Oil Depot Renovation Project

Hello all, this is Arthur again.  We went to the oil depot. The owner of the depot is a successful engineer and great business man. Due to the recent market competition, the owner of want to recover one of the old station they abandoned for three years and renovate the systems. It was started in January and has most of the work. We get a chance to take an adventure going into one of the new tanks almost finished.

Differed from most infrastructures, the petroleum tanks do not have a foundation. The tank was sitting on a solid concrete platform. Between the concrete and tank, there is a layer of sand. So when the tank was full of petroleum or expand during summer, the bottom of the tank will bend without damage of the tank. And the bottom of the tank will The tank build from pieces of 5 cm thick iron plates. Due to the nature of the thermal expansion, they would expand under long time sun exposure and shrink during the winter. During the summer, they will cool the tank using water spray from outside of the tank. The water stored in a reservoir and supplied from the blue water line. The tank is different in the States which we would have to use concrete double walls with a positive separation to prevent any environmental hazard.


The Orange( red ) line connected to the tank is for emergency fire extinguishers by spray foams. Although there is never a fire accident happened on the site, the owner still needs to upgrade the lightning system. The grounding line from the Lightning system would be the only connection between the tank and soil.

During the 1970s oil crisis, the former owner of the station come up several irrational solutions to deal with it. One of those solutions is by adding more water into the tank to dilute the petroleum. These unethical methods only bring a short term profit, since then the tank was oxidized critically because of the water. Therefore part of the renovation is to clean up the rust and apply a new layer of Epoxy inside of the tank. Epoxy provides a great isolation metal coating.


The owner of the oil depot showed us a critical section been recovered. (See the wrinkle on the tank) The specific heat of the iron is about one tenth of the water. These iron tanks naturally expand after long exposure to the sun. Also, it would shrink during the winter. The iron plates fatigued after years and part of the tank failed and bent inward permanently. What they did is put on three support beam to force it rebound and prevent further damage.


The owner always put the customer as his priority. He paid million dollars to renovation. The petroleum supply is fully computer controlled the unmanned system to shorten the time and precisely control the supply. That would bring up the efficiency of the petroleum distribution lines.  Besides, they also restart the petroleum recycling system. It is a machine which would filter the gas from the fuel tanker to capture any leftover petroleum from the gas stage. Although the owner has to pay more than what would he gain from recovered gas, he still willing to do so in the matter of sustainable development. He also utilizes geothermal bump in the new office.

Single Family Houses, Marinski Ltd.

Hi, this is Arthur again. We went to a privately owned site in an upscale neighborhood on Tuesday. The whole project actually contains two individual houses. One of them just finished up with the foundation. The other one is preparing for pouring the beam on the second floor. In this blog, I will continue to compare the different methods being used for the construction management and engineering in practice within different countries.


First, I want to introduce the owner of the company, Marinski, and talk about what he does differently in the field of construction management (CM) from the States and China. Marinski has a high criterion of his project, dedicate in the projects he does and takes care of his employees. He would do those projects he likes. He loves small size crew of 60 including the construction workers and only takes few projects at same time.  He trains each worker by himself and keeps them as full-time employees. He offers them a one-month break during the new year on top of their annual vacation.  Similar to the States, nobody works during the weekends. It’s different in China, construction worker usually has to work every day except few days’ vacation for the Chinese New Year. Employees in Marinski Ltd. get paid well. They get paid for each stage they finished as an incentive. We would never have that in the States. Marinski also invented his own management software to tracking the materials and equipment in the warehouse. Bulgaria does not yet have a reliable CM software, such as the Procore we often use in the States.

In the construction site, safety is always the first concern. However, in the Marinski Ltd, they only had one accident in the past ten years. One the worker got into a car accident on the way back home. In Bulgaria, the company takes all the responsibilities for anything happens to the employees during the transportation to the work and back home. The company also provides steel-toe shoes and hard hats, as well as daily safety instructions. When the temperature rises up to 35c any exterior constructions has to stop. Unlike in the States, we would continue the construction but offer more breaks during the work. However, the staff work with the concrete did not have their mask on, which is required in the States. Also, they did not have the protect from the height, which is required in China. We would have a decorated wall covered the construction site, and cover the building with a special polymer net.  Not only for the protection of the construction workers falling down, but also prevent anything drops from the height to hit anyone else.

DSC04177 (2) - Copy

Now, I will introduce the project we visited. The owner of the house want wants the Marinski Ltd to help him building two additional houses for his child on his land. Similar to the most Europian and Asian Country, it is really common in Bulgaria, that parents would take care of their children’s houses and they usually live close to the family, which is not typical in the States. The project involves massive concrete and brickworks, which differ from the typical wooden structure from the northern America. One of the reasons is the typical timber produced in Bulgaria is too soft to support the loads.


One interesting feature is that the project was enclosed by planks with dozens of nails on it.  Those nails were not placed randomly. They represent the ground level and the orientation of the columns. Those magic nails were placed by geotechnical engineer and surveyor after excavation. They would connect each two pairs of nails by orange wire, and each cross of two wires are the center of a column. Therefore, the positioning and leveling of the foundation and columns are easily done. In China, survey usually would come after excavation and label the center of the piles. The contractor would trust the drillers do the work, most of the time the error is negligible. In the States, Caterpillar invented Terrian™ and ACCUGRADE™ systems for drilling and excavation.  It using GPS, GNSS, laser and ATS technologies to precisely control the process and minimize the degree of accuracy, meanwhile increases in productivity up to 40 percent.

DSC04181 (3) - Copy

Addition to the magic nail they used, they also have some magic joint connect the steel forms for the foundation. There are four joint inserted between two feet long steel plates and joined by huge bolts. Therefor the form would firmly connected and minimize any displacement or potential failure during the vibration process. The joint will leave inside of the concrete, and the workers will bend it to the side and cover with another layer of stucco.

DSC04169 - Copy

EU has very strict regulations on the new buildings under constructions. For the exterior walls, the minimum width is 35 cm which is equivalent to 14 inches. And the interior wall has to be wider than 15 cm. Marinski recommended to his client use thicker bricks for the interior too for the best thermal insulation. The concrete they used is C20_25, which has a bearing capacity of 3600 Psi. That is similar to what we use in the States.


Overall, the Marinski Ltd does a great job in the construction. Especially, on the safety and some unique construction methods they used are practical in the States and China, such as the magic nail. I would like to implement those into my future career

Ancient Roman Structures, Plovdiv.

Hi, I am Arthur, Qiming Wang, senior Civil Engineering student at Syracuse University. It is my great honor to travel with professors and peers from SU and Utica College. We are now in Plovdiv about 3-hours drive east from Sofia . We enjoyed the one-day tour in two historical sites from Philippopolis. We were interested in how the stairs are evolved over time. I was amazed by the technics used by ancient Romans in building and infrastructure.


The first site we visited is the Ancient stadium of Philippopolis, also known as the Ancient Roman Stadium. The stadium was built with marble blocks from 2nd Century AD. It could seat up to 30,000 spectators almost the 2/3 capacity of the Yankee Stadium. The dimension is 240 meter (820 ft) long by 50 meters (164 ft) wide, have an area more than two of American football court.
LRM_EXPORT_20160730_151033 (2)

The other site we visited is the Theatre from Emperor Trajan in a shape of a semicircle. It is so spectacular although it was seriously damaged and only partly recovered. The stages, scaenae, have three floors supported by ionic columns, with a pediment with incredible sculptures. The stand, cavea, has been restored with about 3500 seats, which is nearly half of the original capacity. There is an annual summer concert host in the theater, we are going to see in the next few days.


Also we passed by Hisar Kapiya, an arch represent the stonework and brickwork of ancient Philippopolis. It was founded from Roman Age and be destroyed and reconstructed several times.  Arch are wildly used not only as a architectural element but also structure stiff  to transfer tremendous loading. The smaller entrance for the stadium on the north has been recovered. It is a small tunnel supported by a barrel vault. A barrel vault is an extended arch with multi keystone on the top, which we call the crown. The crown transfers the weight to rest of the vault- haunch, then transfer to the buttress on the side.

Roman Stadium-Barrel Vault

The masonry structured used a lot of Mortise and Tenon Joints. The stones are crafted in multi-faceted, with dent and protuberances. It has been wide used crossed the world. Traditional Chinese timber architectures often use Mortise and Tenon joints to make the structure support. Ancient Romans developed the melting iron and locking method to reinforced the marble structures. They drilled a hole through two stones pour melted iron into it to provide extra support and connection. Later on, they discovered that lead cover would help to keep the iron from rust.


We tape measure the stairs from both stadium and theater, and contemporary stairs. We found things are evolved dramatically. The average rise of the stairs in the stadium was 20.150cm (7.93 inches). It is almost one inch longer than the US stander 7 in. The run of the stairs varies from 15.5 cm to 56 cm. The rise and run of the theater are close to the modern system.

Tape Measure of the Stadium

  Tape Measure - Theater

Wise Romans implement drainage system on the street. The street of Philippopolis have concave dihedral pavement, and a narrow gutter run through the mid. Precipitations will be collected by the gutter from the sloped pavement, and run down the hill.


Roman Stadium - cavea

Roman Stadium- View from South, Portrait

LRM_EXPORT_20160802_174323 (1)