Engineering

On practically every construction project involving soil, whether excavating, moving, or building atop, there is usually a geotechnical investigation. The report is financed and commissioned by the owner and project design engineer for the purpose of obtaining soil properties relative to the structural stability and longevity of the project.  The basic exploratory program most often … Read more

I recently received a question regarding sloping at the open end of a trench shield that was being used on a pipeline project.  The manufacturer’s tabulated data was unclear on the issue and an inspector was required that the sloping adheres to the OSHA Appendix B for sloping and benching. This is a prime example … Read more

Arch spreaders are used on shields for the specific purpose of raising the clearance from the underside of the shield spreader to the bottom of the excavation. Most often this is used for large-diameter pipe and box culvert installations. Typically, clearances can be raised from 5 ft to 8 ft with the use of an ... Read more

Site-specific shoring plans originated in response to OSHA Subpart P-1926.652(c) (4) Option 4, Design by an Engineer. In the standard, OSHA states: 1926.652(c)(4)(i)- Support systems, shield systems, and other protective systems not utilizing Option 1, Option 2, or Option 3, above, shall be approved by a registered professional engineer. 1926.652(c)(4)(ii)-Designs shall be in written form … Read more

Roles and Responsibilities This article looks at the roles of major players involved in producing a shoring system, as well as their responsibilities. One way to do this is by looking at risk and litigation when something goes wrong. In the United States, all industries are subject to litigation, this article looks at the four … Read more

In almost all cases, a Competent Person must first classify soil in accordance with the OSHA Appendix A Soil Classification prior to selecting open-cut sloping or a manufacturer shoring system for a project. The appendix outlines three soil types in descending order of stability, Type A, Type B, and Type C. Anyone that works with … Read more

It is well understood that the use of shoring equipment requires regular inspection and maintenance. Understanding how to inspect a shoring device, what needs to be focused on, and how to make practical decisions about what is observed, is not so clear.  Steel shoring shields have very long lifetimes, which depend on how the product … Read more

On June 19th through 24th, the National Utility Contractors Association (NUCA) will be sponsoring a Trench Safety  Stand-Down to raise awareness and prevent accidents in excavation work.  One of the major ideas behind a safety stand-down is to increase awareness and focus on safety by encouraging participants to stop, think about safety, and determine ways … Read more

National Trench Safety recently previewed its newly developed telemetric pin at the CONEXPO/CON-AGG construction equipment show in Las Vegas, Nevada. The telemetric pin was installed within the leg of a hydraulic excavation brace supporting an in-ground slide rail pit. As part of the demonstration, hydraulic loads were applied to the pin which was wirelessly transmitted … Read more

There are many requirements within OSHA Subpart P that may not be entirely clear. One requirement that I continually get questions on is what we call the” 2-ft rule”.   The 2-ft rule provides that a protective system, such as shoring shields and hydraulic shores, cannot be held more than 2-ft off the bottom of an … Read more

It starts with what’s perceived as a great idea to accomplish things better, faster, and or safer. It always seems like a no-brainer to adopt great ideas and improve how things are done in hindsight. Inventors and entrepreneurs invest huge sums of time and money into developing and refining these ideas.  Once the inventor or … Read more

Excavation support and shoring decisions can be complicated. The number of soil conditions and variables that go into defining the problem and the shoring system alternatives to choose from can be overwhelming.  The results of getting it wrong can be very expensive while being overly cautious can result in not getting awarded the job or … Read more

Excavation work presents several situations where temporary access bridges can be necessary. One common example is a pipeline excavation utilizing shoring shields combined with sloping, which will require a bridge to provide worker access from the unsloped surface to the shoring shield.  OSHA Subpart P, 1926.651(l) provides some guidance in this respect:  “Walkways shall be provided … Read more

At National Trench Safety we are in the process of developing useful shoring cost estimating information for construction managers and estimators. In the process, I am developing a series of articles about the estimating process. Construction cost estimating can easily be broken down in a systematic way. Everything that goes into building anything can be … Read more

Water has an undeniable impact on the selection of shoring systems. The presence of water can have a significant impact on soils, which is why water is commonly mentioned in most manufacturers ‘ tabulated data.  The water table tells the contractor where to expect water, it’s based on soil sampling on a specific job site, … Read more

A site-specific plan begins by using the actual soil condition from the job site, whether from a soil report from the project or in the absence of a formal soil report, visual observations, and assumptions that are verified at the time of excavation and shoring installation. With a site-specific plan, the interpretation of the soil’s … Read more

One of the more interesting questions I receive from contractors well versed in both the excavation standard and manufacturer’s tabulated data regards the application of OSHA’s 20-ft depth requirement for site-specific engineering. Quite often I hear the statement “Anything over 20 feet deep must be designed by a registered engineer.”  There is a lot of … Read more

I recently served as an expert witness in a wrongful death (involuntary manslaughter) case in California related to a trench collapse.  In this particular case, the court held the prime contractor and project manager personally responsible for not following state laws regarding worker protection in excavations and sentenced each to two years in prison.  This … Read more

This article is the second of a three part series regarding manufacturer’s tabulated data. When reviewing the obligations of tabulated data there are certain requirements of the user of the tabulated data. Those requirements include the following: Employer’s Competent Person must determine the load that will be placed upon the shoring system, which include the … Read more

This article will be the first of a three part series regarding manufacturer’s tabulated data. According to the OSHA Subpart P Excavations standard, “tabulated data” means tables and charts approved by a registered professional engineer and used to design and construct a protective system. The purpose of this tabulated data for shoring equipment is then … Read more

It is not known who coined the term “induced hazards”, but OSHA uses the term and defines it as hazards that “arise and are induced from a multitude of incorrect decisions and actions that occur during the construction process.”  Part of the reason for the development of these hazards, is the production mentality of many … Read more

Federal and State interstate commerce regulations along with the Federal OSHA regulations state that for manufactured shoring and shielding equipment, the structural certification stamp from the state where the shoring is manufactured is to be accepted in all states. The following definition applies to this: 1926.650(b)-Definitions applicable to this subpart. “Registered Professional Engineer” means a … Read more

  First, I am not an attorney and I am not giving or providing legal advice here, but I will try to address some questions many of us deal with in our industry today. A routine question that I receive when instructing or attending a Competent Person for Excavation Safety training seminar is if the … Read more

One of the most complicated and least understood requirements of the OSHA Subpart P-Excavations Standard is surcharge loading. There is very little information provided about how to determine and deal with surcharge loads, while there is a lot about requiring the competent person to consider surcharge loads in shoring selection decisions.  Here is the requirement … Read more

The Occupational Safety and Health Administration (OSHA) establishes basic standards for employee protection when working in and around excavations.  These standards are very important for keeping employees safe, as well as establishing employer responsibilities.  The OSHA standard addresses excavations in 1926.652(a)(1) specifically stating that employees must be protected from cave-ins while working in excavations.  A … Read more