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Nov 20, 2006

Modules

Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 3: Adjustment and Replacement of Manhole Covers

Height levelling of manhole tops with removal

(Image: Distributing and smoothing the mortar) (Image: Placing the paving stones) (Image: Filling the joints)
(Image: Filled joints) (Image: Filling the remaining joints with the bituminous material) (Image: Newly installed manhole top with jointed paving stone surround)

Nov 20, 2006

Modules

Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 3: Adjustment and Replacement of Manhole Covers

Height levelling of manhole tops with removal

Bitumen joint strips serve to improve the connection between different materials, e.g. "splittmastix" and mastic asphalt and thus to prevent the formation of cracks and opening seams.

For conventional bitumen joint strips, an even edge is required as contact area [ZTVFugStB01]. The removal of the surrounding cover and carrier layer should be carried out by milling and boring. Before the joint strip is applied, the edge must be cleaned and pre-treated …

Nov 16, 2006

Modules

Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 3: Adjustment and Replacement of Manhole Covers

Nov 20, 2006

Modules

Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 3: Adjustment and Replacement of Manhole Covers

Rehabilitation failures

(Image: Unprofessional re-inclusion of the manhole top) (Image: Unprofessional re-inclusion of the manhole top)

Nov 20, 2006

Modules

Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 3: Adjustment and Replacement of Manhole Covers

Rehabilitation failures

(Image: Attention!)

One of the most frequent rehabilitation failures is the use of mortar systems of unsuitable compositions and/or their unprofessional application on the construction site.

The reason for this is that the different types of cement mortar applied in practice have significantly different material properties. This regards especially insufficient resistances to frost-dew changes and/or frost and thawing salts.

Possible sources of …

Nov 16, 2006

Modules

Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 3: Adjustment and Replacement of Manhole Covers

Nov 20, 2006

Modules

Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 3: Adjustment and Replacement of Manhole Covers

Quality assurance for prevention of rehabilitation failures

(Image: Documentation)

In order to prevent the mentioned weak points of the maintenance of manhole tops, the following measures are recommended:

  • realisation of suitability tests of rehabilitation processes,
  • consideration of suitable measures for quality assurance and suitability tests for the tender and award of contracts,
  • realisation of quality assurance measures in the rehabilitation process of manhole tops.

Nov 20, 2006

Modules

Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 3: Adjustment and Replacement of Manhole Covers

Quality assurance for prevention of rehabilitation failures


Another possibility to prevent rehabilitation failures is provided by the application of rehabilitation processes that have a strong resistance to dynamic loads and chemical/physical stresses.

Height levelling by means of:

  • plastic adjusting units
  • mastic asphalt inclusion
  • steel spring elements
  • separation of manhole top and manhole
(Image: Underfilling the frame of the manhole top with the aid of polyethylene equalising rings (ASD rings) …

Nov 20, 2006

Modules

Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 3: Adjustment and Replacement of Manhole Covers

Quality assurance for prevention of rehabilitation failures

(Image: Question)
  • Are the construction and rehabilitation costs proportionate to the service life?
  • Do seasonal climatic influences during the installation of the system and external impacts like dynamic traffic loads and sewer operations have any effects on the quality and the service life?
  • Is the quality of the system installation independent of the qualification of the installation personnel? Are suitable tests/controls required?
  • Is the system …

Nov 20, 2006

Modules

Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 3: Adjustment and Replacement of Manhole Covers

Quality assurance for prevention of rehabilitation failures

(Table: Measures of quality assurance for manhole rehabilitation [FI-Steina])

Nov 20, 2006

Modules

Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 3: Adjustment and Replacement of Manhole Covers

Quality assurance for prevention of rehabilitation failures

(Image: Documentation)

Suitability tests

It is recommended to apply only those rehabilitation processes that have been proved suitable by suitability tests. These must comprise in-situ laboratory tests of the applied materials as well as an investigation of the technology and processing of the materials.

Nov 20, 2006

Modules

Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 3: Adjustment and Replacement of Manhole Covers

Quality assurance for prevention of rehabilitation failures

(Image: Documentation)

Tender and award of contract

Within the scope of the tendering of rehabilitations of manhole tops, the measures of quality assurace and suitability tests of the processes should be part of the tender document. Such demands may be included e.g. in the so-called standard descriptions.

A skilled and experienced personnel is needed to evaluate the quality of the work during the realisation and supervision of the construction project. …

Nov 16, 2006

Modules

Repair of Concrete, Reinforced Concrete and Brick Manholes – Part 3: Adjustment and Replacement of Manhole Covers

Nov 16, 2006

Modules

Manholes perform a variety of functions, they are used to connect pipelines, to change direction and/or elevation, to provide access for personnel and/or equipment, and to provide aeration and ventilation to the drain and sewer system. Like sewers and pipes, defective manholes need to be repaired.

This module covers the regulation and replacement of manhole covers.

After completing this module, you will have a sound knowledge of:

  • damage and consequences of defective manhole covers;
  • variants of level regulation;
  • rehabilitation errors;
  • naming quality assurance measures and
  • developing rehabilitation proposals.

Jan 01, 1900

Modules

Trenchless 101 - Part VIII - Horizontal Directional Drilling

The lecture Horizontal directional drilling is part of the lecture series "Trenchless 101" and gives an introduction to the topic of HDD for the trenchless installation of supply and disposal lines.

Aug 15, 2006

Modules

Trenchless 101 - Part VIII - Horizontal Directional Drilling

Definitions

(Image: Unmanned techniques)
(Image: Steerable techniques)
(Image: Soil removal techniques)

In DIN EN 12889 [DINEN12889:2000] "Directional Drilling" is defined as: "A steerable system for the installation of pipelines using a drilling rig. A pilot bore is drilled using a steerable drilling head pushed by flexible rods. The bore is then enlarged by reamers up to the diameter required for the pipeline and then the pipe or pipes are pulled/pushed …

Aug 15, 2006

Modules

Trenchless 101 - Part VIII - Horizontal Directional Drilling

Definitions

(Image: Unmanned techniques)
(Image: Steerable techniques)
(Image: Soil removal techniques)

Directional Drilling (Horizontal Directional Drilling):
A steerable system for the installation of pipes, conduits and cables in a shallow arc using a surface launched drilling rig. Traditionally the term applies to large scale crossings in which a fluid-filled pilot bore is drilled using a fluid-driven motor at the end of a bend-sub, and is then enlarged …

Aug 16, 2006

Modules

Trenchless 101 - Part VIII - Horizontal Directional Drilling

Aug 15, 2006

Modules

Trenchless 101 - Part VIII - Horizontal Directional Drilling

Construction site arrangement

(Image: Add-on systems - Mini drill rig (CASE 300 CM) with 56 kN pulling force mounted to a compact loader [FI-Case])

Usually, horizontal directional drilling requires no starting and target shafts but merely starting and target pits at the entry and exit point of the drilling for catching the flushing fluid and the spoil.

(Image: Mega boring rig at construction site [FI-Herreb]) (Image: Drill rig at construction site [FI-Vermea])

Aug 16, 2006

Modules

Trenchless 101 - Part VIII - Horizontal Directional Drilling

Construction site arrangement

(Image: Construction site arrangement when using a mega drill rig with reference to [DCA95] [Image: S&P GmbH] - Construction site arrangement at the exit point (pipe site))

The dimension of the drill rig, type and outer diameter of the line to be installed, the boring length and the pulling.in method significantly define the requirements concerning the required space, the accessibility and the equipment on the construction site arrangement.

In general …

Sep 12, 2006

Modules

Trenchless 101 - Part VIII - Horizontal Directional Drilling

Aug 16, 2006

Modules

Trenchless 101 - Part VIII - Horizontal Directional Drilling

Process specification

(Image: Working steps for horizontal directional drilling (underground crossing of a river) with reference to [DCA01] [Image: S&P GmbH] - Pilot bore)

The process contains of the following working steps [Kleis96a] [DCA00c] [Stein96d] :

  1. pilot bore
  2. reaming bore
  3. pulling-in procedure.
(Image: Working steps for horizontal directional drilling (underground crossing of a river) with reference to [DCA01] [Image: S&P GmbH] - Reaming bore) (Image: Working …

Aug 16, 2006

Modules

Trenchless 101 - Part VIII - Horizontal Directional Drilling

Process specification

(Image: Working steps for horizontal directional drilling (underground crossing of a river) with reference to [DCA01] [Image: S&P GmbH] - Pilot bore)

For the pilot bore the drill rig is normally positioned on the ground surface. The bore hole is planned with an angle of 5° to 35° at the entry point (starting pit) and is sunk to the planned installation depth. After reaching the nominal depth the drilling is aligned horizontally and is continued …

Mar 07, 2007

Modules

Trenchless 101 - Part VIII - Horizontal Directional Drilling

Process specification

(Image: Rotation and thrust of the drill rod string = straight forward)

Rotation and thrust of the drill rod string = straight forward

(Image: Thrust of the drill rod string without rotation and the steering face points at 12 o'clock = upward movement)

Thrust of the drill rod string without rotation and the steering face points at 12 o'clock = upward movement

(Image: Thrust of the drill rod string without rotation and the steering face points at …

Aug 16, 2006

Modules

Trenchless 101 - Part VIII - Horizontal Directional Drilling

Process specification

(Image: Working steps for horizontal directional drilling (underground crossing of a river) with reference to [DCA01] [Image: S&P GmbH] - Reaming bore)

Reaming bore is characterised by once-only or repeated pulling back of the drill rod string towards the entry point (starting pit). At the same time by means of a rotary-flushing reamer the bore hole is widened up to the diameter which can be 50% wider than the largest outer diameter of the line(…

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