Recommendation – Education – Networking
Since January 2018, the DCA has been offering a new event, the so-called DCA Members‘ Forum HDD Technology. The forum offers a platform for members of the association to exchange experiences and is primarily aimed at site managers and maschine operators, but is also open to interested technical supervisors, planners and clients as well as interested parties from the supplier industry.
Participation in the forum is free of charge and reserved exclusively for members. From 2021, it is planned to hold the event parallel in two linguistically separate rooms (German-speaking/English-speaking groups).
The Members‘ Forum HDD-Technology will take place for the third time in 2021 in Aachen. After the kick-off event at the beginning of 2018 at DCA member Open Grid-Europe in Essen on the subject of “HDD-Trouble Shooting”, this time the association will focus on the subject of “subsoil investigation”. This year the HDD workshop will take place for the first time in two linguistically separate groups.
Note: Due to the current Corona situation, the Board has decided to postpone the event to a later date in 2021. The new date will be announced soon.
The use of HDD-technology requiresprecise information on the subsoil based on accurate soil investigations in order to be able to reliably assess the feasibility of a project and to reduce the subsoil risk to a minimum. In order to obtain this information, dedicated soil investigations by an expert are necessary.
The planning of the necessary investigations, the professional supervision of the field and laboratory work and the preparation of a geotechnical investigation report (subsoil expertise) must be carried out by a qualified subsoil expert with relevant knowledge and experience of the working methods and special features of HDD technology. The report should specifically address the specific, constructional aspects in connection with the application of the HDD technique in order to enable an assessment of the drillability of the encountered soil layers
Aim of the workshop
The aim of the HDD workshop “Soil Investigations” is to firstly examine and evaluate the HDD-specific geotechnical parameters and terminology used in a soil expertise. In addition, it will be discussed which minimum requirements have to be met and which parameters are advantageous for which conditions, i.e. what significance the individual parameters have.
The workshop is primarily aimed at decision-makers, project and site managers, technical supervisors as well as planners and clients of DCA member companies, but is also open to foremen and HDD rig operators trained according to GW 329 (Germany). Participation in the event is free of charge and exclusively reserved for DCA member companies.
Topics of the workshop:
“Soil investigation” – Which parameters are important for HDD, what are the requirements for HDD drilling?
- What are the exploration methods, how are they applied, what methods are available for sampling in situ?
- What laboratory tests/analyses are carried out?
- What information can be derived from the parameters determined?
- What influence do the data have on the planning of the drilling?
- What are the minimum requirements for soil investigations?
- What is the overall interpretation of the subsoil expertise?
- Dealing with “special features” in the subsoil (Atterberg state limits, swellable clays, abrasiveness in solid rock, etc.)
Dr. Tim Jaguttis, Vice-President DCA,
Dr. Christoph Donié, Dr. Donié Geo-Consult GmbH
Dan Lingenauber,Tracto-Technik GmbH & Co. KG
Program – Registration
Welcome, introduction and moderation: Dr. Tim Jaguttis, Vice-President DCA
|09.15 – 10.00 am||Workshop – Session 1|
|10.00 – 10.30 am||Break|
|10.30 – 11.30 am||Workshop – Session 2|
|11.30 – 12.30 pm||Workshop – Session 3|
|12.30 – 13.30 pm||Lunch break|
|13.30 – 14.30 pm||Workshop – Session 4|
|14.30 – 15.30 pm||Workshop – Session 5|
|15.30 – 16.00 pm||Final discussion|
Participation is free of charge and reserved for DCA member companies.
Registration: Dipl.-Geol. Antje Quante; firstname.lastname@example.org
The 3rd DCA Member Forum, which took place in Aachen under the theme “New trenchless techniques linked to HDD technology” at the end of January 2020, was well attended with 23 participants. 10 regular and 13 associate member companies, including clients from both gas pipeline construction and cable laying, took part.
At the last annual congress in Krakow in October 2019, the Drilling Contractors Association (DCA) held a workshop on “New trenchless techniques linked to HDD-technology “, in which the areas of application of the methods as well as the advantages and disadvantages compared to the HDD technology were discussed intensively with the participants. In addition to the above mentioned points, the application limits and the costs of the individual methods were also discussed. The methods compete with HDD in the field of large and small drilling technology and complement the classical construction method. In the course of the intensive discussions, the necessary specialist knowledge for the users was discussed and answers were found to the question of which processes can usefully supplement the HDD companies’ offerings. However, it quickly became clear that there was still a need for further clarification and information among the members due to the limited time frame in the very well attended workshop.
During the event in Aachen, a total of five methods were presented and intensively discussed by parts of the board and by Jörg Himmerich of DCA member Dr.-Ing. Veenker Ingenieurgesellschaft mbH from Hannover. The methods discussed included the Direct Pipe, the E-Power Pipe, the Easy2jet, the pilot pipe jacking method and last but not least the Direct Drill method.
Points for discussion:
- What/where are the limits of each technique?
- What are the advantages and disadvantages (compared to HDD)?
- What kind of knowledge is required (HDD or Microtunneling or …)?
- Which technique(s) could be reasonable expansion for HDD companies?
- Can HDD in future improve where other methods have advantages?
These and other questions were discussed between clients, manufacturers and users during the very informative members’ forum.
The characteristics of the individual methods are listed in a table below.
On 05.02.2019 the second DCA member forum HDD-Technology took place this time in Aachen. The event was held as part of a workshop on the topic “Requirements for small drilling technology”. A total of 18 people took part in the members’ forum. Nine drilling companies, three planners and one client and further suppliers were present. Three participants had to cancel due to illness.
The following points were discussed:
Definition Small Scale Drilling
- an exact definition of small drilling technology – what is small drilling technology, where are the limits to large drilling technology? – is not possible
- the splitting of the HDD technology according to the tractive force of the drilling rigs (>, < 40 t) is used in HDD training/certification (GW 301/329), but is by no means valid for all HDD measures
- the complexity of the drilling is an important factor, even small drillings with short drilling lengths can be very demanding
- In Germany, so-called small drilling technology accounts for around 95% of all drilling work (drilling rigs KB: approx. 1200; GB: approx. 15).
Requirements in the DCA-Guidelines to small scale drilling technology
- By far the largest part of the requirements in the DCA guidelines applies to both large and small drilling technology.
- The statement of many HDD companies that the requirements in the guideline only apply to large drilling technology is simply wrong.
- The subject of materials in the TR: It is suggested that permissible pipe loads and qualities for PE should be supplemented.
Project classification according to degree of difficulty (see chapter 10.5.1 ff of the TR)
- In the DCA Guideline, an attempt was made to classify projects according to their degree of difficulty (originally from the 2004 QM Guideline).
- Categorization of drillings into routine, standard and complex drillings
- As a result of the discussion in the workshop it can be stated that the topic “categorisation” incl. Tables 11 ff must be completely revised.
- It is also proposed that a separate document be drawn up for categorisation. This document could serve as an aid for clients and planners in the tendering and planning of HDD measures.
- The revised categorisation is also intended to sensitise clients/planners/contractors to the requirements of HDD construction measures.
Drilling mud disposal
- Presentation of the results of the task group.
- There is no generally valid recommendation for drilling mud disposal from DCA.
- One approach proposed is the so-called Danish model for a fair solution between clients and contractors; clients must take action and conclude “contracts” with disposal companies/landfill operators; then regulate disposal in the bill of quantities via separate positions; DCA-bill of quantities should be reviewed to that effect.
- Drilling companies report on their own experiences: e.g. disposal of the drilling mud via a specialist disposal company (Maschinenring in Northern Germany) or establishment of their own specialist disposal company via which the disposal is then carried out (e.g. Beermann).
Dealing with inadequate planning on the construction site/ Dealing with unreasonable demands of the client etc.
- Various example projects on this topic will be presented and discussed. In the course of the discussion, there will be a lively exchange of experiences between all participants, which will not be further deepened here.
- The basic recommendation is given that deviations from the course of the project or additional services should be reported in writing to the client / planner in a timely manner. This also applies to planning errors in the course of the invitation to tender or during the execution of construction work.
- It is suggested that contracting authorities/planners be trained by DCA in order to raise the level of tendering and the quality of monitoring of the measures.
Conclusion: The continuation of the event in this format is expressly advocated. The topics addressed should be further explored in further events. The overall too small number of participants was criticized, especially on the part of the client.
Since January this year the DCA offers a new event, the members‘ forum, which took place for the first time on 18th of January, 2018 in Essen. The forum offers a platform for members of the association to exchange experiences and is aimed at construction companies and executives, but is also open to interested professional supervisors, planners and contractors as well as interested parties from the supply industry. Under the motto “HDD Trouble Shooting”, the DCA has set itself the goal of building up a kind of “fault culture” within its members. Errors are not necessarily to be seen as a flaw in the performance of the service, but are much more to be understood as a deviation from the original plan. As a result, a role is also played in the case of mistakes/errors (e.g. of the geology).
The HDD drilling companies in the DCA is fairly well known the unplanned and undesired events that can cause additional work or expense in practice during the drilling operation. Lack of drilling fluids, blowers, drill pipe breakages, tool wear,… are only a few points from the multitude of problems to be solved. If possible, these experiences will be kept in the companies under lock and key. Or the experiences they have gained will be seen as a future competitive advantage and thus well guarded.
In order to increase the quality and reliability of the HDD process as a whole, these experiences should be used more and more in the volume. Finally, all active DCA members are also competing with each other, both with conventional pipe laying and with other construction projects.
According to the participants, the first event was characterised by a lively discussion, which resulted in an exchange of experiences, both in the field of large drilling technology and for operators of small and medium-sized systems. All participants, whether drilling companies, planners, clients or suppliers, took an active part in the discussion, so that the executive board strives to further expand this format of mutual exchange, also of its own “mistakes”, for its members in the future.
In the context of the first member forum, the following content-related points were discussed/developed (excerpt):
Drilling fluids/topic blowers:
- The term “blower” has a negative connotation and should rather be avoided by experts. It is suggested that an information sheet on the subject of mud eruption be compiled (causes, technical course, boundary conditions, countermeasures, etc.). The information sheet should be distributed to the clients, agencies and planners.
- the necessity of soil exploration is basically given for every HDD project (recourse to existing data, reconnaissance). In practice, unfortunately, the client often dispenses with the necessary examinations. The result: a supposedly cheaply purchased construction work becomes more expensive in the end than if it were properly planned right from the start.
- If the ground in the project is different than planned, prompt coordination with the client is recommended (keyword: notice of obstruction).
- The quality of the subsoil report must still be improved (keyword: further training for planners and clients)
Cooperation clients/planner/drilling company/supplier:
- The training of clients and planners for the HDD procedure is suggested (last training took place in 2012, keyword HDD quality assurance from the client’s point of view)
- The topic of railway crossing using HDD should be discussed in the HDD discussion forum.
- This topic is currently being discussed in working group 2 “coating”.
- The responsibilities regarding coating must be clearly defined in a project; in practice there are different models.
- The quality of the coating must be adapted to the requirements resulting from the subsoil. This is often not the case.
- Damage often occurs on the post-coating; quality requirements must be observed.
- Quality and maintenance of the tools used is always the responsibility of the contractor; there are various procedures for testing:
- Within the scope of quality assurance, every company must have a system for self-monitoring of equipment (maintenance, wear, material fatigue, etc.)