive overtime can result in fatigue, higher the accident rate or worker
turnover which can damage productivity. In other words, reviewing and realigning
daily workflows is necessary for the general contractor to see the real productivity
changes in the site and avoid the unproductive time. For doing this work, the
Sundt Construction must establish a team in this project. For this team, the
workers can measure the logically sized crew and the staff hours to meet the
logical production rates. That is the key to save the labor cost.
In construction, good communication can improve the work team and the
productivity. If the architect, the general contractor, and the subcontractor can
communicate clearly from starting to ending, the addendum will minimize. BIM
(Building Information Modeling) can be the necessary tool for Sundt when it
makes sure communication is clear and constant . The general contractor can
solve two problems relating to productivity with one system. First, BIM helps
Sundt Construction to cut down on project organization, setup, and logistics
timelines, since BIM provides the information which a construction project should
look across its entire lifecycle. Next, BIM allows for everyone to access into the
system. That can help the staff to follow their work without the
miscommunication, confusion, or lack of direction from supervisors. That is one
of the ways to improve the productivity in the project.
Haul Route Logistics
National Ave
Dumping
Area
S 35th St.
Entrance/Exit
Stripping/
Import
Area
Haul/Return Distance: 0.2 miles
Entrance/Exit
Boston Ave.

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