In addition to the highlighted projects, we have a series of other successfully completed collaborations that demonstrate the consistency, quality, and professional approach in our work. Below is an overview of additional references that further confirm our experience and dedication to every client.
OTHER
Based on the proposed Program of Geological and Geotechnical Investigations and Testing for the needs of the G31 geotechnical mission for the regional landfill “Separation 1,” investigative works were carried out at the site between November 2020 and May 2021.
At the locations of future structures, exploratory trenches and dynamic probing using the medium-heavy Dynamic Probing Meter (DPM) were conducted, and exploratory drilling was performed within the landfill body area.
The G31 mission defined the foundation conditions for the planned structures, landfill body, as well as temporary and permanent roads.
The entire section from the connection to M6.1 up to WF Mesihovina is divided into three subsections:
Before starting the Detailed Design, a Geotechnical executive study, namely mission G31, was prepared. The G31 mission, as a Geotechnical executive study, presented and recorded deviations of actual site conditions from those anticipated in the Main Design, and proposed adjustments and modifications to the design solution, which were fully respected during the preparation of the Detailed Design.
As part of this contract, the Detailed Design for crane platforms at the locations of all wind turbines (WT1 to WT22) was developed.
The project aimed to find the most economical solution for landslide remediation, complying with technical regulations, by addressing drainage, construction of structural elements, track rehabilitation, cleaning of channels and culverts, screening of the protective prism, removal of grains smaller than Ø 31.5 mm to the landfill, supplementing the protective layer with new material, replacing damaged sleepers, track alignment, and restoring designed speeds on the rehabilitated sections. Landslide remediation projects were carried out at several locations:
Railway 12 Bosanski Šamac–Sarajevo, between Maglaj–Jelina stations
Railway 12 Bosanski Šamac–Sarajevo, between Lašva–Alipašin Most stations
Railway 14 Brčko–Banovići, between Bosanska Bijela–Banovići stations
This project includes:
As a result of this project, a revised and comprehensive set of information was produced, covering landslide locations, terrain susceptibility to sliding, terrain stability categories, suitability of the terrain for construction, seismotectonic characteristics of the area, critical zones from a spatial planning perspective, planning and construction conditions for different terrain categories, and, ultimately, a digital graphical and textual database within a GIS environment.
Geophysical surveys are a set of methods used to investigate the composition, structure, and characteristics of the Earth’s crust without direct excavation or drilling. They are based on measuring physical properties of soil and rock, such as density, magnetism, electrical conductivity, and the propagation velocities of seismic waves through different lithological media.
The most commonly used methods include:
Geophysical soil investigation methods have been applied to numerous infrastructure projects, including sections of highways and expressways such as the Nević Polje – Turbe expressway, Tuzla – Maoča highway, and the Mostar North – Mostar South motorway.
The chairlift system is a detachable six-seater. The detachable six-seater chairlift replaced the existing three-seater chairlift. The departure station is positioned at the existing departure station of the three-seater, while the arrival station is located at the intermediate station, both of which are larger in size compared to the three-seater stations.
The detachable chairlift is a high-capacity transport system that moves passengers from one location to another with full comfort and safety. The detachable six-seater serves to transport passengers from Babin Do to Međustanica. Its technical specifications have been tailored to meet the Client’s requirements. The design and installation were carried out according to the highest safety standards worldwide.
Chairlift Specifications
The total length of the Klopče – Donja Gračanica section is 5.8 km and features several significant structures: the first part of the route includes two viaducts (Klopče, Klopačke Stijene) and one tunnel (the artificial Klopče tunnel). The second half of the section is characterized by almost no open road; instead, it alternates between a total of three viaducts (Babina Rijeka, Pehare, and Ričice) and two mountain tunnels (Ričice and Pečuj).
The main design defines the configuration of the reconstructed intersection as a single-lane roundabout with an outer radius of R = 41.00 m. The location and layout of the designed roundabout are constrained by limiting factors present at the site of the existing intersection. These constraints include the proximity of the existing “Energopetrol” gas station, appropriate geometry of the roundabout arms, as well as an existing pedestrian underpass on the “Sarajevo” arm. The subject roundabout falls into the category of medium urban and medium rural single-lane roundabouts (with an outer radius between R = 35.0 m and R = 45.0 m), with a capacity ranging from 20,000 to 22,000 vehicles per day.
The design solution includes a single-lane roundabout with a radius of 20.5 m and four arms. The width of the traffic lane is 6.5 m, and the carriageway width intended for prefabricated traversable elements is 1.0 m.
As part of the sanitary sewer project in the municipality of Tešanj, the main sanitary sewer collector was designed with a length of 4,700 meters. Its route is aligned along existing or planned roads and follows the planned Trebačka River course, allowing collected wastewater to be conveyed by gravity flow to the planned wastewater treatment facility.
In addition to the main collector, secondary sanitary sewer collectors and lower-order collectors were designed (totaling 4,000 meters) that feed into the main collector. This design effectively addresses the sewage system needs of the Karadaglije, Jablanica, Tugovići settlements, as well as other individual properties.
The project for the Tuzla-Maoča highway section includes LOT 4a (10.04 km) and LOT 4b (2.5 km) with the following components:
LOT 4a (10.04 km)
LOT 4b (2.5 km)
The engineering geological and hydrogeological investigative works along the route and structures included the following:
Measurement of horizontal soil displacements in installed inclinometer systems. Measurements were conducted using BRAIN MEMS inclinometer systems (Borehole Readout Array for Inclinometers) manufactured by SISGEO, Masate MI, Italy, with electronic data reading and analysis performed in KLION software.
Conducting geophysical surveys along the highway route using the shallow seismic refraction method to determine the quality of the soil and embankments in the subgrade.
Design&QC was engaged as the geotechnical supervision team member to ensure all geotechnical works are executed in accordance with the project technical documentation, applicable standards, and regulations.
The highway route subsection Vranduk – Ponirak is part of the Poprikuše – Zenica North (Donja Gračanica) section, which continues north to the Nemila – Vranduk subsection and south to the Ponirak – Vraca subsection. The total length of this section is 5.3 km.
A distinctive feature of the route is the horizontal and vertical separation of the left and right carriageways due to the highway running through very steep slopes. The highway is mostly built in a cut section, requiring a significant number of high retaining walls constructed using reinforced earth technology.
The contract includes expert supervision services for the construction works at the Svilaj Border Crossing. Design&QC was engaged as the main coordinator in the supervision team, responsible for overseeing geotechnical works and road/traffic-related activities.
The fixed quad chairlift was originally constructed at the Međustanica – Bjelašnica Peak location in 2017. Due to its unfavorable geographic position and strong winds reaching speeds of up to 150 km/h, as well as heavy snowfall and icing conditions, the chairlift’s operation was frequently disrupted. For this reason, the Client decided to relocate it. Since the quad chairlift at its current location could not be used at full capacity, moving it to a new site would increase the vertical transport capacity and significantly contribute to the development of the ski resort.
This project involves the vertical transport system of the quad chairlift along the ski lift BY route, with a capacity of 600 persons per hour.
The new quad chairlift location, including both old and new associated components, consists of:
By constructing/relocating the four-seater chairlift to a new location, the lift will gain greater capacity for transporting passengers/skiers on the ski slope. To facilitate easier boarding and disembarking of skiers, a conveyor belt is planned just before passenger loading, serving as a pre-acceleration system.
The project includes the construction of a new branch (Branch 2) of the existing chairlift. The newly designed chairlift features a lower drive station and an upper turnaround station, with no intermediate stations.
Branch 2 of the chairlift consists of:
The preliminary design defined the main building, which includes an operational/manipulation area, a service room with a generator, a waiting area, and an information desk. In addition to the main building, the design also specified the reception building and landscaping solutions for both structures. Based on the project brief, the chairlift was calculated and the optimal components were designed. The chairlift consists of a lower and upper station, 5 support towers and 4 passenger cabins.
The planned chairlift system is a detachable six-seater. The construction of the chairlift as part of the future ski center is intended to serve as the foundation and driving force for the development of a mountain resort. The planned chairlift is a CLD6 type with a horizontal length of 1,321.80 meters and an elevation difference of 381 meters. The chairlift consists of a departure station and an arrival station. The departure station serves as the tensioning station, while the arrival station functions as the drive station. The drive station is located at the arrival station, which is considered the standard position for the drive station. This choice also helps reduce electrical energy consumption. The project includes several components: access plateau, departure station, garage and control cabin, arrival station, control cabin and electrical room and support towers.
The contract included the preparation of a geotechnical project for securing the construction pit and reports on the engineering-geological and geomechanical characteristics of the site for the residential and commercial buildings on Midhata Karića Mitketa Street in Sarajevo. The construction pit was secured with piles of Ø800 mm diameter and active geotechnical anchors arranged in two rows, along with the construction of a reinforced concrete retaining wall and a wide excavation on the southeast side. The anchors were made of high-strength steel St 1550/1770, with steel cables 15.30 mm thick. The piles were connected with a reinforced concrete head beam, between which a reinforced concrete slab, waterproofing, and drainage concrete with D200 pipes for seepage water drainage were constructed. The northeast side was secured with piles and steel struts due to limited space, while the northwest side was executed as a wide excavation with a 1:1.5 slope.
The project involves the reconstruction of the main road over a length of 75 meters, including the implementation of an appropriate surface drainage system and the rehabilitation of the retaining structure.
The stabilization of the subject section is achieved through support elements arranged in both horizontal and vertical directions. Cable anchors are installed through the body of the existing retaining wall. These anchors are prestressed and connected to the retaining wall body via reinforced concrete buttresses. The buttresses are supported by two rows of micropiles through a connecting reinforced concrete beam.
The project included the preparation of main designs, geotechnical reports, and engineering-geological and geotechnical characteristics assessments for several locations:
The project involves securing the entrance and exit portals of Tunnel T2. To ensure the stability of steep slopes and protect the highway from potential collapse of material from the cut slope or unstable steep embankments, the structure is designed as a tunnel gallery, a roughly monolithic reinforced concrete frame construction. The galleries are subjected to horizontal forces from soil pressure, which is why the construction of piles on both sides of the gallery is planned. The piles along the slope also act as retaining walls, built first to absorb soil forces and enable the subsequent construction of the gallery.
The “Jasen” road tunnel is located on the main road M16.2 Bugojno – Jablanica, near the settlement of Ustirama, between km 57+756 and km 58+121. It was built in 1954/1955 and has a total length of 365 meters. Based on its position relative to the terrain configuration, the tunnel is classified as a hillside type.
The construction was carried out using the old Austrian method, with excavation chambers (technological working joints) measuring 6 meters each, while the tunnel lining consists of concrete blocks. However, the existing cross-section of the tunnel does not meet the requirements for the clearance profile. The Jablanica – Prozor road, built around 1960, was designed to closely follow the natural terrain configuration, allowing for significant cost reduction.
Due to concerns about the thickness of the tunnel lining and the condition of the rock mass behind it, the optimal solution chosen was to lower the tunnel profile by approximately 50 cm. This approach avoids complete removal of the existing lining and, depending on the extent of demolition, applies an appropriate underpinning system.
The drainage system covers the Babin Do plateau, including the parking area, access roads, and plateaus. The project includes a closed drainage system with treatment via an oil and light liquids separator, as well as the design of an additional concrete sedimentation tank. This is necessary because the treated water is reused for snowmaking on the ski slopes.
The expansion of the existing snowmaking system includes extending the pipeline network for snowmaking, installing inspection chambers for artificial snowmaking, and installing snow guns. The artificial snowmaking system expansion involves:
The slope rehabilitation included protection of the lower part of the slope against erosion and support of stone blocks with reinforced concrete buttresses.
The roundabout connects the streets M17/R953, Lužansko Polje, and IV Viteške Brigade. This four-leg intersection is classified as a medium-sized roundabout with an outer diameter of 50.00 meters, corresponding to an outer edge radius of 25.00 meters and an inner radius of 16.00 meters. The circulating lane on the inner radius is designed with a width of 2.00 meters, while the overall width of the circular roadway is 9.00 meters.
Traffic flow is ensured for the reference vehicle — a truck with a trailer. Pedestrian pathways are designed primarily in the same locations as existing ones, with a width of 1.60 m, except in areas where adjustments were made to connect with the existing pedestrian pathways, resulting in slightly narrower or more frequently wider sections. The geometric design elements of the intersection arms have been optimized to match the existing alignment, both horizontally and vertically.
The main design includes the reconstruction of the intersection, adopting a modified single-lane roundabout configuration. The solution consists of two circular segments with an outer diameter of 33 m, each featuring a 6 m wide carriageway and a 1.50 m wide traversable strip. These segments are interconnected by a continuous 6 m wide roadway.
Within Mission G31, the rehabilitation project for the right side of the Treševine cut was developed. To ensure effective landslide rehabilitation, certain securing measures were implemented. The proposed solution included a design using shotcrete and anchors, securing both the rock wedge and the lower part of the slope above the rock wedge.
The project included a modification of the main design for the motorway section from station km 6+500 to km 8+540, including the Medakovo interchange, the access road to the Traffic Control and Maintenance Center (COKP), the Čostovići overpass, the Medakovo overpass, the PP5 underpass, the bridge over the regulated Tešanjka River bed, the hydraulic structure HO8, retaining structures, reinforced earth structures, slope stabilization, internal and external drainage along the alignment and on structures, and the regulation of the Tešanjka River.
The modification of the main design for the motorway section from station km 1+120 to km 2+040 included the Usora interchange, the R2 roundabout, and the Kraševo roundabout on the realigned main road M4.
Underpass PP5 and bridge on the access road to COKP (as-built condition)
The project included a modification of the main design for the motorway section from station km 6+500 to km 8+540, including the Medakovo interchange, the access road to the Traffic Control and Maintenance Center (COKP), the Čostovići overpass, the Medakovo overpass, the PP5 underpass, the bridge over the regulated Tešanjka River bed, the hydraulic structure HO8, retaining structures, reinforced earth structures, slope stabilization, internal and external drainage along the alignment and on structures, and the regulation of the Tešanjka River.
The modification of the main design for the motorway section from station km 1+120 to km 2+040 included the Usora interchange, the R2 roundabout, and the Kraševo roundabout on the realigned main road M4.
MEDAKOVO OVERPASS (As-Built Condition and Design Solution)
The project included a modification of the main design for the motorway section from station km 6+500 to km 8+540, including the Medakovo interchange, the access road to the Traffic Control and Maintenance Center (COKP), the Čostovići overpass, the Medakovo overpass, the PP5 underpass, the bridge over the regulated Tešanjka River bed, the hydraulic structure HO8, retaining structures, reinforced earth structures, slope stabilization, internal and external drainage along the alignment and on structures, and the regulation of the Tešanjka River.
The modification of the main design for the motorway section from station km 1+120 to km 2+040 included the Usora interchange, the R2 roundabout, and the Kraševo roundabout on the realigned main road M4.
Čostovići Bridge (As-Built Condition and Design Solution)
The length of LOT 1, Tarčin – entrance to the Ivan Tunnel, is 4.9 km. This subsection starts at the end of the Lepenica – Tarčin section, immediately after the Tarčin interchange. In the initial part of this motorway alignment, from the tie-in point with the preceding section to the beginning of bridge M1 – Raštelica 1 (L = 518 m), over a length of approximately 1,200 m, the alignment is situated on high embankments constructed with reinforced earth structures.
After this sector, the alignment crosses to the opposite slope via the Raštelica 1 bridge. The bridge spans over the main road M17 and the Kalašnica River. It consists of 13 spans. Due to spatial constraints, a Type 1 rest area (rest stop without service facilities) is planned. Following the left-side rest area, the alignment continues over bridge M2 – Raštelica 2 (L = 589 m), which spans the main road and a wider valley, and therefore comprises 19 spans. The right-side rest area, along with the entry and exit ramps, is located from approximately the beginning of bridge M2 up to the entrance to the Ivan Tunnel.
The company Design&QC d.o.o. Sarajevo, as a member of the consortium, was responsible for preparing the following phases of the design documentation:
The project includes a twin-tube tunnel:
The length of the main tunnel tube is 5,557.28 meters (this includes the lengths of the entrance and exit galleries),
The length of the service tunnel tube is 5,521.98 meters (including the length of the exit gallery).
Section Svilaj – Odžak from km 10+020 to km 10+762.5, including the access road to the main road M14.1. The project includes the Odžak interchange (trumpet-type junction), an access road approximately 4.1 km long, as well as the connection to the main road M14.1 with a roundabout.
The preparation (amendment) of the conceptual and main design for the Orašje–Tuzla motorway, section Tuzla–Maoča (LOT 4, connection with LOT 3 – Čanići), includes:
This contract includes the preparation of all phases of the main design for the route and structures of the Nević Polje – Travnik – Turbe expressway (length 12.5 km). This section is part of the planned Lašva – Nević Polje – Jajce expressway. The planned expressway will connect central Bosnia and Herzegovina with the highway on Corridor 5c near the Lučani (Lašva) interchange, representing the most important traffic route for the Federation of Bosnia and Herzegovina in the west-east direction. This section is part of the TEN-T Core Network international route E-761 (Bihać – B. Petrovac – Jajce) and the setto network section 2a Okučani (Republic of Croatia) – Banja Luka – Travnik – Lašva. The construction of this new “expressway” class road will significantly improve traffic conditions along the Sarajevo – Banja Luka corridor.
Design&QC d.o.o. Sarajevo, as a member of the consortium, was responsible for preparing the following project documentation phases:
TURBE BRIDGE (3D structural model and longitudinal profile)
The project involved the preparation of the main design for the connecting road of the temporary junction of the M17 main road to the Corridor Vc, including a temporary side toll station (STS) in the wider area of Bradina settlement. This project is actually a modification of the existing main design prepared in July 2018. The reason for the modification is the request from the Client, JP Autoceste FBiH, for the expansion of the temporary side toll station. The previous main design planned 4 lanes (2 entrances and 2 exits) for the STS, while this project foresees 6 lanes (3 entrances and 3 exits). Additionally, this project includes corrections at the very beginning of the connecting road due to changes from the detailed design of the roundabout, which actually represents the connection with the existing M17 main road.
This unit provides professional and technical supervision services during construction works, ensuring that all work is carried out in accordance with project designs, legal regulations and technical standards.
This organizational unit provides expert services in the fields of engineering geology and hydrogeology, including investigative works, geophysical and other in situ tests necessary for the preparation of geomechanical reports, geological risk analysis, terrain stability assessment, as well as safe and efficient planning of construction projects. Hydrogeological activities include detailed groundwater investigations and the preparation of hydrogeological studies and reports, which serve as the basis for sustainable water resource management.
GEOLOGY / HYDROGEOLOGY includes:
This organizational unit is engaged in the development of design solutions in the field of:
The organizational unit for geotechnical analysis and design solutions focuses on:
This organizational unit is engaged in the design of various types of engineering structures, such as:
This organizational unit focuses on the design of transportation infrastructure of various categories, including:
The work is centered on designing traffic solutions in accordance with technical standards, emphasizing functionality, safety and durability.
