Consider designing a four walled concrete pit with a concrete bottom and open top. The walls are 9 ft wide inside. The top of concrete at pit floor is 8 ft below grade with another 2 ft projecting above grade. Would the pit walls be like a retaining wall... [6 replies]
i am looking for suggestions on how to rehabilitate a runway. the project has an existing runway which is in disrepair. meaning there are many potholes and drainage channels throughout due to the high level of rain. the current pavement is onsite crushed... [4 replies]
I have a project in an alleyway between two existing buildings. The alleyway is about 7 feet wide and both buildings have basements that go down about 20 feet. At both ends of the alleyway, a retaining wall must be constructed. The walls will be about 20... [13 replies]
I am currently in the process of designing a number of steel cased bottom driven piles, for Axial Loads of up to 500kN (@273mm diamter) and 350kN (@220mm diameter). The piles will be driven through alluvial silts (SPT N values 0-1), through a medium dense... [3 replies]
I have a situation regarding a +/- 22'tall cantilevered retaining wall. The wall is approx. 40 years old and that the wall appeared to be "leaning". (that's what we were told) Current design criteria(i.e. active pressures)provided by the Geotech exceed th... [7 replies]
The following formula is presented in the IStructE green book "Manual for the design of RC building structures". It is used for calculating the min depth of an unreinforced mass pad. Can someone please give me an explanation as to where this comes from, w... [0 replies]
Can anyone help me in determining the hammer efficiency of a Junttan PM16 piling rig with a 4ton HHK3 hydraulic hammer. I'm trying to determine set calculations for a 1:3 Raking pile. I'm assuming there will be some loss in efficiency due to the rake. I n... [0 replies]
I'm trying to figure a way to install piers between a reinforced concrete grade beam above, and competent rock below. Reinforcing for the pier will be a single number 9 bar, doweled into the existing grade beam. After the bar is in place, I will have to p... [12 replies]
So what type of foundation would you build in a "small" sinkhole condition....or better yet (the house is already built), what kind of retrofit foundation have others used in the past? The geotech found a small sinkhole on the end of the property, but th... [3 replies]
Do you think the dubai rotating tower is achievable from an engineering point of view, is the technology available for it to be construct it todays age? What do you think is the best foundation for such a dynamic structure? A video:
Hi there, a timber deck has been put behind a 1m high retaining wall, I have to check the capacity of a this wall due to the new loading, I know how to get earth pressure, but how would you convert a point load from the deck post applied on the wall to a... [6 replies]
I am trying to calculate the settlement at the edge of a circular tank. The foundation comprises ground improvement with the inclusion of a ring beam beneath the tank wall. Normally I calculate the total settlement of the tank using the tank diameter(B).... [2 replies]
Does anyone have or know where I can find "Signboard Footings to Resist Wind Loads", Civil Engineering, 1966? Thanks in advance! svenseven@yahoo.com... [5 replies]
For pad foundations they usually take into acount soil parameters within 2B below the footing. When it is a raft foundation 2B becoming a great number. What would be the depth to consider for soil parameters. (Although for geotechnical investigation one m... [1 replies]
I'm providing geotechnical recommendations for a 72 foot diameter water tank 20 foot height. Site at ridge top. About 3/4 of the tank footprint will bear on moderately to slightly fractured sandstone bedrock, expected settlement negligible per borings to... [14 replies]
I am looking for a good reference on how to model the dissipation of the axial load in the wale into the wall of a rectangular earth retaining system. Thank you in advance for your help.... [6 replies]
I am proposing a axially-loaded 30-inch diameter drilled shaft adjacent to a tunnel wall. The drilled shaft is designed for end bearing of 5 tsf. The length of the drilled shaft will be 50 feet. The bottom of the tunnel is at a depth of 40 feet and the he... [18 replies]
I am working on the foundation reinforcement design that currently has a few rock anchors holding it in place, we need to add more micropiles (3" dia. DYWIDAG 150ksi bar). The original foundation drawing is pretty vague and does not have specs shown for t... [2 replies]
Does anyone have a reference for sheet piling designs for the case of differing soil layers. I was given an analysis that concluded there is 10- ft of granular soil, 10 feet of organics,and then 10-ft of soil that has a phi value of 24 deg and c = 500. I... [2 replies]
We are designing a restrained tied back wall where the footing is exposed, i.e. no toe active pressure to resist sliding. This design is temporary, while repair work is being done to the surrounding structure (including replacing an exisitng base slab tha... [2 replies]
Hey All, I'm a first time poster and beginning engineer. I was hoping to find someone with expertise in bulkhead design to review my methodology and to answer some questions on my design of a navy style bulkhead. I've been tasked with design of a navy sty... [6 replies]
I am designing a small timber post and lagging wall. The structure is holding back 5.5 ft of sandy silt with groundwater estimated at 2 ft below ground surface behind the wall. Ground surface at the toe of the wall decreases at a 5:1 slope; ground surface... [5 replies]
Hi all, I'm looking for alternative foundation designs for 70 ft tall poles resisting axial, lateral and moment at base. The soil is medium to dense silty sand with phi of 28 to 30 degrees. Also at one of the location of the poles, peat was found in betwe... [12 replies]
I am seeking peer opinion/discussion as to a statement that is presented in a book entitled "Aboveground Storage Tanks" by Philip E. Myers, in regard to calculating design loads for storage tank columns that are within the tank. The column baseplate would... [4 replies]
Hello I'm designing sole foundations for a heated building where the anticipated frost depth is only marginally above the foundation depth. Foundation depth is 900 mm and frost depth is 800 mm. I'm wondering if there's need for wing insulation (both consi... [1 replies]
I have native silty clay with a liquid limit ranging from 55 to 73, and plastic limits of 26 to 29. The consistency of the clay ranged from firm to very stiff with SPT "N" values ranging from 7 to 16. I am curious if this clay will heave on shallow footin... [7 replies]
Does anyone have any good reference material for grain bin storage foundations? I want to determine the vertical/lateral force distribution transferred to the footing by a corrugated ring connection with anchor rods to the foundation. After an extensive i... [5 replies]
I am designing a 40 feet drilled shaft wall in DFW located in Eagle Ford shale. There are some contradictions between some designs I have seen and it is not clear what long term strength parameters I should use as well as whether or not the apparent earth... [0 replies]
I am planning on excavating an area of 25m X 40m X 12m Deep There is a 8 storey building located approximately 3m away from the 25m side What precautations can / should be taken to prevent the pit from collapsing and the tall building from falling! Any a... [12 replies]
This is almost an embarrasing question as it is pretty basic but there are 2 questions here: 1.) See attached, have I derived the equations for shear and moment correctly based on the soil pressure distribution given by the ASAE design guide for shallow f... [0 replies]
I am designing a drilled shaft for the support of a transmission monopole. Threaded #18 bars act as anchors and longitudinal reinforcement. The pier is 9.5 ft in diameter and about 40 ft long. Soil layers and tower loading are such that a very large momen... [2 replies]
I am planning to excavate test pits for site investigation for a light structure. The soil tends to be granular. I will not have any test equipment and hope that by visualization I could suggest a conservative bearing pressure. Typically the ground water... [20 replies]
Trying to find out what levels of sulfate and chloride in soil would be considered a concern regarding chemical attack to foundation concrete. Any tables providing "degrees" of concern, e.g., "slight risk", "moderate risk", "high risk", etc.?... [6 replies]
Hello Engineers, I am a licensed engineer. I am looking to design a residential foundation for my parents new home and help them save money. The foundation will consist of perimeter footings with concrete masonry block foundation walls above. Within the f... [7 replies]
I just inspected a residence and the garage slab has settled 6 inches in the center of garage in a V-like shape. When the car is parked the bearing pressure and deflection coinicide at the centerline. Has anyone ever seen a 6 inch deflection? Any tips wil... [10 replies]
Hi, I'm attempting to calculate the size(mainly the depth)of a reinforced concrete pad that sits on ground with an allowable stress of 50KN/m2 and taking a load of 250KN. Also the size (mainly the depth) a steel spreader plate for the same design paramete... [7 replies]
Hello everyone I am new to this forum and new to stress analysis also. I want to know some basic concept behind stress analysis of system connected to tank. I hope there are two displacement are to be provided for nozzle, one is due to thermal movement an... [0 replies]
I want to design a cantiliver sheet pile excavation support system for a foundation. The foundation is 20m diameter and 4m deep, soils are sand for 3m depth and then medium dense clay. I have a graph that gives me an answer for sheet pile length and secti... [4 replies]
I have a project in which the owner would like to use geothermal heating and cooling for the building. Due to the limited space on site and soil conditions they are going with a raft foundation and will install the geothermal loops within the building foo... [4 replies]
At work i have been asked to design a foundation were vehicles drive over. The worst case is the vehicle wheel on the edge of the foundation. It is central in the other direction. The eccentricity is outside the middle third therefore 2/3 x Rv/x formula d... [2 replies]
Can anyone provide ballpark numbers for estimating the cost of CIP retaining walls? This particular wall is approximately 10 ft high x 130 ft long. It is in the southeastern U.S. Not sure if it makes a difference for cost, but it is for the residential se... [7 replies]
Hi All, I am involved with an interesting project..... A client wants to build light structures for energy generation on large 40+ hectare area 60m high decommisioned gold tailingsdams (slimesdams). The dams have only recently been decommisions and althou... [14 replies]
I am trying to apply the "Apparent Earth Pressure Diagram" in Figure 8-28-2 of the AREMA Manual for Railway Engineering. The diagram is a trapazoidal shaped pressure diagram for a multi prop temporary wall. The diagram has a formula "F(H+SC)" to define th... [10 replies]
I'm designing a foundation for a fan. I'm planning on using ACI 351.3R-04 as the main guidleline for this design. ACI discussed five (5) common procedures for estimating dynamic forces for rotating machinery. My question deals with the last method, shown... [2 replies]
My background is general civil, but I have worked into doing more retaining wall design lately. Please excuse me if this is a simple geotech problem. I am looking to design a wall to retain less desirable fill material (low phi angle and ignore any cohesi... [10 replies]
Hey again ole friends...is good to have a few minutes these days to read through the posts. I'm in search of a reference I've seen before and I'm pretty sure it came from the regulars here (BigH maybe). It was a lengthy reference (maybe USACE or similar..... [2 replies]
