UNITRACC - Underground Infrastructure Training and Competence Center

Hydrogeological fundamentals

Groundwater movement

Soil

The movement of free water in the in-situ subsoil that are caused, for instance, by gravitational forces or process measures occurs in the existing pore space.

(Image: Influencing variables of the soil - Mixed particle soils with air-filled pores, loose compactness)

Rock

In rock, it is not pores but discontinuities that form the hydraulically effective spaces.

(Image: Fissure cavaties in rock)

Sep 22, 2008

Hydrogeological fundamentals

Permeability of the soil

The measure for the permeability of the soil is the permeability coefficient k, also called k_w.

(Table: Permeability regions with reference to the permeability coefficient k to DIN 18130-1 [DIN18130-1])

Sep 22, 2008

Hydrogeological fundamentals

Sep 22, 2008

Definition rock

Rocks are mechanically resistant rock material, whose structure and deformability corresponds to that of solids [Chemi08].

ISO 14689 [DINENISO14689:2004] defines rock as, "a naturally occurring assemblage of minerals, consolidated, cemented or otherwise bonded together, so as to form material of generally greater strength or rigidity than soils".

The designation rock - opposite: soil - does not make a statement on the strength behaviour.

Rock:
A …

Sep 23, 2008

Rock is differentiated according to the mineral content and the history of its formation (rock material formation) as igneous rock material, sedimentary rock material and metamorphic rock material.
Igneous rock material is rock originating from the fluids inside the earth (e.g. granite or basalt).	Sedimentary rock material is formed from soil and the drainage of water and has been converted by pressure through consolidation (diagenesis) into, …

Sep 23, 2008

Definition discontinuities

Discontinuity:
A plane, which interrupts the contunity of the stone and can limit a fissure that is open or can open when stress changes (e.g. construction works) (with reference to [DINENISO14689-1:2004]).

(Image: Rock with bedding joints SF, bedding planes SS and fissure planes K1, K2, K3 to DIN 4022-1 [DIN4022])

Sep 23, 2008

Framework of discontinuities

A framework of discontinuities is understood to be the totality of all discontinuities occurring in rock. Type and origin, quantity, arrangement and formation of the discontinuities, together with the rock material properties characterize the rock mass properties [Ester95].

Discontinuities are described by:

spatial position
position
structure
clearance
level of discontinuity

Disadvantageous framework of dicontinuities at the example of shafts in …

Sep 23, 2008

Compressive strength

Since the compressive strength of a corpus depends on the experimental standard and does thus not represent a clear unit, the uniaxial compressive strength of a rock should always be determined by means of a uniaxial pressure test according to DIN 18316 [DIN18316].

The uniaxial compressive strength of rock can by estimated by means of field tests according to EN ISO 14689 [ [DINENISO14689-1:2004].

(Table: Field tests to estimate the uniaxial compressive …

Sep 22, 2008

Rock

Sep 23, 2008

Soil and rock classification related to trenchless installation

European standards for soil and rock classification in connection with trenchless installation

(Table: European standards for soil and rock classification in connection with trenchless installation of pipelines [FI-Steina])

Sep 23, 2008

Soil and rock classification related to trenchless installation

Soil and rock classification according to DIN 18300

In DIN 18300 "Contract procedures for building works - Part C: General technical specifications for building works; Earthworks" (ATV) [DIN18300-Cd], the subsoil is divided into seven soil and rock classes. The classification characteristic here is exclusively from the point of view of the ease of breakout .

Application range of DIN 18300:

in trenchless installation of pipelines it applies for the loosening, loading, conveying, installing and compacting …

Sep 23, 2008

Soil and rock classification related to trenchless installation

Soil and rock classification according to DIN 18300

(Table: Soil and rock classes to DIN 18300 [DIN18300-Cd])

Sep 23, 2008

Soil and rock classification related to trenchless installation

Soil and rock classification according to DIN 18319

The soil and rock types are first summarized into five main classes according to the material or soil and rock mechanical properties with reference to the technical requirements of boring and drilling works in trenchless installation .

Furthermore, it is distinguished between 12 soil classes and 8 rock classes as well as 4 additional classes for stones.

Application range of DIN 18319:

applies for underground installation of pre-fabricated pipes of …

Sep 23, 2008

Soil and rock classification related to trenchless installation

Soil and rock classification according to DIN 18319

(Image: Diagram of soil and rock classification in accordance with DIN 18319 [DIN18319])

Sep 23, 2008

Soil and rock classification related to trenchless installation

Soil and rock classes L (soil) according to 18319

(Table: Classes LN: Non-cohesive soil, particle size - 63 mm [DIN18319])

(Table: Classes LB: Cohesive soil, particle size - 63 mm [DIN18319])

(Table: Additional classes ("stone classes") S [DIN18319])

The class LO "organic soils", contains no further subdivisions.

Sep 23, 2008

Soil and rock classification related to trenchless installation

Soil and rock classes F (rock) according to DIN 18319

(Table: Classes F: Rock material [DIN18319])

Sep 23, 2008

Soil and rock classification related to trenchless installation

Unified Soil Classification System (USCS)

(Table: Soil classification according to the USCS (USA) [ASTMD248700])

Sep 23, 2008

Soil and rock classification related to trenchless installation

Rock classification - Rock Quality Designation Index (RQD-value)

The Rock Quality Index (abbreviated to RQD-value or RQD-index) was developed in 1967 by Deere [Deere67] as a characteristic for describing rock and relies on the length of the intact segments of the bore core to designate the quality of the rock mass.

The RQD-value provides the relationship L₁₀/L in percent where L₁₀ is the cumulative length of core pieces with intact length of 10 cm or more and L is the total length of the core.

(Table: Allocation …

Sep 23, 2008

Soil and rock classification related to trenchless installation

Classification according to the steerability

(Table: Classification of different types of soils according to steerability)

Sep 23, 2008

Soil and rock classification related to trenchless installation

Classification according to the stability at the working face

This classification proposal by Spang [Spang87] that can be used especially for pipe jacking with shield machines with partial excavation by hand (hand shields) or with mechanial partial excavation, is based on a classification system for tunnel construction in soil described in [Proct77].

(Table: Classification according to the working face behaviour)

Sep 23, 2008

Soil and rock classification related to trenchless installation

Classification according to the stability at the working face - classification

(Table: Classification according to the stability at the working face [Spang87])

Sep 24, 2008

Soil and rock classification related to trenchless installation

Soil and rock classification according to abrasiveness

The abrasiveness of a rock material is dependent on numerous parameters, among which are:

The content of abrasive minerals with a MOHS hardness > 5.5 (steel),
Fabric and texture,
Framework of discontinuities,
Effects of the change of the rock mass due to weathering.

[Thuro98b]

Sep 24, 2008

Soil and rock classification related to trenchless installation

Calssification of the abrasiveness with reference to the CAI Index

(Table: Classification of rock material with reference to the CAI index [Thuro98b])

(Table: CAI Index (Empirical values) for various types of rock material to Büchi [Büchi95])

Sep 22, 2008

Soil and rock classification related to trenchless installation

May 19, 2011