Excavation Progress — 86 Percent Complete

As of the most recent verified reports, excavation at The Mukaab site in the al-Qirawan district of northwest Riyadh has reached 86 percent completion. Over 10 million cubic meters of earth have been moved from the construction site as part of a total excavation scope encompassing 40 million cubic meters of material. This earthmoving operation ranks among the largest in global construction history, comparable in volume to major civil engineering projects such as dam construction and canal expansion programs. The Panama Canal expansion, completed in 2016, involved approximately 150 million cubic meters of excavation over a decade. The Mukaab’s 40 million cubic meters, concentrated within a single urban construction site rather than spread across a 77-kilometer canal corridor, represents an excavation intensity per unit area that is exceptionally high by global standards.

Excavation Scope and Purpose

The 40-million-cubic-meter excavation creates the below-grade volume required for the Mukaab’s foundation system, underground parking, service infrastructure, and connection to the broader New Murabba underground transit network. The depth of excavation varies across the site, with the deepest cuts occurring beneath the Mukaab’s 1,200-pile foundation and the shallowest at the site periphery where grade transitions connect to surrounding neighborhoods.

The below-grade infrastructure is itself substantial. Underground parking for a structure designed to attract 90 million annual visitors plus accommodate thousands of residents requires capacity for tens of thousands of vehicles. Service infrastructure — mechanical rooms, electrical substations, water storage, sewage pumping, fire suppression systems, and the plant rooms for the AI-powered climate control that will manage 64 million cubic meters of enclosed space — demands dedicated below-grade floors with generous ceiling heights and heavy floor loading capacity. Underground transit connections must align with the autonomous transportation network planned for the development, requiring precise horizontal and vertical alignment with future tunnel boring routes.

The excavation also prepares the ground for the world’s largest raft foundation — the massive concrete slab that will distribute the Mukaab’s weight across the 1,200 piles driven into bedrock. The raft foundation requires an excavation profile that provides a level, stable surface at the correct elevation, with adequate working space around the perimeter for formwork, waterproofing, and drainage installations.

Geological Conditions at the Al-Qirawan Site

The al-Qirawan district’s geotechnical conditions include surface layers of windblown sand, intermediate cemented soil formations, and deeper rock substrates. The excavation has progressed through these layers sequentially, with different earth-moving equipment deployed for each soil type. Sandy surface layers yield to conventional excavators and loaders, while cemented and rock layers may require hydraulic breakers or controlled blasting.

The windblown Aeolian sand that forms the surface layers is characteristic of the central Arabian Peninsula. This unconsolidated material is easily excavated but presents challenges in excavation wall stability — unsupported sand slopes tend to slump, requiring either shallow cut angles or temporary shoring to prevent collapse into the working area. In a 400-meter-square excavation, the volume of additional material that must be removed to maintain stable cut slopes can be significant, adding to the total excavation volume.

Below the sand, the cemented sarooj formations present variable excavation difficulty. Where cementation is weak, conventional excavators can break through the material directly. Where the sarooj is heavily indurated — approaching the hardness of weak rock — hydraulic breakers mounted on excavators are required. The boundary between these conditions is not uniform across the site, meaning that excavation equipment must be adaptable to changing conditions encountered during production.

At depth, the limestone and sandstone bedrock of the Arabian Shield provides the stable foundation stratum into which the Mukaab’s piles are anchored. Excavation into rock formations typically requires controlled blasting or rock sawing techniques, applied carefully to avoid disturbing the integrity of the rock mass that must support the pile loads. The transition from soil to rock excavation typically reduces production rates significantly — a factor that may influence the rate at which the remaining 14 percent of excavation is completed.

Equipment and Methodology

The scale of the Mukaab excavation demands a fleet of earth-moving equipment operating continuously across the site. Large hydraulic excavators — machines with bucket capacities of 5 to 10 cubic meters and operating weights exceeding 100 tonnes — serve as the primary excavation tools. These machines load articulated dump trucks that transport material to processing and staging areas, either directly within the site boundary or across the temporary bridge spanning King Khalid Road.

The excavation methodology follows a top-down sequence, removing material in horizontal benches that gradually lower the site to the required depth. Each bench is typically 3 to 5 meters in height, providing stable working platforms for equipment operation while maintaining adequate wall stability between lifts. In areas requiring deep excavation, the number of sequential benches may reach 10 or more, with each bench requiring its own access ramps, drainage provisions, and safety setbacks from the excavation face.

Water management during excavation, while less challenging in Riyadh’s arid climate than in many global construction locations, remains a consideration. Seasonal rainfall, though infrequent, can deliver substantial volumes in short periods, requiring pumping systems to dewater the excavation and prevent standing water from destabilizing soil faces or interfering with equipment operations. Groundwater levels in the al-Qirawan area, while generally deep, may be encountered in certain zones and require localized dewatering.

Material Repurposing

All excavated material is being repurposed rather than disposed of in landfill, aligning with the project’s sustainability commitments. Uses include fill material for site grading within the broader New Murabba development, aggregate for concrete production serving the project’s enormous concrete demand, and landscape fill for the 25 percent green space allocation across the 19-square-kilometer development. The zero-landfill approach eliminates what would otherwise amount to approximately 2 million dump truck loads of material to external disposal sites — a reduction that has concrete environmental, traffic, and cost benefits for both the project and the surrounding Riyadh community.

Material classification and sorting occur at the point of excavation or at designated processing areas within the site. Sand, sarooj, and rock are directed to different stockpile locations based on their intended end use. Rock material destined for concrete aggregate passes through crushing and screening plants that produce the gradation specifications required for structural concrete. Fill material is transported directly to areas requiring grade adjustments, where it is placed in controlled lifts and compacted to engineering specifications.

Excavation Timeline and Production Rate

Excavation began following the project’s February 2023 announcement. The progression from 0 to 86 percent completion over approximately 30 months represents an average daily earthmoving rate of approximately 37,000 cubic meters — equivalent to filling roughly 15 Olympic swimming pools every day. This rate places the Mukaab excavation among the highest sustained production rates achieved in urban construction globally.

Achieving the remaining 14 percent would require moving approximately 5.6 million additional cubic meters of material. At the historical average production rate, this volume could be completed in approximately five to six months. However, the remaining excavation may involve proportionally more rock and cemented formation, which produces at lower daily rates than the sand and loose soil that dominated earlier phases. A conservative estimate might extend the completion timeline to six to eight months from the last reported progress date.

Significance of the 86 Percent Milestone

The excavation milestone carries additional significance because it represents the construction activity that has continued despite the January 2026 suspension of other Mukaab construction activities. The suspension applies to work “beyond soil excavation and pilings,” meaning that foundation preparation continues while the building’s superstructure plans are under review. This exemption reflects the critical-path nature of foundation operations — the world’s largest raft foundation cannot be constructed until excavation reaches final grade, and the 1 million tonnes of structural steel cannot be erected until the raft foundation is complete.

The decision to continue excavation during the suspension also reflects practical construction logic. Demobilizing and remobilizing a large earthmoving fleet — with dozens of excavators, hundreds of trucks, and thousands of support personnel — carries significant cost and schedule penalties. Maintaining continuous excavation operations through the suspension period avoids these penalties and ensures that the foundation work is ready for the next construction phase whenever the feasibility review concludes.

The contractor ecosystem managing the excavation operates under Bechtel’s overall project management coordination. While HSSG Foundation Contracting executes the piling operations that follow in the wake of completed excavation areas, the earthmoving contractors must coordinate their production with the piling schedule to ensure that excavated areas are available for pile installation on a just-in-time basis. This coordination is managed through the phased delivery strategy that sequences construction activities across the site.

Safety Management During Deep Excavation

The deep excavation at the Mukaab site introduces safety hazards that scale with the depth and area of the cut. Bench edge stability is the primary geotechnical safety concern — the terraced excavation walls must maintain structural integrity throughout the excavation period, which extends across multiple seasons including Riyadh’s infrequent but intense rainfall events. A bench failure in an active excavation zone can bury equipment and endanger workers, making continuous slope monitoring an essential safety practice.

Geotechnical monitoring instrumentation — including inclinometers measuring lateral ground movement, piezometers tracking groundwater pressure, and survey prisms detecting surface displacement — provides early warning of slope instability. This instrumentation network feeds data to the geotechnical engineering team in real time, enabling precautionary evacuation of work zones before any failure occurs. The monitoring density increases near the deepest excavation areas and in zones where geological conditions show higher variability, with readings taken daily or more frequently during periods of elevated risk such as after rainfall events.

Vehicle and equipment operations within the excavation present fall-from-height risks at bench edges. Articulated dump trucks operating on narrow bench roads above deep drops must follow strict traffic management protocols: one-way traffic on single-lane sections, speed limits of 15 kilometers per hour on internal haul roads, mandatory reversing cameras and proximity sensors on all vehicles, and physical stop blocks at bench edges where trucks must approach the edge for loading or tipping operations. Equipment operators receive site-specific induction training covering the excavation layout, emergency exit routes from below-grade work areas, and the location of rescue equipment staged at key points throughout the excavation.

Dust suppression is both an environmental and a safety requirement. The excavation of dry desert soils generates airborne particulate matter that reduces visibility for equipment operators, degrades air quality for workers, and drifts beyond the site boundary into adjacent residential neighborhoods. Water tankers equipped with spray bars make continuous circuits of active haul roads and excavation faces, suppressing dust at its source. During periods of high wind — common in the open terrain of northwest Riyadh — dust suppression efforts intensify, and excavation operations may be temporarily suspended if visibility drops below safe operating thresholds.

Coordination with Piling Operations

The excavation program and the piling operations executed by HSSG Foundation Contracting operate in a carefully choreographed sequence across the 400-meter-square site. Piling cannot begin in any zone until excavation has reached the required founding level — the elevation at which pile drilling commences. Conversely, the piling rigs require access across completed excavation areas, meaning that excavation sequencing must account for the movement paths and working radii of the piling equipment.

This coordination is managed through a zonal approach: the site is divided into work zones, each progressing through a defined sequence of excavation, pile installation, pile testing, and preparation for raft foundation construction. The excavation team advances through a zone, achieves the specified depth, and hands it over to the piling team. The piling team installs and tests piles within that zone while the excavation team advances into the next zone. This rolling-wave approach maximizes the utilization of both the earthmoving fleet and the piling rigs, avoiding the idle time that would occur if one operation had to fully complete before the other could start.

The remaining 14 percent of excavation — approximately 5.6 million cubic meters — must be coordinated with the final 200 piles in HSSG’s program. The completion sequencing of these two operations determines when the site is ready for raft foundation construction, which in turn sets the earliest possible date for structural steel erection. Every day of delay in completing excavation and piling cascades through the entire construction schedule, making the coordination between earthmoving and foundation contractors a critical-path management priority for Bechtel’s project management team.

For independent reporting on excavation progress, see Construction Week Online and Interesting Engineering, both of which have published verified coverage of the Mukaab’s earthworks milestones.

Excavation Progress — 86 Percent Complete