Generative Sandscape_Siwa Oasis New Habitat

Generative Sandscape S i w a

O a s i s

N e w

Hossam Badr Thesis Supervisor: Prof. Dr. Sina Mostafavi Second Supervisor: Prof. Dr. Manuel Kretzer

H a b i t a t

2

3

Declaration

I declare that this thesis is my own original work and all the sources of materials used for this thesis have been fully acknowledged. This document has not been previously submitted, in entirety or in part, to obtain academic qualifications in any other university.

Place, Date Signature

4

Acknowledgments

First of all, I would like to thank ALLAH for his generosity, blessings and giving me power, health and patience to finish this piece of work.

Now, I would like to thank and express my deep and sincere gratitude to my supervisor Prof Dr. Sina Mostafavi and Manuell Kretzer for their invaluable assistance in producing the hall thesis.

Special thanks goes to the life friends and the journey colleagues Amr Hamead and Mohamed Mansour for their endless help and support, and Manuel Ragheb for language check.

I would like to extend thanks to my colleagues and friends for discussions, suggestions and criticism: Ahmed Hesham, Ahmed Eleshafi, Hosam Hesham, Kamal Amged, Mohamed Waseem, Maged Elbanna,Yaseen Jabr, Mohammed hegaz, Adib Khaeez and valmir xh kastrati.

Finally, but by no means least, I owe everything to my family who encouraged and helped me at every stage of my personal and academic life and longed to see this achievement come true. They are the most important people in my world and I dedicate this thesis to them and to Shereen the love of my life.

5

Table of Contents

1

Introduction

3

3.1 The Invisible Flight Patterns of Birds 3.2 Sand Travel Diagram ”STD” 3.2.1 ”STD” in 2D 3.2.2 ”STD” in 3D 3.3 Site Analysis 3.3.1 Topography 3.3.2 Particles Simulation 3.4 Topology Deformation 3.4.1Carved 3.4.2Build up 3.5 Site Profile

1.1 Keywords 1.2 Abstract 1.3 Introduction 1.4 Background 1.4.1 Design objective 1.4.2 Design methods 1.5 Case studies 1.5.1 Computational 1.5.2 Architectural 1.6 Iterative Design Process

2

Site 2.1 New Cairo Urban study 2.2 Site Siwa oasis /Historical + Cultural background 2.3 Case Study 2.3.1Traditional Desert Buildings in Siwa Oasis 2.3.2 Adrere amellal indigenous eco hotel 2.4 Siwa Urban Growth 2.5 Sand Life cycle

6

Design Research

4

Urban Proposal (Macro) 4.1 Site Profile 4.2 Iterative Design Process 4.3 Simulation 4.3.1 Sand-travel Diagram 4.3.2 Dune-field Simulator 4.4 Results 4.5 Zone1 (Erosion) 4.6 Urban Proposal 4.6.1 Iterative Designs 4.6.2 Final Proposal

5

Design Proposal (Meso)

7

Conclusion

5.1 Iterative Design Process Zone 2 5.2 Zone 2 (Sand Shifting) 5.3 Design objective 5.4 Form finding 5.4.1 Project Program Optimization 5.4.2 Structural Optimization 5.4.3 Wind Pressure Simulation 5.5 Drawings 5.5.1 Exploded Axonometric 5.5.2 Plans 5.5.3 Sections 5.6 Renders 5.7 Micro to Urban

6

Materiality & Fabrication (Micro)

References

6.1 Materials 6.1.1 Sand solidification technology (SST) 6.1.2 Sand stone 6.2 Building Layers Materials 6.3 Siwa Robot 6.4 Building Layers Materials 6.5 Printing Time 6.6 Multi Scale Design

7

Work Frame

Site

Thesis Project

Research

Architecture Project

8

Robotic Research

Materials

Case Studies

Project program

Robotic Production

Conclusion

Micro

Meso

Macro

9

1

Introduction 1.1 Keywords 1.2 Abstract 1.3 Introduction 1.4 Background 1.4.1 Design objective 1.4.2 Design methods 1.5 Case studies 1.5.1 Computational 1.5.2 Architectural 1.6 Iterative Design Process

10

11

1

Abstract

The research discuses building new communities in the desert. Siwa oasis in Egypt was selected as the project location because of its historical background and how the Siwa inhabitants adapted with desert using local material to build efficient architecture. Building in the desert has many challenges (environmental, physical and philosophical). As the main cause for desertification is sand shifting, the research focuses on studying the behaviour of sand shifting to use it as potential for building with sand as building material.

The design approach is to learn from the process through which the nature is formed through millions of years by studying the cycle of erosion and sand shifting.

The process involves diving deep into the level of particles that have been moved away by the action of natural geological agents such as flowing water, blowing winds and falling under the influence of gravity.

The Proposal to be presented here is a different way of rethink the Egyptian desert communities building methods and the materials used for construction. A huge part of the construction systems today still relies on traditional manufacturing techniques and methods of implementation. New alternatives can contribute to a new way of creating architecture in way more effective a manner. Rethinking the approach to varying structuring methods is of paramount importance in our time. Recently, computing devices have proven an increasing power in allowing for a digital fabrication approach that has out-ranged our possibility of traditional physical fabrication.

12

13

1

Introduction

Key words: Dune - Arenaceous - Desertification – Sand - Solidification -3D Printing – Erosion – Sandstone - Making Microbes - Tafoni – Egypt -Desert – Siwa - Oasis – Reclamation – Rehabilitation – Bacilluspasteurii bacteria “There are 800 million people from the poor of the third world doomed to an early death because of poor housing. These are my customers” [Fathy,1995].

Hassan fathy’s philosophy and ideas were suitable for technology and resources found in his environment and his time. He used mud as building material in his architecture such as Al-Gourna. Recently if we want to apply Fathy’s philosophy and Ideas in building new communities in the desert, Sand could be the main building material. But, how can we use sand to build? ”A single grain of sand is almost nothing” [Balmond,2002].

Of course building in the desert has many obstacles. These obstacles are environmental, physical and philosophical. Sand shifting is considered the main cause for desertification. To understand how desertification happens we must know more about sand dunes and Sand movement patterns. There are traditional anti-desertification methods that have been used in Egypt. However, with that size of development, implementation would be hard. All these obstacles must be overcome using environmental, economical solutions, with available materials and technologies.

14

15

1

Introduction

‘‘Nothing is built on stone; all is built on sand, but we must build as if the sand were stone’’ (Borges,1974).

Sand in its normal form cannot be used to build a structure but if it solidifies, it can be used in many architecture fields. One billion grains of sand comes into existence around the world every second. It’s a cyclic process: as rocks and mountains die, grains of sand are born. These grains may then become naturally glued together, or lithified (from lithos, greek for ‘stone’ or ‘rock’), into a clastic sedimentary rock, a sandstone. When that sandstone is weathered, new grains break free. In a way, the static stone mountain becomes a moving mountain of sand. Typically, the landscape of a mountain range will be lowered by a few millimetres every year [Welland 2009]. The desert sand crementation is achieved through microbially induced carbonate precipitation (MICP) using the micro-organism Bacillus pasteurii, an aerobic bacterium pervasive in natural soil deposits [Le Metayer-Levrel et al. 1999; Nemati and Voordouw 2003; DeJong et al. 2006; Whiffin et al. 2007].

This technology could be applied in many ways - as it is going to be discussed- to make sand a solid building material (Sandstone) or to stabilize sand dunes to make a privilege out of them instead of being obstacles.

16

17

1

Design objective

The objective of this paper is to explore generative design methods and developing design by simulation work-flows that consider natural behaviour of sand and robotic additive manufacturing constraints and potentials.

18

Sandstone

Sand dunes

Stones hills

Sand

19

1

Design methods

There are many reasons that make the Egyptian government choose to build large cities and communities in the desert such as: housing crisis, desertification, and the desire to maintain the fertile land around the Nile Delta. Housing crisis results from lack of planning, desert crawling over agricultural lands, and overpopulation which results in a pressure on services, especially that over a100 million Egyptians live on only about 7% of the land. All of the mentioned above causes agricultural lands to shrink.

The Proposal to be presented here is a different way of rethinking the Egyptian desert communities building methods and the materials used for construction. A huge part of the construction systems today still relies on traditional manufacturing techniques and methods of implementation. New alternatives can contribute to a new way of creating architecture in way more effective a manner. Rethinking the approach to varying structuring methods is of paramount importance in our time. Recently, computing devices have proven an increasing power in allowing for a digital fabrication approach that has out-ranged our possibility of traditional physical fabrication.

3D printing technology primary target is to print on-demand custom objects. This could be applied in arid areas, where the lack of available resources and human subsistence are a problem. The biggest problem in arid areas is not in the manufacturing tool but rather in the suitable construction systems. 3D printing robots can create architecture in the desert prior to having the desert occupied by inhabitants through an automated process that uses local materials.

20

The printing robots used are quite energy efficient when it comes to the energy consumption rates for the operation process of the robots, their monitoring and their on-site deployment. Moreover, the printers make use of solar energy on timely basis to operate. The printers perform as efficiently on implementing complex structures as they do for relatively less complex structures.

As an application for the Sand Solidifying Technology (SST), and during the construction process of new desert habitats, the printers make use of pre-considered facts regarding the wind speed, sand shifting speed rates and materials properties.

21

1

Case studies /Computational Solar Sintering

The difference between laser sintering is that it involves the uses of sun power to create 3D printed structure. A bed of sand is laid down in a tank and a Fresnel lens focus the sunlight into a point on the surface of the sand to fuse it. The system is using a cam-guided system to cut or fuse material like sand, in layers. The end layers is a 3D printed glass object mad multiple layers. As the printer works with solar energy both for its operation and for material fusion, and at the same time the materials are found locally, the technique can be considered a high sustainable one and optimal for creating customized tools and pots out of the local material [ Potra, ,2013]

22

Stone Spray

A research project by anna kulik, inder shergill and petr novikov, under the supervision of marta male alemany, jordi portell and miquel lloveras of IAAC, ‘stone spray‘ is a robotic 3D printer that produces architecture out of soil. the team’s research was focused on the field of additive manufacturing in architecture, finding means of proposing new eco-friendly, efficient and innovative systems to print architecture in 3D. the mechanized device collects dirt/sand on site and then sprays it from a nozzle in combination with a binder component. when this mixture hits the surface it solidifies to create sculptural forms. because the movements of the robot are digitally controlled by computer, the designer has direct input on the resulting shape. unlike other 3D printers, the ‘stone spray’ robot can print multi-directionally, even on vertical surfaces [Kulik,2012]

23

1

Case studies /Architectural Dune arenaceous

Architect Magnus Larsson’s proposal of a 6,000-kilometer-long inhabitable green sandstone wall along the saharan desert. The structure will be built with the help of bacillus pasteurii, a bacterial micro-organism abundantly available in marshes and wetlands. The loose sand will be transformed into a fibrous porous structure that will sustainably control desertification while housing thousands of refugees. the crux of the project however lies in the natural microbial reaction of the bacteria with the sand particles that turn them into organic dunes of structurally-sound sandstone[Larsson,2010]

24

Terri-form

The aim of the research is to address the problem of material waste and cycle of production and consumption of architecture based on the assumption that it is a product that has a certain finite life -span. Following Frei otto’s form finding experiments and based on the study of sand self-distribution behaviour acting under the force of gravity. Terri-form exploits phase transition properties of material in order to generate site fabricated architecture with a designed life-cycle in allocation where sea and desert merge.

25

1

Iterative Design Process

Feedback Meso Feedback Micro

Wind Simulation Topography analysis

Macro

Results

Feedback Micro

Wind Flow,Sand dunes field,sand particles and Drainage water simulation

Meso

Structure and wind pressure simulation

Micro

Archidynamics 26

Octopus

Bison

Results

Results

BlueCFD

Mosquito

Design Proposal

Evaluate

Design output

Feedback

Rhino v6

Grasshopper

Dunefield Simulator 27

2

Site 2.1 New Cairo Urban study 2.2 Site Siwa oasis /Historical + Cultural background 2.3 Case Study 2.3.1Traditional Desert Buildings in Siwa Oasis 2.3.2 Adrere amellal indigenous eco hotel 2.4 Siwa Urban Growth 2.5 Sand Life cycle

28

29

2

New Cairo Urban Failure New Cairo drainage problems

SOM new capital Cairo design proposal

Rains of Cairo on Egypt’s Most Prestigious Neighborhood

This photo was captured shortly after an unstable weather condition (90 minutes of heavy rain), the majority of Cairo’s streets were turned into puddles, with people stuck on the ring road for more than eight hours; which reveals the poor infrastructure conditions.

New Cairo residents, in particular, suffered the most from the side effects of the rain, with their homes, garages and cars soaked in rainwater and further leading to electricity outages in what was viewed as a governmental shortcoming, as New Cairo is relatively a new area. Additionally, New Cairo is considered to be one of the most prestigious areas in Cairo given its costly housing rates.

The Egyptian Administrative Control Authority suspended multiple officials and referred them to the general prosecution for the shortcomings in facing the consequences of the unstable weather due to heavy rains that revealed the drawbacks in the drainage system in the entire city.

30

SOM design proposal for new capital Cairo

SOM Consulting Partner, SOM city planners developed the initial framework and core principles of a sustainable new city in Egypt. Designed in harmony with the local environment and shaped by the natural landscape, the vision for this new city was created to specifically meet the needs of a modern city with a burgeoning economy.

Urban effects of current constuction

Learning from nature

Google earth image year 2016

Google earth image year 2019

Self-organized patterns captured from new Cairo location.

The construction of a new capital city started at the beginning of year 2016, ignoring the original design from SOM and without taking into consideration the main design aspect which was to have a sustainable new city. All of that will probably lead to the same results which cause the 5th settlement inhabitants to suffer during the rain season, which has become longer for the last decade.

As “There is no better designer than nature” [Alexander MacQueen] and zooming into the desert as it is the site for most of the new cities in Egypt, we can find the beauty of the nature design in “Self-organized patterns”.

These patterns are formed through hundreds of years. Some of these patterns are generated by quite simple rules, others by complex factors like; currents, wind, gravity and sun heat (John, 2014). These designs generated from nature works in the most efficient way. So, designing against the nature is not the solution because nature always wins.

And as an early Indicator for this problem, The figures above record the urban transformation during just 3 years from the beginning of construction.

31

2

Egypt Map

Marsa Alam 300 km

600 km

Siwa

Baharia

Farafra

Dakhla

32

Kharga

Cairo

New Cairo

a

33

2

34

Siwa Oasis

35

2

Siwa Oasis Historical and Cultural Background Firstly, Siwa oasis is considered to be one of the ancient oases since Pharaohs’ days, called the oasis “mercy islands” as they represented the resting place for travelling tribes in the desert. The ancient Egyptian name of Siwa was “Sekht-am” which means the palm land. Siwa is located in Egypt’s remote western desert, about 60 feet below the sea level. The total area of Siwa is 1088 kilo meters and it contains more than 300 fresh water streams and springs, populated by eleven traditional tribes totalling 20,000 people [Climate Siwa,2014]. Siwa oasis has a dry hot summer reaching 39°C and cool winter reaching 5°C [Dumairy, (2005)].

Wind rose

Tempreatures

36

37

2

Siwa Oasis

Siwa is popular for its palm and olive trees due to its location and the presence of hundreds of fresh water streams and springs, thus considered to be an agricultural oasis. It is one of the few Egyptian oasis communities that have managed to retain most of its traditional characteristics. Shali’ the ancient saltmud brick ‘kershef’ fortified dwellings was built in the 13th century. Dwellings were built side-by-side along steep, narrow and winding dirt roads, yet largely abandoned and left to collapse. Recently, heavy unusual rains damaged the dwellings, leading the population to abandon Shali searching for more space, dismantling any building materials and fixtures they could rescue to erect new. At the same time, the newly developed initiatives did not adequately consider the impact on the environment.

Land was rapidly purchased by outside investors, the social fabric of the region started to change and traditional methods of sustainable use of resources were no longer practiced [Climate Siwa,2014].

38

39

2

Case Studie Traditional Desert Buildings in Siwa Oasis Cases study The Karsheef technique: This construction technique is described in the report of the “journey” of Abu Abd Allah Muhammad Ibn Battuta, a rich Berber that in the 14th century has his siyaha (as he call that would mean to flow like water), the hajr: the religious pilgrimage through the Egypt desert. In his report he says: “[…] we arrived at Taghaza, a town without resources who has a curious feature: houses and mosque are made of blocks of rock salt and have the roof covered in camel leather There are no trees, just sand and a salt mine salt blocks are very small: 20 to 60 cm even for building of three or four levels. This was possible thanks to the very strong conjunction between salt blocks and salty mortar [Martines,2014].

In fact, when the wall was composed, the salty blocks surfaces, connected by the humid mud, left some salt starting a slow process of binding that in few years granted a monolithic behaviour of the masonries. In the composition of the wall were left some spaces that, in the connection process, could give place to the development of salt crystallization that binds the materials. Therefore, was generated, around salt blocks, a boundary of ligature in which the new generated crystals binds chemically and mechanically the mortars to the blocks. An incredible process of indifference between “inert” and binders makes these structures behaviour like monoliths. In the ancient part of the city, on the urban wall, which is exposed to wind and rainfall, it is possible to observe a particular condition for the creation of crystals. By analysis (conducted by Fratini F., Rovero L., Tonietti U.), the Tiin have proved to be composed of sodium chloride, magnesium, gypsum and other minerals [Martines,2014].

40

Crystals from Karsheef

The realization of a wall in Karsheef

Remain of Karsheef

Remain of Karsheef

41

2

Case Studie Adrere Amellal indigenous eco hotel in Egypt by EQI

Site plan

Lighting system (illuminated by natural light/ candle light)

heat during the day and maintain a cool interior, then radiate heat at night when the temperature drops. All windows are sized and placed speGround floor plan cifically to catch the desert breezes and elimAn eco-lodge so sensitive to its environment it inating the need for air conditioning – heat is does not offer wifi, phone service, electricity, or obtained through wood-burning braziers. the usual trappings of contemporary comfort.

Instead, a visit to the hotel frees you from the Oil lamps and candles are the only source for industrialized world and presents a window into light after the sun sets, transforming the interior history, it allows you to experience the night sky, into a more cavernous protected environment lake breeze, and desert landscape as it has al- with constant flickering light that highlights the various textures of the masonry construction and ways been enjoyed. natural plaster finishes. However, is the revival of Renovated by the environmental quality interna- the disappearing craftsman who have shaped tional (EQI), the structures are made of a combi- the area for thousands of years. The beds are nation of kershef (a mixture of rock salt and mud), made of rammed cotton and the simple furnishstone masonry, and carved out dwellings from ings made by hand using ancient techniques. the large mountain that hosts the lodge. Return- More than a hospitable temporary accommoing to the fundamentals of design, all aspects of dation, the Adrere Amellal hotel is a testament the buildings are aimed at naturally maintaining to local material, labour, and methods preserved basic comforts. The thick earthen walls absorb through its renovation.

42

Ariel view shows Structure with various wall finishes blends with the landscape.

43

2

Siwa Urban Growth

2020

1990

2000

Siwa urban growth through time 44

2010

North Siwa oasis (Sand stones Hills)

South Siwa oasis (Barchanoid Sand dunes) 45

46

Siwa Oasis has Created it’s barrier

Erosion Vs Cementation process Learning from natural cementation process and erosion by analysing sand-scape and sand rock formed by natural cementiation process during hundreds of years. The photo was captured by google earth Desert-scape in Siwa.

47

2

Sand Life Cycle

From grain of sand to sand rocks then again grain of sand this is the natural process that happens in nature due to many factors like erosion and solidification. This cycle in each phase creates many possibilities and functions for humans activates the research focused in studying and simulating this natural process through computational process to generate sustainable design for the desert cities.

48

So

lid ific

at

io n

Sand-rocks

Sand dunes

Sand-rock Hills

Er os io n

Sand grains

49

3

Design Research 3.1 The Invisible Flight Patterns of Birds 3.2 Sand Travel Diagram ”STD” 3.2.1 ”STD” in 2D 3.2.2 ”STD” in 3D 3.3 Site Analysis 3.3.1 Topography 3.3.2 Particles Simulation 3.4 Topology Deformation 3.4.1 Carved 3.4.2 Build up 3.5 Site Profile

50

51

3

The Invisible Flight Patterns of Birds

Spanish photographer Xavi Bou captures dynamic images of birds in motion, and uses digital manipulation to display their flight paths as flowing, contorting ribbons in ‘Ornitographies’.

Flying bird

Patterns of Bird

End

Start

Patterns of Bird through time

52

53

3

Sand Travel Diagram 2D

Time Using 1000 particles effected with defined force and speed .and recording the effect by drawing the particle travelling path during specific time resulted this what I call sand travel diagram.

Speed Depending on sand physical properties (Friction,Grain size,Silt,Displacement)

Force Applying force in defined direction with known pattern follows the desired scale.

54

Particles 1

Particles 2

Particles 3 Sand particle Shifted

Force

Path

Sand particle

End

Start

Time

Curves 1

Curves 2

Curves 3 55

3

Sand Travel Diagram 2D Applied on plane surface

56

1

2

3

4

5

6

7

8

9

Start

End

Time : Variable

Speed: 5 m/s

Force: North wind

57

3

Sand Travel Diagram 3D Applied without collision plane surface

58

1

2

3

4

5

6

7

8

9

Start

End

Time : Variable

Speed: 5 m/s

Force: North wind

59

3

Site Analysis Site topography

2km

High

Low

2km Site top view

60

Topograpy lines

Inputs for particles simulation

Sand particle Shifted

Force

Path Sand particle

End

Start

Time

Run the particle simulation on the site to get the “sand travel diagram “ Time : Variable

Speed: 5 m/s

Force: Wind Actual Wind : S70 o E Effective wind :10%

61

3

Particle Simulation Using particles as simulation output

Particles top view after wind simulation

62

Paticles as soldified mass

Paticles as soldified mass

Particles after wind simulation

Site topograpy 63

3

Particle Simulation Using “STD” curves as simulation output

Sand travel curves

64

Curves as soldified mass

Curves as soldified mass

Sand travel curves

Site topograpy 65

3

66

Site Topology Deformation

Site topography -Top view

Sand travel curves -Top view

Site topography -Perspective

Site topography -Perspective

Using sand travel curves as input for next simulation to record the difference in wind directions and sand flow.

1- Using the carves as curved to site topography.

2- Using the curves as build up to site topography.

1- Site carved topography.

2- Site build up topography.

67

3

Sand Travel Simulation Carved to site topography.

68

Site topography -Top view

Sand travel curves -Top view

Site topography -Respective

Site typography -Prospective

Curves as solidified mass -Top view

Result -Top view

Curves as solidified mass -Respective

Result -Respective

69

3

Sand Travel Simulation Build up to site topography

70

Site topography -Top view

Sand travel curves -Top view

Site topography -Respective

Site topography -Perspective

Curves as solidified mass -Top view

Result -Top view

Curves as solidified mass -Perspective

Result -Perspective

71

3

Sand Travel Simulation Results By analysing the results of the current situation and the two deformed topographies, it was found out that the sand flow usually goes through same paths With small differences between the build up and curved topographies options but with high difference of density and speed of the flow.

1

2

3

Zoom in situation “A” Density Speed Decay

1

2 Zoom in situation “B”

Density Speed Decay

72

3

1- Original topography

1- Original topography

2- Carved to site topography

3- Build up to site topography

Situation “A”

Situation “A”

Situation “A”

Situation “B”

Situation “B”

Situation “B”

2- Carved to site topography

3- Build up to site topography

73

4

Urban Proposal 4.1 Site Profile 4.2 Iterative Design Process 4.3 Simulation 4.3.1 Sand-travel Diagram 4.3.2 Dune-field Simulator 4.4 Results 4.5 Zone1 (Erosion) 4.6 Urban Proposal 4.6.1 Iterative Designs 4.6.2 Final Proposal

74

(Macro)

75

3 4

Site Profile

Form proposed site to new urban growth for Siwa oasis 2km by 2km . Section had been selected to be designed this section has both sand dunes and sandstone hills and had dimension of 2*0.4 km.

76

2km

2km

Cutting planes

2km 0.4km

77

4

Iterative Design Process

Maco

Meso

Micro

78

Site Profile

Feedback

Particles wind flow simulation Results

Sand dunes simulation

Results

Topography

Drainage water simulation

Results Output

79

4

Sand Travel Diagram

Simulating 20k particles divided equally to site topography.

Solidified mass

Sand travel curves

Site topography

Collective axonometric

Exploded axonometric 80

Top view shows Sand travel diagram in 3 months.

Particles : 20 k Actual Wind : S70o E

Time-25%

Effective wind :10% Wind Speed: 5 m/s

Time-50%

Time : 3 months

Time-75%

Time-100%

Sand travel -3 (Months) 81

4

Dune-field Simulator

Sand dunes simulator was used to create the heat map for expected dunes types ,shape and dimensions for the study area.

Inputs

Output

Dune type: Barchanoid Actual Wind : S70 o E Effective wind :10% Wind speed :5.4-8.5 m/s

Scale (0,30) T=320 Height range (0,30)

Heat map for sand dunes

Sand dunes section

Apply simulation output to site topography

Site Topography 82

Topography with sand dunes

Sand dunes movement and deformation study through 3 months time recorded with average wind speed of 5.4 m/s .

Ortho

Plan

Right Wind-50%

Wind-75%

Wind-100%

Elongation -3 (Months) 83

4

Dunefield Simulator

Wind speed

5.4-8.5M/s

84

Elevation gain

14M (Max.) 85

4

Results

There were three main results as output from site topography and sand dune, drainage water and sand flow simulations.

Extremely high density flow High density flow

1- High density flow

2- Define main and secondary roads according to flow density

86

Zone 1 (Sandstone hills) Zone 2 (Sand dunes)

3- Divide site profile to two main zones Sandstone hills and sand dunes

87

4

Zone One (Erosion) Natural erosion The movement of rock pieces from one place to another, once they have been loosened by the action of physical or chemical weathering, is known as erosion. Small pieces of rocks, sediment, and even soil are moved away by the action of natural geological agents such as flowing water, blowing winds and melting ice of glaciers under the influence of gravity. The process of erosion is complete when the journey of all particles falling and flowing under gravity is done with and all the sedimentation gets deposited and settles on the surface. This is the process of deposition that is technically speaking a part of the process of erosion. If erosion can be thought of as a sequence, it includes detachment, entrainment, transport, and finally deposition.

Detachment is end process of weathering that finally results in loosening of rock particles. Sand is the resultant of this erosion and sand dunes are the resultant of deposition.

Honeycomb weathering (as shown in the photos) occurs around the world, but the origin is still a matter of controversy. Wind erosion, frost cracking and salt weather suggested. A type of bee cavity causes the breakdown of mineral grains due to the evaporation of salt water on the rocks. These cavities can hold salt water and as long as the sun reaches the water inside, the water evaporates and the cavities expand. When the light cannot reach the water inside, the process stops. It is also believed that algae that live on the surface of rocks protect the walls that separate cavities (barrier) from evaporated erosion.

Natural forms of rocks erosion

88

Studying two examples for architecture that were carved in rocks : Matmata town Tunisia is a small Berber speaking town in southern Tunisia. Some of the local Berber residents live in traditional underground “troglodyte” structures.

The Zelve Monastery Turkey. is a Byzantine-era monastery that was carved into the rock in pre-iconoclastic times. It is part of the Zelve open air museum.

Matmata town

Zelve Monastery

Matmata town

Zelve Monastery

89

4

Iterative Design options Zone 1

The digital parametric process that was applied to zone 1 was inspired from the erosion that happens in nature and follows the same process to create desert buildings carved in mountains.

The sand travel curves were the main design driver during the parametric digital process. The “STD” curves were classified in two main types of curves: one is extremely high-density flow and the other is high-density flow.

The extremely high-density curves have value of 10m range in creating erosion and the high-density curves has value of 8m range in creating erosion.

Extremely high density flow High density flow

Units according to flow lines.

Define road according to flow lines.

Design process

90

Define the height of units due to flow.

Iteration 1

Iteration 2

Iteration 3

Iteration 4

Iteration 7

Iteration 8

Generation 1

Iteration 5

Iteration 6 Generation 2

91

4

Urban Proposal Generation 3 (final) Generation 3 was selected as urban proposal. It was designed with same generative design process because it has the best architectural qualities.

Inputs: the extremely high-density curves have value of 10m range in creating erosion the high-density curves have value of 8m range in creating erosion.

Top

Top

Top

Front

Front

Front

Erosion 30%

Erosion 65%

Deformation through time 92

Erosion 100%

Final urban proposal

93

5

Design Proposal

(Meso)

5.1 Iterative Design Process Zone 2 5.2 Zone 2 (Sand Shifting) 5.3 Design objective 5.4 Form finding 5.4.1 Project Program Optimization 5.4.2 Structural Optimization 5.4.3 Wind Pressure Simulation 5.5 Drawings 5.5.1 Exploded Axonometric 5.5.2 Plans 5.5.3 Sections 5.6 Renders 5.7 Micro to Urban

94

95

5

Iterative Design Process

Maco

Meso

Micro

96

Project plot

Feedback

Particles wind flow simulation

Result Project program optimization

Structure simulation

97

5

Zone Two (Sand Shifting) Zone 2

Sand shifting is considered the main cause for desertification. To understand how desertification happens we must know more about sand dunes and Sand movement patterns. There are traditional anti-desertification methods that have been used in Egypt. However, with that size of development, implementation would be hard. All these obstacles must be overcome using environmental, economic solutions, with available materials and technologies.

Most of the tradition methods deal with sand shifting as a problem and try to block it and keep it away from cities and agricultural lands. In the design process, sand-shifting was used as potential because if sand was the building material, and by calculating the sand shifting rate, we could use it to build on the same site simultaneously while using the suitable tools.

98

Designing the obstacle

99

5

Design Objectives

Sand

Water

Time Sand Shifting

Speed

Erosion Vegitation

Force

Human activity

100

Objective

Parameters

Classification systems

Control sand shifting while creating Human activities within the geographical cycle of land .

The parameters to create human activities should be the parameters that control sand shifting itself (Time, Speed, Force)while considering the sand type is constant.

After defining the project which this case will be Tourism city and defining the project zoning and program were classified according to usage to Dynamic and Static.

Axis Attractor Slope Dune condition Open area

Dynamic

Salted (Meditation) Pure (Daily usage) Stored (Collected) Forestry Agriculture Decoration

Static

Urban activities Meditation Settlement Sports Interior Activities

Degree of control

Static

Dynamic

Environmental studies should be taken in consideration during controlling the sand shifting not to effect the natural system and the wild life of the surroundings places ,all of that should define the degree of control of sand shifting.

Zones with usage that can not be change or replaced during specific time period .

Zones with usage that can be change or replaced during specific time period .

101

5

Form Finding /

Project Program

Siwa recreational center Program

Core

Residence

Services

Entrance Reception Lobby Administration Vertical Circulation

Standard room Junior suite Superior room Suite Deluxe room

Restaurant Cafe Amenities Facilities Laundry Administration Vertical Circulation Ancillary

Entertainment

Educational

Urban activities

Gym Spa Salt lakes Administration Vertical Circulation

Planetarium Amphitheatre

Restaurant Cafe Open spaces Gardens

Static Dynamic

102

Manual Zoning

Cafe

Standard room Junior suite Superior room

Resturant Warehouse Kitchen

Suite

Amenities Facilities

Lifts Stairs

Deluxe room

Planetarium

Laundry

Reception Lobby

Gym Spa

Entrance

Salt lake

Auditorium Ancillary Open spaces Gardens

Direct relation Indirect relation Circulation

103

5

1

1 1

Form Finding /

Project Program

1

Project Program Optimization

1

1

4

1- Set relations between spaces

4

2

104

4 4

2 2 2

4 2

2- Run Octopus optimization

2

4

Run the optimization with target minimum area and minimum Intersection between spaces using octopus optimization tool in grasshopper.

• •

Minimum area Minimum Intersection between spaces

Direct relation Indirect relation Circulation

3- Final result 105

5

Form Finding /

Project Program Optimization

Amenities Loundary

Kitchen Restaurant

Plantarium

Spa

Entrance

Lobby

Rooms Stairs

106

Amphi theater

Caffe

Reception

Entrance

1- Define roads that goes with the high density flow.

2- Building zones result from optimization

3- Circulation result from optimization in each floor.

4- Connecting the circulation between floors to create dynamic circulation.

Amphi theater Loundry Kitchen

Entrance

Restaurant Spa

Lobby Rooms Entrance

5- Shaping building spaces around the main circulation.

107

5

Form Finding /

Structure

Structural optimization

Wool Thread Experiments | Frei Otto

The experiment has many steps. firstly, to connect all the points with straight lines then dipping the whole system under water, shaking it carefully and taking it out again.

After a time period the surface stickiness and the curability of the wool thread together with the cohesive forces on the water surface which bring it to half again and inform the end result. Wool-structure that real movement of water flow become abstract movement of wool structure, which results in coherent language of bending splitting curving nesting aligning and merging.

108

Wool Thread Experiments | Frei Otto

Structural optimization digitally

1- Connect all points with straight lines

2- Identify CV points-per lines, where forces are applied

4- Identify force effected area.

5- Digital threads configuration

3- Identify number of force points.

109

5

Form Finding /

Structure

Experiment (generation 1) Applying force of gravity and wind lateral force to the lines and adding three anchor points then materialize it.

Perspective

Top view

Top

Left

Time 25%

Time 50%

Time 75%

Simulation with force of gravity and lateral force 110

Time 100%

Experiment (generation 2) Applying force of gravity and wind lateral force to the lines and adding many anchor points and adding more open spaces in the shell then materialize it.

Top

Left

Time 25%

Time 50%

Time 75%

Time 100%

Simulation with force of gravity and lateral force 111

5

Form Finding /

Structure

Final result (generation 3) Applying force of gravity and wind lateral force to the lines and adding seven anchor points.

Stiffness 0.3 Distance multi 5 Max Binds 25 Force gravity 9.7 m/s² Force wind 5 m/s²

Define structure fixed points and boundaries

Fixed points boundaries

112

Structure simulation-connecting the wires between circuls and building boundaries.

Top

Left

Time 25%

Time 50%

Time 75%

Time 100%

Simulation with force of gravity and lateral force 113

5

Form Finding Process

Amenities Caffe

Kitchen Restaurant

Amphi theater

Plantarium Entrance

lobby

Rooms Stairs

114

Spa

Caffe

Reception

Entrance

1- Sand flow curves.

2- Define roads that goes with the high density flow.

3- Building zones result from optimization

4- Circulation result from optimization in each floor.

5- Connecting the circulation between floors to create dynamic circulation.

6- Shaping building spaces around the main circulation

7- Define structure fixed points and courts.

8- Structure simulation connecting the wires between circles and building boundaries.

9- Structure simulation-apply forces counter gravity and wind directions.

10- Materializing the structure thickness according to the simulation output.

11- Creating building skin and openings .

12- Define building skin with high translucency material regions.

Final project mass

115

5

Wind Pressure Simulation

The wind pressure study shows the pressure of the wind through horizontal and vertical section. The gradient colour from red the high pressure colours that means the sand dunes cannot form in these zones to the blue colour where low pressure allows for urban activities.

The results shows that the building is preforming in a good way and that all the courtyards are with minimum amount of sand and is a good places for urban activities.

116

Collected wind tunnels

117

5

Wind Pressure Simulation

-2 m

-7 m

-12 m

Horizontal wind tunnel -17 m

-22 m

-27 m

118

1

2

2

1

3 4 5

3

6

Vertical wind tunnel 4

5

6

119

5

Drawings

Project mass

120

High transparent layer

Building Skin

Structure

Spaces

Circulation Ramp

Ground and building boundaries

Exploded Axonometric 121

5

Ground-Floor Plan

Ground floor program: Garden : 534 m2 Main entrance : 400 m2 Lobby : 1000 m2 Administration : 500 m2 Vertical circulation : 215 m2 Reception : 1000 m2

Circulation

122

A

-25 m

B

B

-26 m -27 m

Lobby

-28 m

-29 m

-30 m

Courtyard -31 m

Stairs

-32 m

-33 m

Reception

-34 m

Entrance

-35 m

-36 m 5m

5m

A 123

5

First-Floor Plan

First floor program: Rooms garden : 534 m2 Amphitheatre entrance : 160 m2 Amphitheatre : 1380 m2 Spa & Gym : 550 m2 Rooms : 1950 m2 Cafe : 600 m2 Administration : 500 m2

Circulation

124

A

-20 m

-21 m

-22 m -23 m -24 m

Rooms

-25 m

B

B

-26 m

Courtyard Amphitheatre

-27 m

Cafe -28 m

-29 m

-30 m

Gym

-31 m

Stairs

-32 m

-33 m

Spa

-34 m

-35 m

-36 m 5m

5m

A 125

5

Second-Floor Plan

Second floor program: Amphitheatre : 1300 m2 Restaurant : 700 m2 Planetarium : 150 m2 Kitchen : 650 m2 laundry : 250 m2 Amenities : 650 m2 Courtyard : 150 m2

Circulation

126

A -17 m

-16 m

-15 m

-18 m -19 m -20 m -21 m Loundry

-22 m Amphitheatre -23 m -24 m

Planetarium

Kitchen

-25 m

B

B

-26 m Resturant

-27 m Resturant

-28 m

-29 m

-30 m

-31 m

-32 m

-33 m

-34 m

-35 m

-36 m 5m

5m

A 127

5

Layout

Layout : Entrances : 3 Courtyards : 4 Maximum height : 32m Building printed volume : 33372qm

128

129

5

+6 m

-9 m

-17m

-22m

-27m

130

Section A-A

131

5

+6 m

-9 m

-17m

-22m

-27m

132

Section B-B

133

5

Section B-B

Rooms

134

Courtyard

Rooms

Restaurant Cafe

Lobby

Amphitheatre

135

136

137

5

138

Exterior Shots

139

140

141

5

142

Interior Shots

143

5

144

Layout

145

5

146

Micro to Urban

147

6

Materility & Fabrication (Micro) 6.1 Materials 6.1.1 Sand solidification technology (SST) 6.1.2 Sand stone 6.2 Building Layers Materials 6.3 Siwa Robot 6.4 Building Layers Materials 6.5 Printing Time 6.6 Multi Scale Design

148

149

6

Materials Sand solidification technology (SST) A sustainable alternative was suggested by Professor Jason DeJong at the University of California at Davis in 2007. He used B. pasteurii, a natural bacterium that lives between sand grains and in soils, and that causes calcite (the most stable poly-morph of calcium carbonate, CaCO3) to precipitate, which glues the grains together and turns loose sand into solid rock. ‘‘Starting from a sand pile, you turn it back into sandstone,’’ DeJong explained, before making clear that there are no toxicity problems, that the treatment could be applied after the construction of a building, and that the structure of the soil does not change as the void spaces between the grains are filled in [The Engineer 2007]. DeJong’s method had one writer at Time magazine (which included DeJong’s findings on its ‘‘Best Inventions of 2007’’ list) to exclaim: ‘‘Mix urea, soil and calcium, inject a little bit o’ bug and voilà! The cementer bug feeds on urea and deposits calcite, which cements the soil together and turns shifting sand into sandstone’’ [Time 2007].

3D Printing with sand finally, explores the potential of sand as a substrate within a binding agent. In combination with a robotic arm, 3D printing of sand is an in situation digitally controlled construction process. It overcomes the need for traditional form-work and transportation of material, thereby reducing the grey energy.

150

bacillus pasteurii CaCO3

+ Sand Urea

+

151

6

Materials Sand stone

Studying sand physics and characteristics to know, how we could convert it to solid building material (solidification) and also we had to know what what is the meaning . Sand particle physics: In terms of the size of the particles used as geologists, sand particles range in diameter from 0.0625 mm (or 1/16 mm) to 2 mm. And it called on the individual particles in this size range of a grain of sand.

Sand grains are between gravel (with particles ranging from 2 mm up to 64 mm) and silt (smaller than 0.0625 mm particles down to 0.004 mm). Size specifications remained constant between the sand and gravel for more than a century, but was considered a small particle diameter such as 0.02 mmsand below Albert Atrberg in use during the early 2oth century. A 1953 engineering standard published by the American Society for rapid road transport and state officials determine the minimum size of the sand in the 0.074 mm.

152

A unique biotechnology start-up company have developed a method of growing bricks from nothing more than bacteria and naturally abundant materials. Having recently won first place in the Cradle to Cradle Product Innovation Challenge, bioMason has developed a method of growing materials by employing micro-organisms. Arguing that the four traditional building materials - concrete, glass, steel and wood - both contain a significant level of embodied energy and heavily rely on limited natural resources, their answer is in high strength natural biological cements (such as coral) that can be used “without negative impacts to the surrounding environment.” [Archdaily,2014]

153

6

Building Layers Materials

The building section consist of three main layers, each layer has a different material mixture that reflects its required function.

154

Building skin Structure optimization curves

Structure thikness

High transparent skin

155

6

Building Layers Materials

Structure optimization curves

Structure thickness

156

Building skin

High transparent skin

157

6

Siwa Robot

Rotation joint Photovoltaic panel

Fusion Feresnel lens

Print Head

Kuka Robotic arm Battery Foot

(Total 4)

The printing robots used are quite energy efficient when it comes to the energy consumption rates for the operation process of the robots, their monitoring and their on-site deployment. Moreover, the printers make use of solar energy on timely basis to operate.

The printers perform as efficiently on implementing complex structures as they do for relatively less complex structures.

As an application for the Sand Solidifying Technology (SST), and during the construction process of new desert communities, the printers make use of pre-considered facts regarding the wind speed, sand shifting speed rates and materials properties.

158

Leg

(Total 4)

Photovoltaic panel

Kuka head

Fusion head

Robot’s main body

159

6

Printing Time

Sand travel diagram will be used to calculate the amount of sand flow coming and where exactly it will come from. Building volume 33372 QM to be printed.

Robotics -Printing techniques - Sensory system -Interact with physical world

+ Sand shifting Speed

Time estimation

30 cm per day with wind speed 5 m/s

- Multi axis 3D changes with time

+ Material Properties -How long it takes for 1 layer to solidify

160

printing

Robots building the structure simultaneously with sand shifting rate

Time 25%

Time 50%

Time 100%

Sand shifting and construction

161

6

Multi Scale Design

Selected site scan

162

Converting the site terrains to point The robots would be provided with cloud..

Self-Organizing System to ‘scan’ the site database and find the changes that happens to sand dunes while construction.

The program space would change The robots would be supplied with ma- The program space would change simultaneously while construction to terials that creates stones out of sand simultaneously while construction to adapt with sand shifting. this material can be injected in sand adapt with sand shifting. dunes.

163

7

Conclusion

The research has gone through many phases of study, simulation and generative design experiments on many levels, starting from urban through architecture to fabrication and materialization.

During the research part and while defining the challenges that the Egyptian government faces in building new communities in the desert -as arid areas- the focus was to learn from nature and to generate the solution out of the problem, by studying the cycle of sand solidification and erosion. Siwa oasis was selected as project site because of its location and the long history of Siwian people in dealing with the desert. The procedure involved learning from their traditional building techniques and material usage to build efficient architecture in the desert.

The urban studies on the selected site addressed the possibilities of new urban growth in Siwa. The study introduced the “Sand Travel Diagram STD” which records the movement of sand particles under the effect of wind and gravity through time intervals. The STD was applied on three topography alternatives and the result was analysed to get to understand how the sand movement reacts to that difference.

The design proposal involved dividing the proposed site in two zones taking in consideration the results from the ‘STD’, and drainage water simulations. The first zone is composed of sand rock hills and second one contains the sand dunes.

164

-For sand rock hills (zone 1), generative design process used ‘STD’ and drainage water simulations to simulate the effect of erosion (happening on the micro level in rocks) which is then applied on the urban fabric of zone 1.

-For sand dunes (zone 2), generative design process used ‘STD’ and sand dune field simulator to define the site boundaries and as an input for the structure analysis for the building.

The building zones were optimized digitally to fit into this boundary creating efficient circulation.

Lastly, the material and fabrication were studied as sand and salt are the main building materials and the robots are to be the building labour of the new Siwa community in the desert. Robots perform more efficiently in arid areas than humans and they have shown an ability to build complex structures using pre-considered facts regarding the wind speed, sand shifting speed rates and materials properties.

The proposal hopes to introduce generative design technologies as an alternative to the development and construction of new communities techniques in the desert, especially that the STD technique has proven to be a main factor of influence in predicting the sand behaviour throughout the design, the assessment, and execution of the project, despite of its usually-high initial costs and its need for the experience and specialization. It lives up to be an environmental and a futuristic sustainable alternative.

165

Appendix Physical model

166

167

References

1. African Union (2006) Launching of the Green Wall Sahara Programme. Division of communicationand information, press release 6. http://www.africaunion.org/root/ua/Actualites/2006/decembre/ green%20wall%20launch.doc. Viewed 30 April 2016 2. AU/CEN-SAD (2009) Plan of action for the implementation of the Great Green Wall of the Sahara and Sahel Initiative. Draft for submission to the AU Executive Council. Addis Ababa, Ethiopia, 1–3 February 2009 3. Balmond C (2002) Informal. Prestel, London, p 119 4. Bagnold RA (1941) The physics of blown sand and desert dunes. Methuen, London Bak P (1996) How nature works: the science of self-organized criticality. Copernicus Press, New York.

5. Bricks Grown From Bacteria. 1 February, 2014. http://www.archdaily.com/472905/bricks-grownfrom-bacteria. Viewed 24 May 2016.

6. Borges JL (1974) Fragments from an ‘‘Apocryphal Gospel’’, from the collection ‘‘In Praise of Darkness’’, Dutton, New York. Original quote: ‘‘Nada se construye sobre piedra; todo se construye sobre arena, pero debemos construir como si la arena fuese piedra.’’

7. Chang, I., Im, J., & Cho, G. C. (2016). Introduction of Microbial Biopolymers in Soil Treatment for Future Environmentally-Friendly and Sustainable Geotechnical Engineering. Sustainability, 8(3), 251.

8. Climate Siwa - Climate graph, Temperature graph, .Climate-Data.org. Online: http://en.climatedata.org/location/32202. Accessed: 14/01/2014 9. Dumairy, A. (2005). Siwa Past and Present. Alexandria.

10. Dosier, G. K. (2014). U.S. Patent No. 8,728,365. Washington, DC: U.S. Patent and Trademark Office.

11. DeJong JT, Fritzges MB, Nüsslein K (2006) Microbially induced cementation to control sand response to undrained shear. J Geotech Geoenviron Eng 132:1381–1392 12. Dell’Amore C (2009) Africa-wide ‘‘Great Green Wall’’ to Halt Sahara’s Spread? National Geographic News, 28 December 2009. http://news.nationalgeographic.com/news/2009/12/091228great-green-wall-trees-senegal-sahara-desert.html. Viewed 3 March 2016 13. Hereher, M. E. (2010). Sand movement patterns in the Western Desert of Egypt: an environmental concern. Environmental Earth Sciences, 59(5), 1119-1127.

14. Ignatescu,v., (2014). Generating Sand Dunes (Unpublished master’s thesis).

15. Jauffret S, Woodfine A (2009) Scope and pre-feasibility study on the Great Green Wall for the Saharan and Sahel Initiative (GGWSSI). Hernel Hempstead, Hertfordshire 16. Kulik, A., Shergill. I., & Navikov. P. (2012). Stone Spray Soil Solidifying Robot.

17. Larsson, M. (2010). Dune: Arenaceous Anti-Desertification Architecture. Macro-engineering Seawater in Unique Environments Environmental Science and Engineering, 431-463.

18. Lipson, H., & Kurman, M. (2011). Fabricated: The new world of 3D printing.

19. Le Metayer-Levrel G, Castanier S, Orial G, Loubiere JF, Perthuisot JP (1999) Applications of bacterial carbonat ogenesis to the protection and regeneration of limestones in buildings and 168

historic patrimony. Sediment Geol 126:25–34 20. Manaugh G (2009) Sand/Stone. Blog entry, Bldgblog, April 2009. http://www.bldgblog. com/2009/04/sandstone/. Viewed 1 March 2016 21. Martines, G. (2014, August). The karsheef: Problems of cultural and environmental conservation. In Earthen Architecture: past, present and future: proceedings of the International Conference on Vernacular Heritage, Sustainability and Earthen Architecture, Valencia, Spain, 11-13 september 2014 (pp. 239-244).

22. Nemati M, Voordouw G (2003) Modification of porous media permeability, using calciumcarbonate produced enzymatically in situ. Enzyme Microbiol Technol 33:635 23. Potra, M. D. (2013). 3D Printing in Architecture Experimenting in the Desert (Unpublished master’s thesis). Politecnico di milano.

24. Rong, H., & Qian, C. (2013). Microstructure evolution of sandstone cemented by microbe cement using X-ray computed tomography. J. Wuhan Univ. Technol.-Mat. Sci. Edit. Journal of Wuhan University of Technology-Mater. Sci. Ed., 28(6), 1134-1139.

25. Rovero, L., Tonietti, U., Fratini, F., & Rescic, S. (2009). The salt architecture in Siwa oasis–Egypt (XII– XX centuries). Construction and Building Materials,23(7), 2492-2503.

26. Shen, W. (2001). Sand Dune Stabilization with Plants in China. Combating Desertification with Plants, 337-346.

27. Staunton, S. (2008). Diffusion processes. In Encyclopedia of Soil Science (pp. 183-198). Springer Netherlands.

28. The Engineer (2007) Editorial, bacteria help protect from quakes. 23 February 2007.http://www. theengineer.co.uk/news/bacteria-help-protect-fromquakes/298382.article.Viewed 3 April 2016.

29. Tag Archives: Generating Sand Dunes. November 10, 2014. https://wewanttolearn.wordpress.com/ tag/sand/. Viewed 23 May 2016.

30. Time (2007) Mighty microbe. The best inventions of 2007. November 2007. http://www.time.com/ time/specials/2007/article/0,28804,1677329_1678027_1677996,00.html. Viewed 3 April 2016.

31. van Paassen LA, Daza CM, Staal M, Sorokin DY, van der Zon W, van Loosdrecht MCM (2010) Potential soil reinforcement by biological denitrification. Ecol Eng 36:168–175.

32. Whiffin VS, van Paassen LA, Harkes MP (2007) Microbial carbonate precipitation as a soil improvement technique. Geomicrobiol J 24:417–423 33. Martineau, John (2014). Designa: Technical Secrets of the Traditional Visual Arts. New York: Bloomsbury .

34. “Xavi Bou Traces The Invisible Flight Patterns Of Birds.” IGNANT, November 15, 2018. https://www.t

169