1. An approach for improving Wesley Engineering Classification.
The case of Porto Granites
Nuno Cruz, Cristina Gomes, Carlos Rodrigues and Antonio Viana da Fonseca

2. 1. Introduction
Data analysis within a PhD program (Cruz, 2010) based on:
Porto Geotechnical Map (COBA 2003), which covers the urban area
Several sponsored research programs generated by construction for European Football Championship, European Capital of Culture and Metro do Porto network
High quality data from 3 PhD thesis ( Viana da Fonseca.1996; Rodrigues, 2003; Topa gomes, 2009)
Dataset available in MOTA-ENGIL and CICCOPN from their industrial activities
Mas e se…

3. 1. Introduction
All details of the analyisis may be found in PhD thesis (english)
nbdfcruz.drupalgardens.com

4. Compressive strength/ Deformability modulus Diametral compression
1. Introduction
Test designation
Number of tests
Grain size
290
Atterberg limts
220
Unit weight
172
Porosity 62
In-situ permeability
420
Compressive strength/ Deformability modulus
200
Diametral compression 70
Triaxial 68
SPT
15825
DPSH
688
Mechanical CPT
568
CPTu 22
PMT 75
DMT 36
Seismic refraction
198
Total number of tests
Mas e se…

5. 1. Introduction Designation Description W1 Unweathered rock W2
Slightly Weathered rock W3
Medium Weathered rock W4
Weathered rock W5
Decomposed rock G1
Dense soils (30<NSPT<60) G2
Medium Dense soils (10<NSPT<30) G3
Loose soils (NSPT<10)
Mas e se…

6. 2. Physical Evolution Increase with weathering of fine content
Unified Class: SM (W5, G1 and G2)
SC (G3)
Mas e se…

7. 2. Physical Evolution Main “jump” between W3 and W4
in situ coefficient of permeability
quite erratic in terms of evolution with weathering

8. Mechanical evolution through weathering (after Wesley, 1988).

9. 3. Mechanical Evolution Logarithmic decay
Main “jump” between W3 and W4
Logarithmic decay

10. 3. Mechanical Evolution
Linear decay
Linear decay

11. 3. Mechanical Evolution
Linear decay

12. 4. Wesley Classification
Group A: Soils without strong mineralogical influence;
A(a): Geomaterials in which macro-structure plays an important role in the engineering behavior (W4 and W5 massifs falling in this category)
A(b): Residual soils where macro-fabric no longer exists leaving the main control to micro-fabric (G1 to G3)
Group B: soils with a strong influence from clay minerals also found in transported soils;
Group C: Soils with a strong influence from clay minerals only found in residual soils.

13. 5. Proposed Sub-division (Cruz, 2010)
Sub-group A(a) is represented by NSPT higher than 60, identifying weathered to decomposed rock, where macro-fabric have a fundamental control
A(a1) – represented by NSPT>60 with penetration lower than 15 cm;
A(a2) – represented by NSPT>60 with penetration higher than 15 cm.
Sub-group A(b) is represented by NSPT lower than 60, identifying saprolites where microfabric controls the general behaviour. According to the presented database, this could be further divided in 3 categories:
A(b1) – represented by soils with 30<NSPT <60;
A(b2) – represented by soils with 10<NSPT <30;
A(b3) – represented by soil with NSPT<10.

14. 6. Index Parameter Ranges

15. 7. Conclusions
Evolution of mechanical properties is gradual and can be represented by more or less continuous rates.
The results arising from a wide range of tests showed high convergence between them and revealed that fundamentally weathering processes generate an increasing porosity and consequent mechanical degradation
Uniaxial compression strength, cohesion and deformability modulus reveal a logarithmic decay
Angles of shearing resistance decay at much lower rates, showing less influence in the general loss of strength.
The available data also made possible to confirm the adequacy of Wesley Classification in Porto and Guarda Granitic environments and to give an important contribution for the refinement of Group A of that classification

16. Thanks for your attention