22R0002_Attch9-Example Geotech Report.pdf

FILE: 19.933-20

GEOTECHNICAL REPORT

RPL MFH COMMAND UNITS

MORÓN

ARAHAL AERIAL BASE (SEVILLE)

Client: CASTAÑO Y ASOCIADOS CONSTRUCCIÓN SOSTENIBLE S.L.

Seville, November 10, 2.020

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AWARDED CONTRACTOR WILL

CONDUCT OFFICIAL GEOTECHNICHAL SURVEY

INDEX

1. PRELIMINARY DATA

1.1. BACKGROUND

1.1.1. Name and location of site

1.1.2. Documents of the offer

1.1.3. Previous documentation

1.2. BASIC PROJECT DATA

1.2.1. General characteristics of the construction

1.2.2. Predictable geotechnical problems

1.3. LOCATION DATA

1.3.1. Geographical location

1.3.2. Historical evolution

1.3.3. Geological framework

1.3.4. Regional geology

1.3.5. Lithology

1.4. Seismicity degree of the area

1.5. Geothecnical risks

1.5.1. Recognition scheduling

2. GROUND RECOGNITION

2.1. RECOGNITION WORKS CARRIED OUT

2.1.1. Boreholes

2.1.2. Soil pits

2.1.3. Other field tests

2.1.3.1. Standard penetration test within a borehole

2.1.4. Water table investigation

2.1.5. Sampling

2.1.6. Laboratory tests

2.2. DISTRIBUCION OF GEOTECHNICAL UNITS

2.2.1. Geotechnical units detected

2.2.2. Water table

2.3. SITUATION OF THE RECOGNITION POINTS

2.4. GEOTECHNICAL CHARACTERISTICS OF THE LAND

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2.4.1. Excavability

2.4.2. Stability of the soil pit wall

2.5. SEISMIC CHARACTERIZATION OF THE LAND

2.6. Water caracteristics

3. FOUNDATION SOLUTIONS

3.1. ANALYSIS OF THE GEOTECHNICAL PROBLEMS RAISED

3.2. PROPOSED FOUNDATION TYPES

3.3. DIRECT FOUNDATION THROUGH INSULATED ELEMENTS

3.3.1. Simplified allowable load for direct foundations

3.3.2. Direct foundation settlement

3.3.3. Other geotechnical parameters

3.4. SOIL PERMEABILITY

3.5. SPECIFIC CONSIDERATIONS IN EXPANSIVE SOILS

4. SUMMARY AND CONCLUSIONS

ANNEX 1: SURVEY LOCATION PLAN

ANNEX 2: SOIL SURVEY REPORT

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MEMORY

1. PRELIMINARY DATA

1.1. BACKGROUND

1.1.1. Name and location of site

The present geotechnical study is written at the request of CASTAÑO Y ASOCIADOS CONSTRUCCIÓN SOSTENIBLE S.L., for the work whose location is detailed in the following table:

WORK REEMPLAZAR VIVIENDAS DE COMANDACIÓN EN MFH

LOCATION MORON DE LA FRONTERA AERIAL BASE

MUNICIPALITY ARAHAL

PROVINCE SEVILLA

1.1.2. Documents of the offer

The work of this report has been carried out in accordance with our offer of reference 19.933-20, conveniently accepted.

However, due to the fact that the offer was based on an estimation of the surveys and tests, it is possible that the reality of them differs in their final measurement due to differences in depths, impossibility of execution of tests, etc.

1.1.3. Previous documentation

For the preparation of this report, the following previous documentation has been used, besides from the usual bibliography and technical regulations:

Location plan provided by the client.

Site planned for the surveys, according to the client’s proposal.

Since these documents are held by the client, they are not reproduced in the present, only providing the relevant data in each case.

It should be mentioned that the information provided has been incorporated into this report in those points where it is expressly mentioned and that have been considered of interest. In this sense, it should be noted that the results and data presented have been interpreted without questioning their certainty or validity since they are signed by accredited responsible companies or professionals, which does not imply the its assumption.

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1.2. BASIC PROJECT DATA

1.2.1. General characteristics of the construction

According to the data provided by the client to carry out the study, the most relevant characteristics of the construction planned for this purpose are the following:

TYPE (USE) TWO HOUSES

SURFACE OF THE FLOOR OF EACH HOUSE ≈250 m2

NUMBER OF PLANTS ABOVE GRADE 1

NUMBER OF PLANTS UNDER GRADE 0

TYPE OF STRUCTURE Concrete porches

STRUCTURAL LAYOUT IN PLANT Rectangular

REPRESENTATIVE DIMENSIONS IN PLANT 25 x 10 m

PLANNED LAND MOVEMENT Not specified

1.2.2. Predictable geotechnical problems

The existence of the following incidents with possible repercussion from a geotechnical point of view, have been previously reported.

The current use of the plot is for a single-family home.

There are no party buildings within the plot of study.

The current houses are founded by shallow foundation.

The plots are located in a residential and military environment.

The plot is next to a communication road called Avenida "G".

There are service networks around the plots.

There are signs of expansiveness manifested in systematic cracking of the surface layer of the ground.

The parcels are sub-horizontal, with a descending slope towards the South. There is a total difference in level between the limits of the plot of about 2.0 meters

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This information has been received and taken into account in carrying out the surveys, and in the actual writing of this report.

1.3. LOCATION DATA

1.3.1. Geographical location

The works that are the subject of this report are located at the south area of the municipality of Arahal, as located in the attached aerial photograph obtained from the Google Earth application:

1.3.2. Historical evolution

From the reconstruction by means of digital techniques of the continuous image of the territory of Andalusia carried out by the Junta of Andalucía, in collaboration with the Cartographic and Photographic Center of the Ministry of Defense, it is possible to obtain the compared images of the surroundings of the works among those obtained from the well-known “flight of the Americans”, made between the years 1956-1957 and the most current photograph, as illustrated in the following images:

It is possible to observe that the area is quite altered from the oldest photo in terms of its morphology and use. In the 1,956 photographs, everything was a military practice field, and the American military zone is not appreciated.

There are no signs of channels or morphological alterations that could influence the building to be projected.

The most recent evolution of the plot can be illustrated by the photographic sequence of the last years accessible from the Google Earth tool:

2.004 2.011

The images show that there haven’t been any changes, from the construction of the houses to the present day, only observing alterations in the area due to the installation of current services such as, sanitation and supplying of the road, located to the east of the houses.

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1.3.3. Geological framework

Based on the cartography and official technical documentation, as well as the visit to the area, the most relevant aspects from a geological point of view are described below.

The area under study is included in sheet 1,003 “Utrera” of the MAGNA series at a scale of 1: 50,000 from the Geological Mining Institute of Spain, whose extract is collected below:

Detailed geological map from the study area. Sheet 1,003 Utrera. E: 1:50,000 MAGNA series. IGME.

1.3.4. Regional geology

The location is located about 40 km to the East of the Sevillian capital in an area of soft topography, flattered towards the West, over materials from the Guadalquivir Depression and more abrupt to the East coinciding with the Subbético mountain range.

The fluvial network is established by the Cuerno stream in the NW and the Guadaira River and its tributaries to the S and SW, as well as other secondary streams at the E end, coinciding with semi-endorheic or poor drainage areas.

Geologically we can recognize to the NW and the W the post-orogenic materials of the Guadalquivir Depression composed mainly of:

Parautochthonous units of marl or marl-limestones (biosparites or micrites) of white-yellowish or grayish tones, rough to the touch, slightly siliceous and with abundant traces of radiolaria and diatoms. To a lesser extent, outcrops of detrital material have been described on this formation. An approximate value for the thickness of this unit cannot be set.

Miocene: Discordant and overlying the previous unit, numerous outcrops of sandstones, sands and yellowish sandy loams (sub-arches) with abundant fauna (true lumachelae). A thickness of 60 m is estimated for this formation.

On the contrary, towards the South and towards the East the Subbetic materials emerge, corresponding to the Triassic period, which in this area are represented by:

Clays, marls, sandstones and gypsum: Triassic. It is a chaotic mixture of clays with minority levels of gypsum, marl and sandstones of variegated or reddish tones.

Plaster levels (saccharide or spatic) are very common within this plastic clay mass. It outcrops widely in a good part of the population and its thickness is several hundred meters.

Limestones, Dolomites and Carniola: In the eastern sector of the population a fine band of limestone-dolomitic material and carniola can be individualized in a package of metric thickness and with a sub-parallel arrangement to the general direction of the main tectonic features of the region (SW -NE). These are dark dolomitized and brecciated limestones that can be associated with aquifers hanging over the Triassic platform.

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Finally, there are overlying and discordant quaternary deposits of diverse nature:

Colluvial, generally clayey at the foot of the steepest slopes.

Alluvials and riverbed deposits in the middle and lower zones of the longitudinal profiles of rivers and streams.

Anthropic or filled deposits: linear or filled with quarries, gravel pits, etc ...

1.3.5. Lithology

According to the lithology described in the geological cartography, the formation involved in the site are the Q quaternary deposits, formed by conglomerates, sands and shales with abundant calcareous nodules.

1.4. Seismicity degree of the area

According to the NCSE-02 Earthquake Resistant Construction Standard, the geographical area in which the plot under study is located is characterized by the following parameters:

PROVINCE SEVILLA

LOCALITY ARAHAL

BASIC ACCELERATION, ab (* g) 0,06

The application of the NCSE is mandatory in general in the construction and rehabilitation projects of buildings, with the following basic exceptions:

In buildings of moderate importance.

In buildings of normal or special importance when the basic seismic acceleration ab is less than 0.04 g, where g is the acceleration due to gravity.

In constructions of normal importance with frames well braced together in all directions when the basic seismic acceleration ab is less than 0.08 g.

However, the Standard will be applicable in buildings with more than seven floors if the calculation seismic acceleration, ac, is equal to or greater than 0.08 g.

1.5. GEOTHECNICAL RISKS

As shown in sheet 59 "Badajoz" of the General Geotechnical Map at 1: 200,000 scale of the IGME, the general problems of this area are classified as follows:

The environment of the facilities is described as I2, included in the Guadiana

Depression, and characterized as follows:

Favorable construction conditions (yellow color), with lithological and geotechnical problems.

Lithology: marls, clays, sandstones and thin layers of limestone.

Relief: shapes from smooth to abrupt.

Permeability: locally imposed by the predominant lithological group.

Drainage: poor in most of the area, and acceptable due to surface runoff in steep areas.

Load capacity: average with possible appearances of medium or differential seats.

In relation to the possible risk due to expansive clay materials, the Preventive Map of

Risks due to Expansion of Clay in Spain at a scale of 1: 1,000,000 published by the IGME shows the presence of predominant expansive clays or areas with expansion problems, that represent a high to a very high risk.

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1.5.1. Recognition scheduling

The recognition campaign carried out has been proposed by the drafting team of the works project, in order to obtain sufficient knowledge of the geotechnical characteristics of the land with reasonable certainty.

Based on the above, a campaign was proposed consisting of:

4 mechanical rotary boreholes, 6 and 20 m deep.

4 soil pits.

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2. GROUND RECOGNITION

2.1. RECOGNITION WORKS CARRIED OUT

The terrain reconnaissance work carried out is summarized in the following table:

BOREHOLES

Nº

Perforated length (m)

Soils Gravels Rocks Total

4 38,20 1,00 - 39,20

SOIL PITS Nº 4 Samples 4

OTHER FIELD

TESTS

SPT Unaltered samples Paraffinized witnesses Water samples Piezometric tubing

13 11 - 1 21,00

They have been essentially established in the previous offer, with the following relevant modifications:

Increased depth of borehole S-2 to check the geotechnical characteristics of the existing substrate at depth.

All of them have been coordinated and supervised by specialized technical staff from

ELABORA.

It should be mentioned that notwithstanding the representativeness of the recognitions supported by the design of the campaign and the experience of the writing team of this report, the results collected in it correspond to specific investigations carried out at a certain time. For this reason, irregularities or non-systematic heterogeneities cannot be ruled out, the detection of which would far exceed the scope of the this work.

2.1.1. Boreholes

FOUR mechanical rotary boreholes have been made with the following denomination and depth:

NAME DEPTH (m)

S-1 6,05

S-2 21,05

S-3 6,05

S-4 6,05

The continuous witnesses extracted from the surveys have been collected in THIRTEEN

BOXES arranged for this purpose for their witnessing and conservation.

Boreholes are perforations of variable diameters and depths that allow to recognize the nature and location of the different geotechnical units of the terrain, as well as to extract samples from it and, where appropriate, to carry out tests at different depths. They allow:

Reach depths greater than those achievable with soil pits.

Recognize the terrain below the water table.

Drill rocky or high resistance layers.

Extract deep undisturbed samples.

Carry out pressure-gauge, pinwheel, standard penetration, etc. deformability or resistance tests.

Take samples from deep aquifers or perform permeability tests on site.

Determine rock index values in rock masses.

Detect and control variations in the water table, by the installation of piezometric tubes.

Rotational drilling, using single, double or special batteries can be used on any type of terrain, being necessary to use them when the terrain to be surveyed is a rocky massif or there is an alternation of hard cemented layers with other less cemented ones. In its use, it must be taken into account that there may be problems in the recognition of fine granular soils below the water table and in that of boluses or coarse gravels. Cores extracted from collapsible soils under the action of injection water and those from soft sandstone-type rocks that can become excessively fragmented by the effect of rotation must also be interpreted with care.

The boreholes in this report have been carried out with a TECOINSA TP-50/400 probe on a truck. The perforation has been made with a minimum diameter of 86 mm.

2.1.2. Soil pits

FOUR pits have been made with the following denomination and depth:

P-1 2,60

P-2 2,40

P-3 2,60

P-4 2,60

Soil pits are understood as excavations of various shapes (wells, trenches, chases, etc.) that allow direct observation of the terrain, as well as taking samples and eventually conducting tests on site. This type of recognition is recommended in cases of:

Moderate depth of recognition (<4m).

Grounds that can be excavated with a mechanical shovel or manually.

Absence of groundwater level in the recognized depth or when there are moderate contributions of water in low permeability lands.

Preferably cohesive grounds.

Granular soils where small diameter holes would not be representative

Land survey using pits is especially suitable when:

The firm or resistant layer can be reached at all points with sufficient guarantee.

is not necessary to carry out on-site tests associated with boreholes (e.g. standard tests).

This possibility is excluded when the ground of support can be deteriorated with the excavation and affect future foundations or create instability problems for nearby structures.

On the walls of the excavated ground, tests can be carried out on site, such as the pocket penetrometer, in order to obtain an indicative indication of the behavior of the ground, although they are not used to deduce, in any case, quantitative values of the resistance of the ground.

2.1.3. Other field tests

2.1.3.1. Standard penetration test within a borehole

THIRTEEN drilling penetration tests (S.P.T.) have been carried out at different depths, as follows:

BOREHOLE S-1

3,60 – 4,05 5,60 – 6,05

BOREHOLE S-2

1,60 – 2,05 3,60 – 4,05 6,60 – 7,05 9,60 – 10,05

12,00 – 12,45 15,00 – 15,45 20,60 – 21,05

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BOREHOLE S-3

3,60 – 4,05 5,60 – 6,05

BOREHOLE S-4

3,60 – 4,05 5,60 – 6,05

The standard penetration test or S.P.T. it is a discontinuous penetration test that is carried out inside a borehole. It is regulated by the UNE 103800 standard and provides an indirect measure of the resistance of floors. It is apt to report on:

The compactness of granular soils: relative density and angle of internal friction.

The strength of preconsolidated clays above the water table.

The measurement directly obtained from the test indicates the number of strokes (N) required to drive 30 cm of a hollow cylinder of standard dimensions by striking a 63.5 kg hammer falling from 76 cm.

In the case of clean granular soils without cohesion, it is possible to estimate their friction angle based on the SPT according to the following table, contained in the Basic Document SE-C “Foundations”:

In the case of clayey soils, the following indicative consistency values can be adopted with due precautions:

N < 2 2 - 4 4 - 8 8 - 15 15 - 30 > 30

Consistency Very soft Soft Medium Firm Very firm Hard

Compressive strength, qu (kPa) 25 25-50 50-100 100-200 200-400 >400

In this survey, the tests have been carried out with an automatic penetrometer incorporated into the TECOINSA brand probing equipment.

RELACIÓN ENTRE EL ÁNGULO DE ROZAMIENTO Y EL GOLPEO SPT

28 30 32 34 36 38 40 42 44

ÁNGULO DE ROZAMIENTO INTERNO

G O

L P E O

S P T

MEDIANAMENTE DENSO DENSO MUY DENSOSUELTO

MUY

SUEL

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2.1.4. Water table investigation

The depth of the water level has been measured in each of the soundings carried out once they were completed. Likewise, piezometric tubes have been installed inside the perforations to allow the monitoring of obtained level over time.

In the same way, representative samples of the detected water have been taken to investigate its possible aggressiveness to the foundation materials. The summary of the measurements carried out in these aspects is shown in the following table:

BOREHOLE NAME WATER SAMPLE PIEZOMETRIC TUBE LENGHT(m)

S-2 SI 21,00

With regard to the water table values obtained, where appropriate, the following precautions must be indicated

Since the mechanical soundings have been carried out with the help of water, this may have influenced the level obtained.

Therefore, for a correct mesurement of the level it is necessary to monitor its evolution over time, in order to eliminate the aforementioned influence.

In addition, the perforation mouth must be protected by means of a sealing box or plug that prevents the entry of water into the perforation.

When interpreting the level, it is also necessary to consider the possibility of external influence effects, which could indicate a false level: hanging water, leaks from supply networks, tides, etc.

2.1.5. Sampling

Samples have been obtained from the field survey work to perform the pertinent laboratory tests on them with sufficient reliability according to the determinations sought.

Specifically, the following samples have been extracted at different depths, as follows:

BOREHOLES DENOMINACION DEPTH

(m) PROCEDURE CATEGORY

DRILLING

SAMPLE DEPTH

(cm)

S-1

MI-1

MI-2

3,00 5,00

Percussion Percussion

A A

S-2

MI-1

MI-2

MI-3

MI-4

MI-5

1,00 3,00 6,00 9,00

18,00

Percussion Percussion Percussion Percussion Percussion

A A A A A

S-3

MI-1

MI-2

3,00 5,00

Percussion Percussion

A A

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BOREHOLES DENOMINACION DEPTH

(m) PROCEDURE CATEGORY

DRILLING

SAMPLE DEPTH

(cm)

S-4

MI-1

MI-2

3,00 5,00

Percussion Percussion

A A

MI: Muestra inalterada (Unaltered sample) --: Couldn´t be extracted.

Depending on the collection process, there are three types of samples can be identified, taking into account the classification contained in the Basic Document SE-C “Foundations”, which determine the types of tests that can be applied to them

Category A samples: are those that maintain the following soil properties unchanged: structure, density, humidity, granulometry, plasticity and stable chemical components. This is the case of those identified in this report as “undisturbed samples” (MI). To obtain it, it is necessary to use samplers with standard dimensions according to the following table:

Category B samples: are those that maintain the following soil properties unchanged: moisture, granulometry, plasticity and stable chemical components. The so-called “paraffinized cores” (TP) are included here.

Category C samples: are all samples that do not meet category B specifications, known as “altered samples” (MA).

2.1.6. Laboratory tests

On the samples taken in the field, laboratory tests have been carried out to know the identification characteristics, state, resistance, deformability and composition of the materials traversed, as well as the aggressiveness of the water detected.

The total number of tests carried out is summarized in the following table:

DETERMINACION BOREHOLES SOIL PITS TOTAL

Granulometry 7 2 9

Atterberg limits 7 2 9

Specific weight 5 - 5

Natural humidity 5 - 5

Normal proctor - 2 2

CBR - 2 2

Simple compresion 5 - 5

Free swelling 2 - 2

Swelling pressure 2 - 2

Direct cutting CU 2 - 2

Sulfate ion 5 - 5

Baumann-Gully 2 - 2

Water aggressiveness 1 - 1

The standards that regulate the performance of the aforementioned tests are those listed in the following

2.2. DISTRIBUCION OF GEOTECHNICAL UNITS

Based on the criteria of lithological nature, identification and mechanical behavior, it is possible to differentiate the materials detected in the surveys in a series of relatively homogeneous levels. This separation is in turn contrasted with the results of continuous penetration tests.

The identified units are described below, sequentially from the current grade of the plot.

2.2.1. Geotechnical units detected

In the surveys carried out, the following formations have been detected up to the depth reached.

LEVEL 1: Current fill Its presence has been detected in all surveys with the following characteristic thicknesses:

We classify as filling the surface area made by man, whether it is limestone gravel, silty sand type albero or silty clay with rock fragments. We also included road fill / topsoil, described as dark brown clay with the presence of roots and intense bioturbation.

LEVEL 2: Dark brown clay Under the previous level, this second formation appears in all the reconnaissance at the following depths:

Prospección Techo Base Potencia

Sondeo S-1 0,00 0,80 0,80

Sondeo S-2 0,00 0,40 0,40

Sondeo S-3 0,00 1,00 1,00

Sondeo S-4 0,00 0,80 0,80

Cata P-1 0,00 1,30 1,30

Cata P-2 0,00 0,30 0,30

Cata P-3 0,00 1,10 1,10

Cata P-4 0,00 0,50 0,50

Profundidad detectada (m)

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The material is described as dark brown clay with traces of sand, black mottling and traces of current bioturbation, fine roots, and fragments of current bioclasts. The consistency of this level is medium.

LEVEL 3: Brown clay with presence of carbonates In the boreholes this level has been detected with the following representative thicknesses:

It is a brown clay with nodules and whitish carbonate lenses. It may have dark gray streaks and black mottling.

LEVEL 4: Alternation of clays and sands Finally, the S-2 borehole was extended to obtain deeper information on the substrate in the area. In this borehole an alternation of clay and sand levels is observed, in which the clay thickness decreases, and from 18.00 m and until the end of the borehole at 21.00 m there is a yellowish silty sand somewhat cemented to sandstone.

Prospección Techo Base Potencia

Sondeo S-1 0,80 2,10 1,30

Sondeo S-2 0,40 4,90 4,50

Sondeo S-3 1,00 2,20 1,20

Sondeo S-4 0,80 2,40 1,60

Cata P-1 1,30 2,60 1,30

Cata P-2 0,30 2,40 2,10

Cata P-3 1,10 2,60 1,50

Cata P-4 0,50 2,60 2,10

Profundidad detectada (m)

Prospección Techo Base Potencia

Sondeo S-1 2,10 6,05 3,95

Sondeo S-2 4,90 6,30 1,40

Sondeo S-3 2,20 6,05 3,85

Sondeo S-4 2,40 6,05 3,65

Profundidad detectada (m)

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The last three meters of the borehole clearly belong to the Miocene substrate of the study area.

2.2.2. Water table

The presence of water has been detected at the following depths in the surveys carried out:

BOREHOLE MESUREMENT DATE WATER DEPTH

S-1 9/10/2020 Not present

S-2 (PVC) 9/10/2020 6,00 m

S-3 8/10/2020 Not present

S-4 8/10/2020 Not present

However, it must be emphasized, as mentioned in the previous sections, that the levels detected can only be associated with the water table if its stability over time is verified, once the disturbing factors caused by drilling have been eliminated, both the waterproofing of the walls such as the use of refrigerant or containment fluid, and that there is no different external source, such as leaks from urban supply networks, etc.

In the present case, due to the temporary limitation of the execution period of the works, no follow-up has been carried out in time to verify the mentioned stability, and for information purposes, the date of the measurement performed is included in the table above.

2.3. SITUATION OF THE RECOGNITION POINTS

The location of the survey points has been established by the project's writing team, taking into account the characteristic location that is better documented in the corresponding annex and is summarized below:

- In this sense, a short borehole has been located next to each of the houses and two boreholes in the eastern part of the plots.

- The soil pits have also been located two of them next to the houses and two in the east of them.

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2.4. GEOTECHNICAL CHARACTERISTICS OF THE LAND

For each of the geotechnical units detected, the characteristic values of its parameters are identified below, deduced from the basis of tests and onsite tests.

From the results of the laboratory tests carried out on the extracted samples, the main characteristics from the geotechnical point of view of the materials traversed are obtained, which are summarized in the following tables:

RECONOCIMIENTO S-2 P-1 P-3 S-1 S-1 S-2 S-3 S-3 S-4

MUESTRA MI-1 MA MA MI-1 MI-2 MI-3 MI-1 MI-2 MI-1

TIPO A C C A A A A A A

PROFUNDIDAD (m) 1,00-1,60 1,50-1,70 1,50-1,70 3,00-3,60 5,00-5,60 6,00-6,60 3,00-3,60 5,00-5,60 3,00-3,60

NIVEL GEOTÉCNICO

% pasa tamiz 5 mm 100 100 100 96 100 99 100 100 95 % pasa tamiz 0,08 mm 82 73 92 66 80 84 77 82 50

Límite líquido 35,4 30,3 34,4 44,7 35,3 49,3 25,0 29,1 26,9 Límite plástico 15,6 12,7 16,4 19,0 16,0 19,6 12,5 14,5 12,1

Índice plasticidad 19,7 17,5 18,0 25,7 19,3 30,0 12,5 14,6 14,9

13,1 15,7 18,5 17,4 9,6 20,7 21,3 22,5 22,0 19,0

44 246 28 104 24 Cohesión cu (kPa) 134,4 6,9

Ángulo rozamiento ɸu (º) 15,2 35,6

1,45 1,50 24,5 19,6

PRÓCTOR 1,69 1,68

NORMAL 19,4 19,2

2,2 3,1 0,4 0,6

181,9 211,6 200,9 176,2 189,3 0 0

CL CL CL CL CL CL CL CL CL

IDENTIFICACIÓN

CU

ESTADO

RESISTENCIA

2 3

Granulometría

Peso específico aparente, g (KN/m3)

Ión Sulfato (mg/kg) Acidez Baumann-Gully (ml/kg)

Humedad óptima (%)

Humedad natural, w(%)

Resistencia compresión simple, qu (kPa)

Presión de hinchamiento (kPa) Hinchamiento libre (%)

Plasticidad

Índice al 95 % P.N.

Hinchamiento (%)

CLASIFICACIÓN

CONTENIDO QUÍMICO

Corte Directo

CAMBIO DE VOLUMEN

C.B.R.

COMPACTACIÓN

Dens. máxima (kN/m3)

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LEVEL 1.- Current fill: no laboratory tests have been carried out on samples of this level given their limited thickness and their little, or almost no, participation in the design of future foundations.

LEVEL 2.- Dark Brown clay: samples corresponding to this level are generally identified as clay of medium plasticity with variable sand content. The proportion of fines smaller than 0.08 mm is on average 82%. The liquid limit ranges from 30 to 35, with the plasticity index from 17 to

19. It is classified according to the USCS as CL.

They have a humidity of 13.1% and an apparent specific weight of 20.7 kN / m3.

A simple compression test has been carried out, from which a resistance of 44 kPa is deduced. From the onsite tests a representative NSPT of 26 is obtained, which indicates a medium consistency.

In the free swelling test, a result of 1.45% and a swelling pressure of 25 kPa are obtained.

In order to calibrate this uncertainty, it is usually resorted to complementing the expansive assessment by indirect methods, in relation to other parameters. Applying these methods, the following estimate is deduced from the investigated materials:

Benchmark

EXPANSIVITY SCORE

LOW MEDIUM HIGH VERY HIGH

Plasticity index <15 15–25 25-35 >35

Liquid limit <30 30-40 40-60 >60

% passes sieve 0.08 mm <30 30-60 60-95 >95

Humidity Liquid limit >0,55 0,55-0,37 0,37-0,25 <0,25

Humidity Plastic limit >1,0 1,0-0,8 0,8-0,6 <0,6

Swelling pressure (kPa) <25 25-125 125-300 >300

Free swelling (%) 0,0-1,0 1,0-4,0 4,0-10,0 >10,0

This analysis shows that, despite the relative quantification obtained in direct tests, there is an expansive potential that can be classified as a medium closely related to the state of the material and, especially, to its humidity.

In the compaction tests, values of maximum normal protrusion density of 1.68 Tm / m3 are obtained with optimum humidities that vary between 19.3%. In the CBR test, CBR indices are obtained at 95% of the maximum normal proctor density of between 2.2 and 3.1.

In the chemical characterization tests, a sulfate ion content of 181 mg / Kg and a Baumann-Gully acidity result of 0 ml / kg were obtained.

LEVEL 3.- Brown clay with carbonates: six samples from the boreholes have been analyzed at different depths that are identified as clay of medium plasticity with variable sand content, from clay with some sand to sandy clay. The proportion of fines smaller than 0.08 mm is on average 73%. The liquid limit ranges between 25 and 49, with the plasticity index varying between 12.5 and 30. All samples are classified according to the USCS as CL.

They have an average humidity of 15.3% and an average apparent specific weight of

21.2 kN / m3, with a minimum value of 19 kN / m3 and a maximum of 22.5 kN / m3.

Four simple compression tests have been carried out from which a mean compressive strength of 100 kPa is deduced. It must be taken into account that the sand content makes the soils more fragile and crumblier, resulting in two excessively low values of around 25 kPa.

Two direct consolidated cuts have been made without drainage, from which two very different cohesions and friction angles are obtained, in accordance with the sand content of the samples.

In the onsite tests, an NSPT is always higher than 15, with a mean NSPT value of 35, which generally indicates a firm to very firm consistency.

In the free swelling test, a result of 1.50% and a swelling pressure of 20 kPa has been obtained.

To calibrate this uncertainty, it is usually resorted to complementing the expansivity assessment by indirect methods, in relation to other parameters. Applying these methods, the following estimate is deduced from the investigated materials:

Benchmark

EXPANSIVITY SCORE

LOW MEDIUM HIGH VERY HIGH

Plasticity index <15 15–25 25-35 >35

Liquid limit <30 30-40 40-60 >60

% passes sieve 0,08 mm <30 30-60 60-95 >95

Humidity Liquid limit >0,55 0,55-0,37 0,37-0,25 <0,25

Humidity Plastic limit >1,0 1,0-0,8 0,8-0,6 <0,6

Swelling pressure (kPa) <25 25-125 125-300 >300

Free swelling (%) 0,0-1,0 1,0-4,0 4,0-10,0 >10,0

This analysis shows that, despite the relative quantification obtained in direct tests, there is an expansive potential that can be classified as medium-high, closely related to the state of the material and, especially, its humidity.

In the chemical characterization tests, an average sulfate ion content of 194 mg / Kg and a Baumann-Gully acidity result of 0 ml / kg were obtained.

2.4.1. Excavability

From the construction of the soil pits with a mixed backhoe, it can be concluded that all the formations detected on the surface are easily excavatable, having reached the desired depth in the surveys.

2.4.2. Stability of the soil pit wall

The execution of the soil pits, although they are shallow holes of small dimension and of short duration, can illustrate to some extent the stability of the materials detected in the short term. This is especially interesting for the planning of possible temporary excavations in trenches, holes, etc.

The pits have remained stable during their excavation with no significant dislodges or movements. This conclusion can be applied to the formations involved, corresponding to levels 1 and 2.

2.5. SEISMIC CHARACTERIZATION OF THE LAND

According to the NCSR-02 Earthquake Resistant Construction Standard, the construction under study can be characterized from the average thicknesses detected at each level by the following parameters:

TECHO BASE

1 0,00 0,80 0,80 IV 2,0

2 0,80 2,90 2,10 III 1,6

3 2,90 6,30 3,40 II 1,3

4 6,30 30,00 23,70 II 1,3

1,34

(*) NOTA:

NORMAL ESPECIAL

1,0 1,3

1,072 1,072

0,064 0,084

COEFICIENTE AMPLIFICACIÓN DEL TERRENO, S

ACELERACIÓN SÍSMICA DE CÁLCULO

PROVINCIA SEVILLA

LOCALIDAD

ACELERACIÓN BÁSICA, ag

ARAHAL

0,06

IMPORTANCIA DE LA CONSTRUCCIÓN

COEFICIENTE ADIMENSIONAL DE RIESGO, r

Se ha supuesto la prolongación del último nivel detectado hasta la profundidad de 30 m bajo la superficie que marca la NCSR-02

ESPESOR TIPO DE

TERRENO

COEFICIENTE

C

COEFICIENTE DEL TERRENO, C

NIVEL

PROFUNDIDAD

EXAMPLE ONLY

The classification of land included in NCSE-02 responds to the following criteria:

Type I: compact rock, very dense cemented or granular soil.

Type II: very fractured rock, dense granular soils or hard cohesive soils.

Type III: granular soil of medium compactness, or cohesive soil of firm to very firm consistency.

Type IV: loose granular soil, or soft cohesive soil.

Similarly, it should be noted that as specified in NCSE-02, in buildings with basements below the general level of the ground surface, the thicknesses of the different layers to classify the foundation conditions should, normally, be measured from the ground level

2.6. WATER CARACTERISTICS

From the aggressiveness tests carried out on the water sample taken inside the borehole, the following characteristic parameters have been obtained:

PARAMETERS S-1

pH 7,83

Dry residue (mg/l) 400

Sulfates (mg/l) 134,0

Magnesium (mg/l) 88,0

CO2 (mg/l) 0,0

Ammonium (mg/l) 0,2

DEGREE OF AGGRESSEVENESS Not aggressive

The classification of chemical aggressiveness as stated in article 8.2 of the EHE Structural Concrete

Instruction allows identifying the "type of environment" to which a structural concrete is going to be subjected. This is defined by the set of physical and chemical conditions to which it is exposed and that can cause its degradation.

Apart from the processes linked to the corrosion of the reinforcement, which condition the so-called “general classes of exposure”, the EHE establishes another series of specific classes of exposure. In particular, those related to structures subjected to chemical attack (class Q), are classified according to the following criteria:

AGRRESSIVE

MEDIA TYPE PARAMETERS

TYPE OF EXPOSURE

Qa Qb Qc

WEAK ATTACK MEDIUM ATTACK STRONG

ATTACK

WATER

pH 6,5 - 5,5 5,5 – 4,5 < 4,5

Aggressive CO2 (mg/l) 15 – 40 40 – 100 > 100

Ammonium ion (mg/l) 15 – 30 30 – 60 > 60

Magnesium ion (mg/l) 300 – 1.000 1.000 – 3.000 > 3.000

Sulfate ion (mg/l) 200 – 600 600 – 3.000 > 3.000

Dry resedue (mg/l) 75 – 150 50 – 75 < 50

GROUND

Degree of acidity Baumann-Gully > 200 (*) (*)

Sulfate ion (mg/kg suelo) 2.000 – 3.000 3.000 – 12.000 > 12.000

(*) These conditions do not exist in practice.

EXAMPLE ONLY

3. FOUNDATION SOLUTIONS

A series of proposals for the foundations have been described from the point of view of the information obtained in the geotechnical reconnaissance campaigns.

It should be noted that these are simply indicative proposals based on the lithology and parameters obtained, although a series of quantitative data (sinking loads, settlements, etc.) are included strictly valid for the predimensioning of the mentioned elements since their obtaining is based on simplified assumptions and ranges of usual loads on the geometries described by the client.

In any case, the best estimate of the definitive geotechnical verification parameters requires a complete definition of the geometry of the works, the type of loads, and the support and grade levels.

3.1. ANALYSIS OF THE GEOTECHNICAL PROBLEMS RAISED

In view of the morphology of the plots to be surveyed, the lithologies detected, the properties of the materials and the proposed construction typology, it should be mentioned that the main problems must be taken into account for the purposes of their design and construction:

Presence of the phreatic level detected at a depth of 6.00 m.

Average expansivity of the materials detected in the upper zone that can be included in the active layer.

3.2. PROPOSED FOUNDATION TYPES

According to the typology of the constructions to be carried out and the indications of the drafting team of the project, a footing over shaft foundation is initially considered viable as a direct foundation solution.

The foundation level must exceed the thickness of the active layer of the ground in which changes in volume occur due to the change in humidity of the ground. The thickness of the active layer in Andalusia is established at about 3.00 m thick.

Next, as a recommendation, the sinking load values that can be estimated for this type of foundation are established based on the results obtained from the investigations carried out. It should be mentioned that the following indications must be contrasted with the typology, dimensions and actual construction process of the works, as well as with the existing conditions on the land at the time of construction.

In the same way, it should be mentioned that additional issues of global stability, sliding, overturning, influence on adjacent buildings, subsidence, negative friction, etc., clearly exceed its scope, as well as the structural issues of the elements of the foundation.

3.3. DIRECT FOUNDATION THROUGH INSULATED ELEMENTS

3.3.1. Simplified allowable load for direct foundations

Due to the limitation of the information obtained by the conditions already exposed, it is only possible to deduce an approximate reference value for the admissible load to be considered in the design of the proposed foundations.

Thus, assuming the only condition of the clay material detected by the pressure bulb of the future foundations, and understanding that when dealing with fine soils the critical design situation corresponds to the so-called "short term" or "no drainage" load. The vertical load subsidence of a square direct foundation in a horizontal terrain, can be estimated under these hypotheses applying the calculation methods established in the Basic Document SE-C “Foundations”. As:

Where:

qh is the sinking load cu is the shear strength without drainage, which in the present case can be estimated as 50 kPa (½ of the simple compressive strength).

sc is a coefficient that considers the shape of the foundation that varies between:

1,0 for running footing 1,2 for square footing dc is a depth coefficient that in the present case of an implantation at more than 3 m, it adopts a value equal to 1.3.

qo is the value of the weight of earth or perimeter overload to the footing, neglected in this case.

With this, the sinking load obtained will be:

It can be verified that initially the value obtained for the simplified hypotheses presented does not depend on the dimensions of the footings.

The admissible load for the purposes of the design of the foundations is deducted from the sinking load, affecting this by the safety coefficient established in the Basic Document SE-C “Foundations” of the Technical Building Code according to the following table:

EXAMPLE ONLY

For the specific case of the foundation studied in the "no drainage" or short-term situation, it is possible to deduce based on the above a summary, the admissible loads under the proposal of applying the following safety factors:

R = 3,0 for de cohesion term

R = 1,0 for the overload term With this, the value of the admissible load is obtained:

3.3.2. Direct foundation settlement

In the case of the direct foundation mentioned above, it is necessary to verify the settlement that occurs in the ground. This value, depending on the type of structure and terrain on which the construction is located, can sometimes condition the maximum load to be transmitted.

The usual limitations for the maximum settlement are of the type set forth in the NBE- AE-88 norm on Actions in Building, as follows:

BUILDING TYPE

MAXIMUM SEAT (MM)

SANDS CLAYS

Monumental works 12 25

Highly rigid reinforced concrete buildings 35 50

Flexible reinforced concrete buildings Hyperstatic metal structures Buildings with masonry walls

50 75

Isostatic metal structures Wooden structures

Provisional structures >50 >75

For its part, the Spanish standard UNE-EN 1997-1 June 2016 “Eurocode 7:

Geotechnical project. Part 1: General rules”, in its Annex H, “Limit values of structural deformations and movements in foundations”, establishes the following for structures in habitual use:

For normal structures with isolated foundations, total settlements of up to 50 mm are normally allowed. Larger seats can be admitted as long as the relative rotations are kept within tolerable limits, and that the total seats do not pose problems with the services that attack the structure; or produce inclinations, etc.

The simplified estimation of the maximum settlement under a rigid square load on a homogeneous ground assuming an elastic behavior of the ground, can be obtained from the following expression:

E25,1 1LBqs

Where:

q is the mean pressure transmitted by the footing.

B y L are the dimensions from plant.

E is the Young module of the ground.

is the Poisson coefficient of the ground.

For the estimation of the elastic parameters of the soil, the use of the guideline values collected in the Basic Document SE-C “Foundations” of the Technical Building Code is proposed.

EXAMPLE ONLY

From it the following proposed values can be deduced:

E ≈ 8 MPa

≈ 0,30 Applying this method, it is obtained that for the proposed admissible load of 133 kPa the seat reached, in this case dependent on the size of the foundation, is:

WIDTH (m) LENGTH (m) SEATING (cm)

1,0 1,0 1,2

1,5 1,5 1,8

2,0 2,0 2,4

These values are ALLOWABLE based on the above limitations.

3.3.3. Other geotechnical parameters

For the adoption of the rest of the parameters that weren’t deduced from the tests carried out, it is proposed to use the guideline values contained in the Basic Document SE-C "Foundations" of the Technical Building Code and in the Geotechnical Recommendations for Maritime and Port Works ROM 0.5-05, which are extracted in the following tables, respectively:

These same values can be considered for the calculation of uncontained slopes and excavations to be carried out on the plot under study.

Finally, it is necessary to remember the importance of considering the water table in this type of verification.

However, in the previous proposals, it is necessary to insist that the parameters that have been deduced directly or indirectly from the characterizations and tests carried out should be suitably corrected (reduced, statistically treated, etc.) for the selection and final determination of the values representative for sizing. Based on them, the characteristic values can be obtained, a task that must be carried out by the designer depending on the confidence in obtaining the parameters (number of tests, type of test, conditions, etc.) and the sensitivity of the work.

to be projected in the calculations of each of the parameters.

3.4. SOIL PERMEABILITY

In the case that the support of the last floor below ground is projected below the water table, for the purpose of fulfilling the waterproof characteristics included in the Basic Health Document DB-HS, it is necessary to consider the degree of impermeability required.

For these purposes, it is recommended to adopt the standard permeability values characteristic of each of the levels described, adopted from among those recommended by the Technical Code itself, according to the following table:

These values together, with the exposure to water deduced from the proximity of the phreatic level, will determine the degree of impermeability required according to the following

The presence of water is classified, according to the relative position of the face of the soil in contact with the ground and the water table, as follows:

Low: The underside of the soil is above the water table.

Medium: The underside of the soil is at the same depth as the water table or less than two meters below.

High: The underside of the soil is ≥ 2 m below the water table.

EXAMPLE ONLY

In this case, the support level of the foundation has been foreseen on geotechnical level 3, characterized as brown clay with carbonates, so it can be assigned a permeability coefficient lower than 10-5 cm / s. Consequently, the recommended degree of impermeability for floors is 1.

Based on these parameters, and as established in section 2.1.2 Conditions of the DB- HS construction solutions, the conditions required for each construction solution, depending on the type of wall, the type of waterproof and the degree of impermeability, are obtained in table

2.2. attached. In which the shaded boxes refer to solutions that are not considered acceptable and the blank box to a solution for which no conditions are required for the corresponding degrees of impermeability:

The aforementioned section of the DB-HS collects in detail the meaning of the proposed construction solutions.

3.5. SPECIFIC CONSIDERATIONS IN EXPANSIVE SOILS

Given the presence in the upper strata of the ground of potentially expansive materials, and their location in the "active layer", they are susceptible to modifying their humidity state.

That is why the following precautions must be specially recommended:

Excavations will be kept open for as little time as possible and must never be affected by flooding or rain, as well as avoiding weathering due to desiccation.

The foundation pits or footings and brace beams will be laterally shuttered, in order to reduce friction between the ground and the walls.

EXAMPLE ONLY

In the urbanization project and other elements attached to the building, it should be sought to avoid the possible infiltration of runoff, rainwater or irrigation water into the land.

Large plantations will not be available in the vicinity of the buildings.

All water conduction systems (drainage, irrigation, sewerage and sanitation) will be sufficiently flexible and watertight to avoid that, due to possible movements of the ground, it creates breakage and generates leaks or seepage into the ground.

If possible, the area adjacent to the buildings will be paved with materials that ensure waterproofing in a width of not less than two meters.

In addition, the paving of the building constructions will be made independent, by means of joints. Preventing a "hanging" effect from sidewalks, stairs, etc., from other more rigid structures with completely different loads and deformations.

These recommendations are not mentioned exhaustively, but must be complemented with the rest of the usual good practice construction provisions in this type of terrain. An annex is included with a listing of some of these recommendations.

4. SUMMARY AND CONCLUSIONS

As a summary of all the points collected in the previous sections, the conclusions are extracted in the following table:

GEOTECHNICAL REPORT SUMMARY SHEET

FOUNDATION TYPE Footing over shaft foundation

SUPPORT LEVEL

Geotechnical level 3.- Brown clay with carbonates

Estimated depth ≥3 m

ALLOWABLE PRESSURE

(FOOTING FOUNDATION)

1,0*1,0 m 1,5*1,5 m 2,0*2,0 m

133 kPa

MAXIMUM SEATING OBTAINED 1,2 cm 1,8 cm 2,4 cm

WATERTABLE

Depth 6,00 m (S-2)

Follow-up No

GROUND AGGRESSIVENESS

LEVEL Sulfate ion (mg/Kg)

Baumann-Gully acidity (ml/kg)

2 181 0

3 194 0

WATER AGGRESSEVNESS Not Aggressive

EXPANSIVITY 2 y 3 Medium

SEISMIC ACCELERATION

Importance Normal Special

Acceleration 0,064 0,084

Due to the limited scope of this study, no data of land or water related to habitability or health aspects are included in this study.

It should be mentioned that all the data and calculations included in this report are deduced from occasional surveys carried out for this purpose according to the accepted criteria and current regulations. However, the fact that the surveys are punctual samples in time and space, makes it necessary to establish due precautions against possible irregularities, heterogeneities and variations that can be naturally detected in the materials analyzed, both in the subsoil and in the groundwater.

Therefore, at the beginning of the excavations and before proceeding to build the structure of the foundation, the competent technician must visually check, or by means of the tests they deem appropriate, that the support ground corresponds to the forecasts included here.

In the case of superficial foundations, it should be checked:

The stratigraphy coincides with that estimated in this Geotechnical Study.

The phreatic level and the hydrogeological conditions are in line with those foreseen in this study.

The resistance and humidity of the soil found at the foundation level coincide with those defined.

No obvious defects such as caves, faults, galleries, wells, etc. are detected.

No underground streams are detected that could produce scour or dragging.

Water and soil are not aggressive to the footing or slab materials

Seville, November 10, 2020

Fdo.: Ramón Romero Ortiz Fdo.: Rocío Ahumada Rivas Ingeniero de Caminos Geóloga

ANNEXES

This geotechnical study consists of a memory of 41 numbered pages accompanied by the following Annexes:

Annex 1: Location map of the reconnaissance.

Annex 2: Land survey report: field activities and laboratory tests.

EXAMPLE ONLY

ANNEX 1: SURVEY LOCATION PLAN

PLANO DE SITUACIÓN DE ENSAYOS GEOTÉCNICOS

Sondeos geotécnicos S-1

Calicatas P-1

EXAMPLE ONLY

ANNEX 2: SOIL SURVEY REPORT

BOREHOLE SURVEY AND PICTURES

TUBERIA PIEZOMETRICA:No MUESTRA DE AGUA:No SONDISTA: Jose Manuel Domínguez Moreno SONDA: Tecoinsa TP 50/400

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