We had the pleasure of providing structural engineering services on this modern style commercial office building in College Station, Texas for JaCody Construction.
Besides showcasing a sleek exterior that is complementary to the surrounding community, the building will house office space for the fast growing real estate firm, TM5 Properties which is owned and operated by former Texas A&M and NFL wide receiver Terrence Murphy.
TM5 Properties is a real estate brokerage that consists of only full-time Realtors and experts of the local real estate market. We pride ourselves on hard work, knowledge and integrity to achieve superior results for our clients. Our strategy is a coherent set of actions aimed at gaining a sustainable advantage and to achieve complete dominance in the BCS real estate market.
Located in the heart of ‘Aggieland’, also known as Bryan/College Station, we are willing to put our modern, cutting-edge practices and services up against any competitor in the Brazos Valley. Our mission and focus is to be the #1 real estate brokerage in the local market and top of mind of all customers when they consider buying, selling or renting.
We commit to stay atop of the most current trends, contemporary practices and all aspects in the real estate industry. This is our mission and how we create unique value to our clients and are distinctive from other real estate brokerages in our real estate market.
Going vertical at our 3-story, 100,000+ SF self-storage project (SAFStor – Old Spanish Trail) in Houston, Tx. The CMU walls will form the elevator and stairs shafts as well as serve as the lateral load resisting element for the building. #structures#selfstorage#houston
In the world of climate-controlled, multi-story, self storage, SAFStor is leading the way with new developments underway across the country. With ambitious expansion goals and tight construction schedules, SAFStor selected ARCO Design/Build to lead the development process as the design/build contractor. Based on our experience with both self storage and cold-formed steel design, Dudley Engineering was selected based on qualifications to provide the structural engineering for these developments.
Multi-Level Self Storage
Multi-level self storage is a relatively new development in the world of self storage that is gaining steam particularly in densely populated areas. From a structural perspective, multi-level self storage facilities require a much more in-depth analysis of load paths and material behavior when compared to conventional single-story self storage facilities.
Modern single-story self storage facilities typically fall within the wheelhouse of metal building companies and are constructed out of cold-formed zee and cee members with metal panel for the walls and roof. Our scope on these projects is typically limited to providing the foundation design and reviewing the metal building submittal to confirm whether it is in general conformance with the building code.
Conversely, multi-story self storages facilities generally necessitate full-service structural engineering firms such as Dudley Engineering to design both the foundation and superstructure.
Reasons to involve a full-service structural firm include:
Complicated load paths stemming from:
Office/Public space on the 1st Level which require transferring the load bearing walls above.
Unit configurations varying from level to level.
Multiple materials utilized in the construction that are required to behave amicably. For example, a large portion of lateral resistance of the structure is typically derived from the stair and elevator shaft walls which are usually constructed out of concrete masonry units (CMU). Conversely, the primary gravity load resisting components are cold-formed steel stud walls.
Integration of ancillary components such as canopies, awning and parapets that are typically outside the expertise of metal building companies.
Below is an image of the SAFStor project in South Houston along with some example of the framing used.
To learn more about this project, the design-build process or the framing system contract Bryan Tyson, PE (Project Manager and Engineer-of-Record) at firstname.lastname@example.org or Drew Dudley, PE (Principal-in-Charge) at email@example.com.
Form follows function is a principle associated with 20th-century modernist architecture and industrial design which says that the shape of a building or object should primarily relate to its intended function or purpose. This principle is beautifully showcased in the recent design and construction of Drew’s Car Wash at Tower Point. The buildings longitudinal plan and modern architecture portray its intended function as a modern touch-free car wash that is inviting and intuitive to the customer.
Drew’s Car Wash Location
The newest addition to the Drew’s Car Wash chain is located at 4442 SH6 South College Station, Texas (near the HEB at Tower Point).
Car Wash – Structural Design
The structural frame for the car wash consists of structural steel hollow structural sections (HSS) that are bolted together via hidden internal connections. The lateral frame consist of a steel moment frame in which lateral drift is controlled by specifying the high-strength bolts to be pretensioned. Dudley Engineering provided the special inspections of the pretensioned bolts which were achieved via the turn-of-nut method.
Dudley Engineering also provided the structural design and renderings for the vacuum and ticket canopies. The design of the vacuum canopies is intended to provide shade for customer as they access the complimentary vacuums and towels. The front eave of the canopy drops down to conceal the vacuum hoses.
Car Wash Canopies – Wind Design
Design of the open-structure canopies presents challenges when designing for wind. Since the canopies are open, as opposed to an enclosed building in which wind is not able to pass through the structure, wind pressure is able to build up on both sides of the canopy roof. Positive pressure (toward the surface) is induced on the bottom of the roof while negative pressure (away from the surface) builds-up on top of the roof. The total combined pressure is substantial and must be resisted by the HSS beams and columns which are all rigidly connected to provide a complete and stable structural frame.
West 34 1/2 Street, Houston, Texas near Oak Forest
This development consists of (25) individual townhomes each consisting of a three-story unit of approximately 3,000 square feet. There are (4) unique models with each model having floor plan and elevation options to allow customization. For a full description of the option visit the architect (Moment Architects) page, link below.
The structural consists of a post-tensioned stiffened slab-on-ground foundation with conventional 2×6 (exterior) and 2×4 (interior) wall framing, wood floor trusses and then a mix of wood roof trusses and conventional braced rafter roof construction.
Structural OSB sheathing was used for the shear walls with Simpson Strong-Tie holdowns.
To resist the high wind speeds prevalent in Houston, we utilized Simpson Strong-Tie hurricane clips and straps to form a complete load path.
Every commercial project brings forth its own set of unique challenges. Dudley Engineering has found success in meeting these challenges by consistently applying our core values and following a tried and true framework that guides us through the entire project life cycle.
Dudley Engineeringis well versed in the intricacies of small to large commercial projects. Below we discuss the phases of a typical commercial project life cycle from the perspective of a structural engineer. An illustration of this life cycle is included at the bottom.
In schematic design (SDs), Dudley Engineering will
Collaborate with the architect and owner/developer to determine which structural frame is the best option for the project. Due to Dudley Engineering’s experience with all major structural framing systems and materials (structural steel, reinforced concrete, post-tensioned concrete, timber, cold-formed steel, conventional wood framing, engineered wood, metal building systems & CMU) we are able to view the project from a wider perspective. To contrast, larger structural engineering firms primarily only work with structural steel and reinforced concrete and thus will view all new projects from that paradigm, “the man who is good with a hammer tends to think everything is a nail” – Abraham Maslow.
In addition to structural design for new construction, Dudley Engineering also offers structural condition assessments for adaptive re-use and renovation project. Our structural condition assessments can identify issues with the primary structural frame as well as with the building envelope. For more information about specific projects in which structural condition assessment were performed view the following links. Assessing Fire Damage, First Baptist Church Huntsville – Renovation
At the start of Design Development (DD’s), a 3D finite-element structural analysis model will be created if it was not already created during SD’s. This model incorporates the primary structural framing members, design loads, environmental loads (wind and seismic) and support conditions. After analysis is complete, we will begin designing the individual components (columns, beams, shear walls, braces, etc.) of the structural frame utilizing the forces and reactions from the analysis model.
We will repeat the analysis – design loop iteratively until we reach an optimum solution that provides a clear and logical load path that is also economical. It is a common fallacy among inexperienced structural engineers to believe that the most economical solution will always be the least weight option. This fallacy is exacerbated due to the typical trend in the industry for structural engineering firms to defer segments of the structural design such as structural steel connections and cold-form steel framing. For example, if an engineer is not conscious of the structural steel connection design then they may be tempted to size a short-span girder with a smaller section than the long-span beam that it supports. When viewed in a vacuum, absent concerns for the connection design, this may seem like the most economical option since it is reducing the tonnage of the steel frame. However, to make the connection work, the long-span beam will need to be coped and stiffened in order to connect into the shallower girder. When viewed holistically, it is more economical to specify a deeper girder which will reduce fabrication time.
During DD’s, Dudley Engineering will also share typical and project-specific details with the general contractor (if on-board at this time) for feedback on constructability and cost/schedule impacts.
Construction documents (CD’s) can take of many forms including 50%CD’s, 75%CD’s, 95% CD’s, etc. until eventually 100% CD’s are completed and are indicated “For Construction”. It is in this stage of the project that we make the finishing touches on details, connection material, miscellaneous steel, etc. all in an effort to provide the contractor will a complete set of construction documents that inform the contractor how to construct the structural components of the building in order to meet the needs of the owner as well as to protect public health, safety and general welfare.
During the construction administration (CA) phase, the design team reviews submittals, responds to RFI’s from the contractor, responds to comments from the Authority Having Jurisdiction (AHJ) and conducts observations and/or inspections of the construction progress.
Submittals are submitted by the contractor to the design team for the purpose of verifying that the contractor has correctly interpreted the construction documents. Submittals include: Shop drawings (e.g. structural steel erection and fabrication, reinforcement layout and cut sheets), Concrete Mix Design, Product Data (e.g. CMU Block Material). The design team reviews the submittals for general conformance with the construction documents and returns them indicated as either No Exceptions, Exceptions Notes, or Revise and Resubmit.
C-Store Design: A Blend of Structural Steel and CMU Construction
The type of foundation utilized for C-Stores is dependent upon the results of the site-specific geotechnical report, however due to the light loading from the superstructure the foundation will not necessitate deep foundations (drilled piers, auger cast piles, etc.). For foundations on non-expansive soil, continuous spread footings with a non-structural slab are commong. For foundations on expansive soils, stiffened slab-on-ground foundations are typically utilized since the controlling loading will be the active soil and not the superstructure loading.
Typical C-Stores are constructed with CMU (concrete masonry unit) walls and structural steel open-web roof joists. The CMU walls serve as the load bearing element for both gravity loading (dead, live, snow, wind uplift, etc.) and as shear walls for lateral loading (wind, seismic). Open-web steel roof joists are a practical option for the roof framing due to their truss configuration which allows them to span large distances at a relatively low cost. The front of the C-Store is typically framed with structural steel columns and beams due to the large storefront windows that preclude the use of CMU walls.
Fuel tanks present a special condition for C-Store design as they can become buoyant during flooding events. For example, the self-weight of a 20,000 gallon fuel tank is approximately 10,000 pounds. Assuming that the soil has become saturated and the fuel tank is empty, the buoyant force will be approximately 165,000 pounds. To overcome this buoyant force, deadmen anchors are employed to provide additional restraint.
The fuel canopy structure typically consists of HSS (Hollow-Structural Section) steel columns with “carry” wide-flange steel beams directly above spanning the short dimension of the canopy which then support the “purlin” wide-flange steel beam spanning the short direction. The metal roof deck is fastened to the soffit (bottom) of the steel beams. The HSS columns are typically founded on deep foundation elements.
This function of this building will be a service center for automobiles and RV’s including but not limited to oil changes, state inspections and mechanical service. The building is two-stories with the bottom story being a basement (highlighted in yellow below).
Basement (Pit) – Cast-in-place concrete walls with isolated spread footings for the interior columns.
Structural Floor Above Pit : Composite concrete deck with 1½ composite metal deck with 4½” of reinforced concrete for a total thickness of 6″. The composite deck is supported by composite structural steel beams which frame into structural steel columns and the cast-in-place concrete basement walls.
Level 1 Slab: Stiffened slab-on-grade.
Superstructure: Metal Building System.
Unique Design Criteria:
The elevated floor of the pit needed to be designed to support a Class A RV which based on our research indicated a 26,000 pound total weight. We utilized the AASHTO HS-10 (bridge design) weight distribution formula which assigns 80% of the weight to the rear axle and 20% to the front axle/ This resulted in a design vehicular wheel load of 10,400 pounds on a minimum contact area of 150 square inches.
Composite construction refers to two load-carrying structural members that are integrally connected and deflect as a single unit. For composite beams, the two load carrying members are the structural steel beam and the concrete on composite metal deck with the shear studs being the element that connects them.
Utilizing composite action creates a stiffer, lighter and less expensive structure than if the two elements were not integrally connected and makes this system one of the choice options for commercial construction.
Typically accompanying composite steel beams is composite deck. Composite deck utilizes the steel deck and the concrete slab to form an integral unit that plays upon the concretes compressive strength and the steel decks high tensile strength. The element that integrally connects these two components are the steel embossment in the metal deck.
Advantages of Composite Construction
Reduced structural steel frame cost compared to non-composite steel construction.
Reduction in time and labor cost due to composite deck serving as both the form deck (which in most cases does not require shoring) and the positive reinforcement in the final structure.
Compared to cast-in-place construction which requires shoring and re-shoring, composite construction can drastically reduce the construction schedule.
Reduction in weight of structural steel frame which also can lead to a less costly foundation.
Reduced live load deflection and improved vibration performance due the composite construction being stiffer than comparable systems.
Potential for shallower beams which can reduce building height.
Increased span lengths are possible.
Disadvantage of Composite Construction
Material cost typically higher compared to cast-in-place concrete systems.
Installation of shear connectors requires specialized equipment (automatic stud welders) which typically mean having to bring on a speciality sub-contractor.
Introduction of camber can create issues with concrete levelness and finishing.
Dudley Engineering was engaged to perform a structural assessment of a foundation in Bryan, Texas that has been exposed to an intense fire. The 4-Alarm fire resulted in a complete loss of the superstructure and wisely the owner engaged Dudley Engineering to ascertain whether the foundation was damaged, prior to rebuilding.
Principal, Bryan Tyson, PE led the assessment which consisted of a visual assessment of the foundation including:
Smoke stains and scorch marks are typically good indicators of areas that were exposed to high heat and require further evaluation (see sounding hammer below)
Concrete exposed to high heat and then subsequently doused with water as is typical in a normal structural fire, can lead to drastic temperature changes and hence quick expansion and contraction of concrete leading to cracks. Consider placing a glass in the freezer and then subsequently removing it and running hot water over it, it will crack (not that we have ever done that before).
changes in color
A change in the color of the concrete may indicate that the concrete was exposed to heat exceeding 550°F. Concrete exposed to temperatures above 550°F often turn a shade of pink which indicates that a chemical change has occurred in the iron-containing aggregates and cement paste.
High heat can cause the pore water in the concrete to evaporate which can lead to spalling of the concrete.
The assessment also included testing of the concrete via a sounding hammer. A sounding hammer can be used to compare the resonance of the concrete after it is struck by the hammer. Healthy concrete will exhibit a sharp, high-frequency ringing sound when struck, while damaged or poor-quality concrete will typically exhibit a dull thud or soft noise.We, in corroboration with may documented cases, have found the sounding hammer technique to be a reliable and cost-effective means of assessing damage to concrete in the wake of a fire. The sounding hammer can also be used for destructive testing to assess the strength of the concrete. Healthy concrete will be unphased by a couple blows from a sounding hammer while heat-damaged concrete will crumble away with a few rigorous hits. Additionally the fracture mechanics of heat-damaged concrete is unique in that the fracture plane will typically form around the aggregate as opposed to directly through the aggregate, which is characteristic of healthy concrete.
Metal Plate Connected Wood Trusses – From Design to Fabrication
We were recently invited to go on a tour of Trussworks, LLC plant in Caldwell, Texas. Seeing the fabrication process and speaking with the truss design manager, Timothy McPeck and general manager, Justin Groom was a great learning experience. Blending the metal-plate connected wood trusses into the structural frame can provide an economical and safe solution for any project of Type III or V construction, however it requires the structural engineer-of-record and architect to have a solid understanding of the capabilities and limitations, this tour certainly put Dudley Engineering LLC a step ahead.
We have completed multiple projects with Trussworks and have found them to be a great partner is helping deliver successful projects.
Wood trusses are common in Multi-Family and light Commerical projects. They have the capability to span large distances while still leaving room for MEP which avoids the need for a drop ceiling.
A Blend of Fine Dining and Innovative Design and Construction
Dudley Engineering blended the cold-formed steel design with the structural steel frame to provide a robust and economical structural system. The structural system consisted of cold-formed steel diagonal strap braced X-bracing lateral system, cold-form steel and structural steel roof joists, cold-form steel roof trusses, and composite structural steel beams with composite metal deck.
The use of cold-formed steel cut down the construction schedule as well as material and labor costs since all the members can be handled by a single laborer and connections can be completed via metal screws in lieu of welding or bolting.
Project Manager: Drew Dudley, PE
Example of Structural Drawings
Contact Drew Dudley, PE at firstname.lastname@example.org for more information or to view a full set of the structural plans.
Dudley Engineering provided structural engineering and building envelope design, consulting and inspection for this church facility which consisted of structural steel framing, cast-in-place concrete basement walls, cold-formed metal framing stud walls and brick veneer. We enjoyed getting to spend time in Huntsville and especially enjoyed getting to eat at the nearby Farmhouse Cafe (@farmhousecafehuntsvilletx) which never disappoints.
Dudley Engineering provided the structural engineering design for the foundation and superstructure of this multi-family development in Spring, Texas.
In collaboration with Moment Architects, Dudley Engineering sought to reduce the structure cost by utilizing advanced framing techniques and engineered wood products.As part of our full-service approach, Dudley Engineering also provided construction administration and inspection services to verify construction.
Drew Dudley, PE Honored as Rising Star in Structural Engineering by Civil + Structural Magazine
Drew Dudley, PE was honored as 1 of 13 recipients to receive the Rising Star in Structural Engineering award from Civl + Structural Magazine which recognizes professional 40 years old or younger working in the United States, who have shown exceptional technical capability, leadership ability, effective teaching or research, or public service benefiting the civil and structural engineering professions, their employers, project owners, and society.
Dudley Engineering’s owner, Drew Dudley,PE was recently published in Insite Magazine! The article explore the causes of expansive soil and dives into the current state of residential foundation design.
Whether you are a contractor, architect, engineer or simply a home owner with a concrete foundation you have most likely heard the adage that “all concrete cracks”. While this is true, there are measures that can be taken to greatly reduce the magnitude and frequency of cracks. To do this, one must have an understanding of the factors that lead to cracking. One such factor is stress concentrations in the concrete which are evident at re-entrant corners. Re-entrant corners are defined as any inside corner that forms an angle of 180° or less. In a solid object that is subjected to internal or external loads, re-entrant corners create high stress concentrations. If that solid object is concrete, which is strong in compression but weak in tension, then it will inevitably lead to a crack that will propagate at approximately 135° from the corner. Re-entrant corner cracks are especially prevalent in concrete slabs that are relatively thin in comparison to their plan size. In this article, I will focus on re-entrant corners in slabs-on-grade.
Examples of loads that can induce stress in concrete slabs include:
Shrinkage of the slab during the curing process when the concrete will shrink in volume as the chemical reaction between the cement and water takes place. Depending on the curing methods in place, the top and bottom surface of the slab will cure at different rates which induces stress in the slab.
Temperature changes. As with all materials, when concrete increases in temperature it will expand and when it decreases in temperature it will shrink. This expansion/shrinkage induces stress in the slab due to restraints such as friction with the bottom of the slab, stiffening ribs, piers etc.
External loads such as additional material or assemblies placed on top of the slab.
There are a number of measures that can be utilized to control re-entrant corner cracks including:
Contraction (Control) Joints: Place contraction joints at the re-entrant corner to create weak planes in the slab that will increase the possibility of cracks forming in the bottom of these contraction joints rather than at ~135° from the corner. Contraction joints can be formed by tooling the joints while the concrete is still plastic or with a saw after the concrete has set. It is important that contraction joints are placed as soon as possible before re-entrant corner cracks begin to form.
Construction Joints: Placing a construction joint 90° to the interior corner eliminates the re-entrant corner and thus the stress concentration.
Wet Curing. Wet curing of the slab will slow down the curing process and will create a more uniform cure rate between the top and bottom of the slab. This has the effect of reducing but not eliminating internal stresses. Wet curing can be accomplished by ponding the slab, utilizing foggers to maintain a humid environment on the slab, or by applying a chemical curing compound. In my experience, ponding of the slab is the most effective means of wet curing however it is typically the least practical.
Water to Cement Ratio: The primary ingredients in concrete are cement, water, fine aggregate and course aggregate. The water chemically reacts with the cement to bind the aggregate in a solid matrix. To fully hydrate cement, a water to cement ratio (w/c ) of 0.26 is required. Additional (free) water is added to the mix to increase the workability of the concrete. As more free water is added to the mix, it increases the shrinkage of the concrete because the free water will eventually evaporate out of the concrete. For our slab-on-grade design, Dudley Engineering typically specifies a maximum w/c ratio of 0.45. Additional workability can be achieved by adding water-reducing admixtures or superplasticizers to the mix.
Fly Ash: Fly ash is a recycled material that can be utilized in limited quantities to replace cement. Replacing a small portion of the cement with fly ash can have the benefit of reducing the expansion of the concrete during curing.
Concrete Additives: There are chemical admixtures which can be added to the concrete mix that reduce the shrinkage rate of the concrete. Recently, on a post-tensioned slab-on-grade foundation that was intended to remain exposed, Dudley Engineering specified a shrinkage-reducing admixture in the concrete. This, along with other measures listed above, has produced a slab that is showing no signs of visible cracks.
To have a slab-on-grade foundation that is relatively crack free even at re-entrant corners, a combination of the solutions addressed above should be utilized. In addition to having a more aesthetic slab, it will also exhibit better structural performance throughout the life of the structure.
In the pursuit of the infamous structural engineer T.Y. Lin’s powerful statement “To engineers who , rather than blindly following the codes of practice, seek to apply the laws of nature” I have always been interested in the subject of advanced framing techniques. The basic premise of advanced framing techniques is “a system of construction framing techniques designed to optimize building materials to produce wood-framed buildings with lower material and labor costs than conventional framed structures. Builders who utilize advanced framing techniques optimize framing material usage, reduce wood waste and, with effective insulation detailing, boost the building’s efficiency to meet today’s energy code requirements. When properly designed and constructed, advanced framed walls that are fully sheathed with wood structural panels, such as plywood or oriented strand board (OSB), provide the structural strength necessary to safely withstand the forces of nature.” (APA The Engineered Wood Association).
For professionals who have experience in structural steel and reinforced concrete framing systems, the definition of “advanced framing” will sound very similar to what has been the standard practice in steel and concrete for decades. The reason this practice is titled “advanced” in the wood industry is due to the wide use of prescriptive design, which has never been prevalent in the steel and concrete industries. It is my belief that the development of the prescriptive design in the International Residential Code has caused the wood framing industry to largely lag behind its counterparts in terms of material and labor efficiency. With the availability of software programs that can readily analyze wood framed structures I think it is time for the wood industry to re-evaluate the widespread use of prescriptive designs and utilize advanced framing techniques to elevate wood framing up to par with concrete and steel framing techniques.
I recently had the opportunity to put advanced framing techniques to the test with my own personal residence. My wife and I designed our 2,800 SF ranch house on our 10 acre property in Montgomery, Texas. For the framing, I designed all of the exterior walls to be 2×6 studs @ 24” O.C. The material savings came out to approximately 30% compared to traditional 2×4 stud walls @ 16” O.C. Other advanced framing techniques that were utilized included:
floor joists and rafters spaced @ 24” O.C. which took advantage of the the subfloor and roof deck’s inherent ability to span distance greater than 16” and reduced the total number of pieces.
Insulated exterior headers which reduced thermal bridging with little detriment to the structural capacity.
Blocking and straps at shear walls utilizing the “Force Transfer Around Openings” analysis approach that reduced the total length of shear walls required.
In the end, the framer was able to successfully implement the design as intended. Besides the material savings, the advanced framing techniques also provide additional benefits such as a larger cavity space for insulation in the exterior walls and less thermal bridging due to the reduced number of pieces in the exterior wall. I consider this implementation of advanced framing a success and look forward to its use on future projects.