Trenchless Technology Scope of Works Manual

Table of Contents



It is our privilege to present the Trenchless Technology Scope of Works Manual. The manual details the expected scope of work that would have to be executed to successfully conclude the trenchless portion of a construction project employing trenchless technology. Trenchless is applied for subsurface construction works and addresses four major phases of utility life cycle. These phases are subsurface investigations, new utility construction, rehabilitation of existing utilities, and finally replacement of deteriorated buried utility. All these works are executed through application of suitable trenchless techniques or an appropriate combination thereof. This combination is generally made by matching and mixing some common techniques like subsurface investigations, development of entry and exit shafts, pipeline condition assessment, pipeline cleaning etc. with the main trenchless technique like directional drilling or pipe jacking or lining or pipe bursting as per the project requirements. The manual, therefore, is also structured into four main sections, common items, new installation techniques, rehabilitation techniques, and finally replacement techniques for a better usage.

The manual is intended to serve as a reference book for identifying the scope of common trenchless techniques. In addition it is also aimed to become an assistance tool for trenchless project supervision and inspection works, basis of rate analysis for items of trenchless technology, trenchless prequalification process assistance tool, and operator skill evaluation tool. It is aimed at providing inputs to project planning and executing engineers engaged in the subsurface utility development and management activities requiring trenchless applications. It is also expected to be beneficial to consulting engineers rendering advisory services for such works. A word of caution is offered here about the requirement of experience and expertise for trenchless works. The stipulations provided in this manual are meant for professionals with adequate experience and understanding of subsurface construction works. Basic understanding of Trenchless is imperative. These stipulations must not be applied without proper understanding of related issues. Readers with initial knowledge of trenchless techniques should refer to manual stipulations for reference only and get the guidance of experienced trenchless professionals in their applications. For an example, pneumatic pipe ramming technique sends impulses in the ground strata and if it is applied inconsiderately it may lead to damage of other buried utilities, appurtenances, or structures in the vicinity. Or pipe jacking may lead to soil heave if execution fails. Such issues are addressed in detail in IndSTT Standard Operating Procedure Manual apart from other related books and codes and readers are encouraged to refer to such books before embarking upon trenchless projects.

To use this manual for supervision and inspection activities, reader needs to choose the technique set expected to be applicable for executing a specific project. The detailed scope of work for each selected technique, as presented in the manual, then can be aggregated to identify the complete scope of work for that project. This selection then is to be analyzed for omissions or commissions of activities that may be needed for the success of the entire project. There can be few actions that may be a part of more than one chosen techniques and such repeated items need to be removed from the complete work scope. Alternatively, selected technique variant or the project setting may require execution of some additional items of work, not listed in this manual. Those items need to be included in the entire work scope. Further in majority of cases, projects employing trenchless technology also require conventional construction works. The complete work compliment for the project would be the combination of work scope for trenchless works and the conventional works. The manual provides the scope of work for trenchless and related items only. The conventional works are beyond the purview of this manual and reader may refer to appropriate specifications for their details. Works manuals by CPWD can be useful in that context. Once the complete scope of work is developed reader can embark upon the project work as a supervising or inspecting professional.

Readers desirous of using the manual provisions for conducting the technocommercial analysis need to understand that the stipulations provided in this manual are on a generic basis. They need to be adopted appropriately to cover the entire work scope of any specific technique, equipment sizing, and material specifications to evaluate a specific rate. Similar to supervision or inspection works, rate analysis for trenchless works is also a specialized activity and engineers embarking on that must have proper understanding of the project and technique requirements. As has been highlighted earlier, the manual provides the common and expected items of works. Any special input needs to be evaluated and justified prior to being used, user experience, therefore, is of paramount importance.

Finally, before concluding, it would be appropriate to mention that trenchless techniques are evolving and maturing on a very fast pace and the manual will have to be amplified on a regular basis to cover the developments and enhance the coverage. IndSTT invites the readers and technology developers to provide inputs for such revisions as and when developed. In addition, should a reader feel that new techniques be included in the future editions of this manual or the work scope of any particular technique be revised, he or she may provide the necessary inputs to us for necessary actions.

It is expected that the manual will be able to provide necessary inputs in its chartered areas and be able to promote the trenchless application properly. We shall look for comments from the readers for future editions of this manual.

Dr. Niranjan Swarup
Director General
Indian Society for Trenchless Technology

Table of Contents


Sl. No. Chapters
(I) Chairman's Message
(II) Preface
1 Introduction to Trenchless Technolog Scope of Works Manual
  Manual Introduction
2 Common Items
  2.1 Subsurface Survey
  2.2 Dewatering
  2.3 Excavation of Pits
  2.4 Temporary bypassing of Sewer
  2.5 CCTV Pipeline Condition Assessment
  2.6 Manhole Connection
  2.7 Sewer Pipeline Desilting
3 New Installation Techniques
  3.1 Moling
  3.2 Pipe Ramming
  3.3 Horizontal Directional Drilling (for laying HDPE and Steel Pipes)
  3.4 Manual Pipe Jacking
  3.5 Auger Boring
  3.6 Guided Auger Boring
  3.7 Tunnel Boring
  3.8 Microtunneling
  3.9 Rock Boring
4 Rehabilitation Techniques
  4.1 Slip Lining
  4.2 Cured in Place Pipe
  4.3 Sprayed Lining
5 Renewal Techniques
  5.1 Pneumatic Pipe Bursting
  5.2 Static Pipe Bursting
(A) Appendix
A1 Geotechnical Investigations