Sphere Ark Project

This technical regulation represents a comprehensive engineering solution for the construction of an autonomous underground structure of increased strength, adapted to specific hydrogeological conditions. The project takes into account the deep occurrence of groundwater (10–12 meters) and the potential landslide activity of the slope, ensuring absolute safety during the lifetime of the owner and guaranteed conservation of the object on a scale of eternity.

Stage 1: Stabilization of the existing building (Creation of the exoskeleton)

Before starting heavy excavation work, it is necessary to fix the old above-ground house, which already has deformation cracks from the movement of surface layers of clay.

• Angle pressure distributors:A hot-rolled steel corner measuring at least 100x100x8 mm is mounted vertically from the foundation to the roof at all four corners of the building. Installation is carried out using fresh cement-sand mortar M300 for tight adherence to the brickwork, followed by tightening with chemical anchors.
• Horizontal continuous belts:At the foundation level, the interfloor ceiling, and the base of the roof, the building is girdled with a channel 20P. The corners are welded into a rigid spatial structure. The channel receives the arch thrust and uneven sediment, distributing the load over the entire plane of the walls.
• Foundation strengthening:Along the perimeter of the existing foundation, a monolithic reinforced concrete collar with a width of 400 mm is poured to the depth of base clay. High-strength reinforcement A500C is tied into the existing foundation through drilled chemical anchors.

Stage 2: Soil excavation and construction of temporary retaining structures

• Excavation geometry:Directly next to the reinforced building, a pit is excavated with a depth of 7 meters. The slope of the pit walls is made at an angle of 45° to prevent sudden collapse of wet clay.
• Shotcrete protection:Immediately after excavating each meter of soil depth, the pit slopes are covered with a layer of shotcrete 50 mm thick over a steel mesh 100x100x4 mm with anchoring into clay to a depth of 1.5 meters.
• Dredging of base clay:At the bottom of the pit, a horizontal hard clay lens is opened, which serves as a natural waterproof floor and ideal base for a spherical shell.

Stage 3: Monolithic spherical shell (Class B100 concrete)

The core of the structure is an ideal sphere with an outer diameter of 6 meters. The wall thickness is 700 mm and consists of two monolithic layers. The outer layer is structural hydrophobic armor-piercing concrete, the inner layer is thermal insulation.

Technological map of concrete mixture class B100 (per 1 m³ of ready-made concrete):

• Binder:Portland cement without additives PC I-500N – 550 kg.
• Filler 1 (Large):Washed granite crushed stone of a cube-shaped fraction 5–10 mm (extra-strong rocks, compressive strength of at least 1400 kgf/cm²) – 1050 kg.
• Filler 2 (Fine):Enriched quartz sand, fineness modulus Mk = 2.4–2.6 (completely cleared of silt and clay inclusions) – 650 kg.
• Active mineral supplement:Condensed microsilica (fractionated ultrafine material for compacting the structure of concrete) – 60 kg.
• Plasticizer:New generation polycarboxylate superplasticizer (ensures the mobility of the P5 mixture with a minimum water-cement ratio W/C = 0.26–0.28) – 6.5 kg.
• Integral waterproofing:Penetrating additive Penetron Admix (introduced at the mixing stage, provides an eternal effect of self-healing of microcracks up to 0.4 mm wide due to the growth of crystals upon contact with water molecules) – 4 kg.
• Mixing water:Purified, without chemical impurities – 150 liters.

Reinforcement and filling scheme:

The internal supporting frame is knitted from heavy steel reinforcement class A500C with a diameter of 22–25 mm with a cell pitch of 150×150 mm. Critical parameter: the design protective layer of concrete from the outer edge of the sphere to the steel reinforcement should be exactly 400 mm. With an external armor thickness of 500 mm, the steel is completely inaccessible to oxygen and moisture, which prevents corrosion for hundreds of thousands of years.

The inner layer, 200 mm thick, is applied by spraying or pouring into permanent formwork. Used perlite concrete (cement mortar filled with expanded perlite sand), which provides a thermal conductivity coefficient λ ≈ 0.12 W/(m °C) and eliminates the “cold basement” effect.

Stage 4: Communication gateways and preservation nodes

• Horizontal entrance gate:Access to the sphere is made horizontally through the bottom of the slope. The interface between the entrance tunnel and the sphere is carried out according to the principle telescopic expansion joint (“a glass in a glass”). The outer shaft has a larger diameter and fits freely onto the monolithic neck of the sphere. The joint is sealed with a massive corrugated cuff made of ethylene-propylene rubber (EPDM). During micro-shears of the soil, the shaft slides along the neck without transferring breaking stress to the sphere.
• Gravity sewerage:An outlet pipe with a diameter of 110 mm is laid from the lower third of the sphere with a slope of 2% (2 cm per 1 meter) directly into the septic tank located below the slope. The penetration through the wall of the sphere is realized through a conical titanium sleeve. The gap between the plastic pipe and the titanium body is tightly stamped with rings made of dry pressed sodium bentonite. When the soil layers shift, the plastic pipe is cut along the plane of the wall. The erupting moisture instantly activates the bentonite: it increases in volume up to 16 times, turning into a dense waterproof clay gel, tightly sealing the 110 mm hole.
• Ventilation capillaries:The classic wide ventilation pipes are replaced by a bundle of 5–7 zigzag titanium tubes of small diameter (8–10 mm). This geometry completely eliminates the weakening of the protective properties of B100 concrete. The system is equipped with a mechanical rotary valve with a heavy eccentric pendulum pin. When the spatial position of the sphere changes (tilt, rotate), gravity automatically pulls the pin and seals the ventilation circuit tightly.

Stage 5: Lighting, biological comfort and biological protection

• Passive insolation circuit (“Western trap”): An optical shaft protected by armored quartz glass is brought to the surface of the hill. A system of passive mirrors is mounted inside, oriented strictly towards the western point of the horizon. The light flux is collected and transmitted into the sphere through a flexible fiber-optic cable of large cross-section (light guide), ending in a ceiling diffuser. The system catches the tangential rays of the setting sun, extending the natural daylight hours inside the capsule by 1.5 hours compared to the surface.
• Photoluminescent “Quantum Dome”: The roof of the residential area is covered with a composition based on a coarse-grained (150 microns) moisture-resistant phosphor – strontium aluminate ($SrAl_2O_4:Eu,Dy$). Liquid potassium glass is used as a binder. The composition is applied to perlite concrete, forming a single silicate matrix. During the day, the dome accumulates energy from the solar spectrum from the light guide. After sunset, a deep moon-white glow (wavelength ~520 nm) is activated, providing soft passive illumination for 3-4 hours without consuming electricity. The crystal lattice of strontium aluminate is stable and does not degrade for centuries.
• Thermo-mouse barrier: Before backfilling the soil, the frontal (extending to the surface) part of the sphere and the entrance gateway are lined with slabs of foam glass (Foamglas) 150 mm thick. This material has zero water absorption, durability of glass and completely eliminates damage by rodents. Mice are physically unable to chew through porous silicate glass, which protects the thermal circuit from creating holes. Foam glass shifts the freezing point outward, completely eliminating the risk of ice forming in the adjacent clay.

Final integration: Ground “Umbrella House”

Directly above the underground structure, a classic residential building is being erected, the foundation of which is an insulated Swedish slab (USP) with a wide warm blind area (2 meters around the perimeter). The ground loop performs three important functions:

1. Heat Shield: Constant heating of the above-ground house and thermal insulation of the USP completely eliminate freezing of the soil above the sphere. The clay around the entrance group is in a stable temperature range all year round (+8…+12°C), which reduces the residual effects of frost heaving to absolute zero.
2. Engineering vestibule: The entrance to the underground sphere begins from the dry, heated area of the above-ground house through a secret vertical or inclined hatch. All noisy technical equipment (well filters, cleaning systems, stabilizers) is removed to a surface outbuilding.
3. Visual camouflage: From the outside, the object looks like a standard country cottage, completely hiding an autonomous strategic-class bunker underneath.

In the event of a large-scale geological cataclysm (a deep landslide of Mount Tsetsino thousands of years later), the light ground house is destroyed, freeing the sphere. The ideally round shape of B100 concrete without corners or protrusions allows the capsule to smoothly slide and rotate through the thickness of the clay masses. All communications are cleanly cut off along the breakdown lines, bentonite and pendulum seals seal the entrances, and the Ark goes into autonomous underground navigation, keeping the internal ecosystem absolutely intact.