The AFI Vokovice Polyfunctions Center building is primarily an office building offering variable office space solutions utilizing the latest technology. This is a view of two separate buildings of six and eight above-ground floors with a total let table area of almost 14 thousand square meters. These buildings are linked by four underground floors with technical facilities and 285 parking spaces. The architectural design comes from a DAM architect studio.
- Investor: AFI EUROPE Czech Republic, sro
- General Contractor: GEMO as
- Author: DAM architekti sro
- General designer: Atelier Smitka sro
- Construction date: 9/2016 – 7/2018
The buildings have, in addition to administrative areas, space for retail units, gastronomy and storage areas. The project was completed by the general contractor GEMO as in October 2018 and is located in an attractive location of Prague 6, on the border of Vokovice and Veleslavín, within reach of both the city center and the international airport.
Organic shapes, combinations of glass, modern glass-cement and aluminum elements and a roof planted with trees are different from the original buildings once the so-famous chocolate factory. It was founded in 1903 by the siblings of Kroup. Their Chocolate Standard was one of the most famous for Austria-Hungary and later for Czechoslovakia. In the original buildings, the Social Security Administration was also involved.
The construction took place from September 2016 to July 2018 and the first tenants moved in and began to use the building from October 2018. Two building objects were on the investor’s site. The first served social administration and the second as a fitness center. These objects had to be demolished for the construction of the polyfunctional center.
Prior to commencing the demolition of existing buildings and the construction of a new building, it was necessary to carry out the relocation of the engineering networks and to carry out the metro passportation. These networks led through the building site and adjacent roads. This was mainly the transfer of high-pressure and medium-pressure gas pipelines DN300 and DN150, water line DN 500, HV substations for metro and fiber optic cables. The special chapter was the relocation of the single drainage DN 400. The sewer line management should remain in the original position and the direction that intersects the new building at level 3 of the underground floor. Therefore, a passage collector was built in the building and a new sewer line was installed. During the construction of the collector and the underground floors, it was necessary to carry out temporary pumping of the sewer with permanent control of the running of the pumps. After the collector and underground floors were built, the collector was equipped with a glass-fiber pipeline that was connected to an existing sewer. As the new building was in the immediate vicinity of Veleslavin metro station, passporization of the metro tube had to be done. Measuring points were fitted in the metro tube, and geodetically, during the construction, it was observed whether the tube was sedated or cracked.
After dismantling and dismantling of existing objects from utility networks, the building itself was demolished. During the demolition, a parallel archaeological survey took place. On the building site was a chocolate factory at the beginning of the 20th century. In addition, there was a survey on the possible occurrence of contaminated soil.
The demolition was followed by its own excavation and securing the pit. The construction of the building pit was designed as a temporary anchored ramp and an anchored pile wall in the immediate vicinity of the metro. The steel barriers were designed from IPE360, 2 × IPE330, 2 × IPE360, 2 × U300 from S235 steel. Negative spans of 1.7 to 2.5 m. Steel negatives were inserted into bore ∅ 630 mm, resp. double debris into well ∅ 900 mm. The negatives are cemented with C16 / 20 dry concrete, the rest of the well is covered with stabilized soil. The pilot wall is made up of drilled ∅ 900 mm piles at the meeting. At the anchor point, spaces are approximately 200 mm between the pilots. All the piles are reinforced with a round cross armor and concreted with C25 / 30 XA1 concrete. After the establishment of the negatives and the pilot, the soil was extracted from each anchor level. Simultaneously with the mining, the arrangement of the timber was made between the steel cladding of the wooden plinths. 100 – 140 mm and sprayed concrete on the pile wall.
After tightening and raising on the individual anchor levels, temporary spring anchors, drawers, spacers. The anchors are designed from 3, 4 or 5 strands of Lp15,3 / 1770, free lengths 3,0 to 12,5 m, root of 6,0 – 8,0 m. The root section injection was made with 0.5 m cement 2: 1 (cement CEM II / B – S 32.5) with an injection pressure of 2.2 MPa. The anchors were tensioned 7-10 days after grouting. After anchoring the anchors, the soil was further removed after another anchor level.
BUILDING THE OBJECT
The founding of the building is made as flat, supplemented in the place of bigger load or less load bearing capacity of the ground on drilled large-diameter pushed and drawn piles, which emit a monolithic reinforced concrete slab with columns and walls. The piles are made as a lone diameter of 900 mm and 1200 mm. The base plate is a variable thickness of 400 to 600 mm.
Pilots have been used to pump groundwater. These wells were equipped with float pumps for continuous pumping of bottom and surface water. The water was discharged into the drain through the drain well and the measurements.
When designing an object, the building’s protection against stray currents was addressed. The building is located between the European railroad tramway, the SŽD railway line and the A metro line. For the protection of the building, a variant of laying steel wire mesh was selected in the underground concrete, welded and interconnected with FeZn 30 × 4 mm earthing cables 1. PP. The distribution of the NN and the active lightning conductor of the building was also connected to this distribution.
CONSTRUCTION-TECHNICAL AND CONSTRUCTION SOLUTIONS
The bottom structure has three resp. four underground floors. It forms a common unit for both above-ground parts of the designed object. Underground floors reach under the open space at the object “A” and the passage between objects “A” and “B”.
The construction of the lower structure is designed as a monolithic, reinforced concrete structure. Ceiling boards were then non-deflective and, if necessary, locally reinforced at the site of columns and walls with heads. Pillars in underground floors were designed with regard to their load and their location in the construction. In terms of position and operation, they were designed as oval / circular or square / rectangular. The perimeter walls in the basement have a thickness of 250 mm in the 1st PP, in 2 and 3 PP 300 mm and in the 4 PP 400 mm. The perimeter and foundation structures of the lower structure are designed from reinforced concrete containing crystalline briquettes that provide protection for the substructure against ground moisture and groundwater. The bottom structure is dilated between the above-ground parts due to the different seating between the GH module axes. The waterproofing at the site of the expansion joint is ensured by system solutions with respect to stress and anticipated movements in expansion joints, system rails and expansion joints. Work joints are complemented by a certified rehabilitation system. Access to the underground floors is provided by stairs and lifts. The entrance to the garage is from terrain level 1 PP.
The supporting structure of the building consists of a reinforced concrete monolithic skeleton with three or four underground floors and two above-ground sections (“A” and “B”) with six overground and eight above-ground floors. Both above-ground parts have an irregular organic shape of the ground plan.
Horizontal ceiling construction of above-ground floors is supported by continuous walls of communication cores, perimeter pillars and columns. The inner columns are supplemented with sub-ceiling heads. The stability of the object is ensured by a system of walls distributed in the ground plan around the stair cores.
The roof structure is designed as a cross-reinforced slab of about 250 mm thick, supplemented with stiffening ribs 250 mm below the ceiling slab. The roof structure is designed to transfer loads from a green roof with intensive green – with a variable substrate height. Ceiling board above the 1st floor and over the last floor is tl. 250 mm. Other ceiling panels are tl. 220 mm.
Columns, pillars and walls in above-ground floors are designed with regard to their load and their location in the structure. The perimeter walls of object A are in 1 + 2 NP thick 200 mm, in other floors then thickness. 160 mm. The support system of the object B is formed by a regular raster of columns along the perimeter of the object inscribed into the basement of the building. The perimeter columns on object B are in 1 + 2 NP size 500 × 300 mm. In the transitional 3rd floor, where we find a façade, the columns of 990 × 300 mm in other floors are the size of the perimeter pillars of 300 × 300 mm. The pillar on the JV of building B is atypical and transfers the weight of the corners to the lower structure. The wall thickness of the inner support cores is 200 and 250 mm. The acoustic wall on the roof has a thickness. 180 mm and KZS is insulated at the bottom.
In the implementation of monolithic structures, the problem of the shape of the building itself and the connection of individual parts of the monolithic structures to one another, such as walls with window openings which are placed on top of each other, pillars and curved dies, were the most solved. A separate chapter was the solution of the dilation of an object, which is based on different heights. The question of laying the ceiling formwork was also addressed. According to the requirements of the investor and the assignment, there could be a situation that the prospective tenant will not make ceilings in the ponds. For this reason, a layout plan was carried out, which contained a minimum of molded panel boards and the ceilings were realized as visible. Three tower cranes and one concrete tower were used for their own construction, which shifted during the construction as the building itself grew.
Already during the construction of the monolithic structures at the upper floors, work on the facade was started. Each of the above-ground objects has a different façade design. Object A is executed with individual windows / fillings from the Heroal system. The windows are located between the concrete columns and are completely independent of each other. Fillings are split columns and a smaller part of the surface is designed for the system ventilation flap. Considering the thermal and technical requirements, the filler is glazed with an insulating triple glazing. The concrete column between windows is lined with thermal insulation. The insulation is covered with diffusion foil. The pillar walls are lined with glass fiber reinforced facade elements. The element is produced in its entirety, without joints. Anchor of the galvanized steel element, hidden, allowing rectification in all directions.
On object B there are raster facades in the first two NPs. The facade is considered standing and is glazed with an insulating triple glazing. On the other floors the facade is made of facade modules, which were mounted on anchors for both height and directional rectification. Individual “gold” sheet metal fittings were then retrofitted onto individual modules.
The windows and window modules are equipped with exterior motorized roller blinds with guide profiles. Roller blinds are designed to wind up to 90 km / h
ROOF OF THE FACILITY OF THE BUILDING
A walking walkway 800 mm wide for façade and advertisement maintenance is designed around atics.
The roof garden is conceived with regard to the context close to the presence of Wild Sarka. It is designed step-wise to cover the acoustic screen covering the technology in the central part of the roof while allowing a pleasant stay for the users of the building. Plants will also improve the microclimate around the building.
The roof garden on building A is a patio, accessible from the office areas. Green areas are not publicly accessible.
The proposed composition of plants evokes the character of the vegetation of sarka slopes. In the area of the roof garden, similar to the ground floor, plants are planted from several plant floors and a climbing stand of the acoustic screen. Surface protection against increased wind suction effects is ensured by grinding the gravel or crushed stone with a larger fraction.
The green roofs are complemented by the design of the parterre landscaping. Here is an extensive, nature-like vegetation combining the original species and suitable garden cultivars. The terrain is lightly modeled, allowing for the use of different types and sizes of vegetation, from herbaceous herbaceous areas to elevated modeling, allowing planting of medium-crowned trees.
The building is connected to all utilities. Heating of the building is ensured by connection to hot water lines with own exchange station. The cooling of the building is provided by two block cooling units located on the roof of the building and by the accumulation of cold in the engine rooms in the underground floors. Distribution units for cooling, heating and air conditioning are induction units in the office space, and in the lobby areas and retail units, they are fan coil units. There are currently eight air-conditioning units installed in the building to ensure office ventilation, maintenance facilities, retail and storage areas. The underground floor of the garage is covered by a self-extinguishing system that has its accumulation tank located in the 3rd PP. The whole object is automatically controlled by the measurement and control system. Of course, the building is equipped with electronic fire alarm, security, camera, access and parking system. There are nine lifts in the building. The object is designed to hold rainwater and reuse it for greening. All green areas on the building are covered by automatic irrigation.
The object is designed to be certified Leed grade platinum. During the construction, the layout of the building, the possibility of using certain types of building materials with maximum use of local resources was dealt with. The project involved Leed’s specific Leed technology requirements, for maximum energy savings, and for operations as such. The object also has facilities with low water and energy consumption. Temporary protective structures were carried out to cover already finished constructions and technologies. During the animation of the building and during the functional tests, the company was self-certified by the company.