5,450CY Foundation Pour at Courthouse Commons

At 5AM on May 22, Cemex and Associated readymix trucks began delivering loads to the Courthouse Commons jobsite in downtown San Diego. The site is caddy-corner from the Central Courthouse between W. Boardway and W. C Street. Once on site, five truck mounted boom pumps moved the readymix 50 ft. below street level to the foundation. Pumps ranged in size from 46 meters to 61 meters and were lined up along Union and Front Streets. The deepest part of the foundation was 14.5 ft. deep at the elevator pits. Pumping at a peak of 600CY/hour, the pour lasted 11 hours with the last finisher going home around 8PM. In total 5,450 cubic yards were placed by a 30-man placing crew, 20 finishers, 10 pump operators and a support group of 40 individuals.

Looking ahead, the next major milestone will be the placement of another mat foundation of 6,650CY on July 5. If all goes according to plan general contractor Holland Partners expects concrete to top out in April 2023. The project is designed by Carrier Johnson architects and Bryson Markulim Zickmantel structural engineers. The building is 44 total levels including five levels of below grade parking and the roof deck. Commercial retail space is located on street level with the following seven levels dedicated to office space. The next 28 levels will hold 431 residential units, 87 of which are subsidized for low income renters. Once completed the Courthouse Commons will be among the top five tallest buildings in San Diego.

Autography Collection / Residence Inn Set to Top Out in Oakland

The Autograph Collection / Residence Inn dual brand hospitality tower by Marriott tops out next month in Oakland, CA. The project is located along Jefferson between 14th and 15th St. in the Uptown District surrounded by restaurants, entertainment and nightlife. With a total of 275 guest rooms the 207,000gsf structure is spread across one level below grade and 19 levels above including the roof deck. The Residence Inn rooms occupy levels 3 to 11 with Autograph Collection units on the upper floors.

A mat foundation pour kicked off the concrete scope with a total of with a total of 1107.5CY. The pour began at 3 AM and the last finisher went home at 9 PM. 115 readymix truck loads were pumped through three truck mounted boom pumps averaging 109 CY per hour. Decks were formed with a Titan system and the concrete support self-climbing system was used to form the core. Typical deck pours averaged 1200sf and were pumped using a 30m placing boom.

The project was designed by Stanton Architecture and KPFF structural engineers. General contractor Millie & Severson, Inc. aims to have the building open for business during the Fall of 2021.

Landmark II Tops Out in West Los Angeles

The Landmark II residential tower topped out this month along Wilshire Blvd. with general contractor Matt Construction. Looking south from Wilshire Blvd. the new building stands behind the Landmark II commercial office building between Granville and Stoner Avenues. The 35 level above grade structure holds 376 units with four levels of below grade parking for 421 cars.

The parking levels tie into an existing structure which had to remain operational throughout construction. Underpinning, or the process of strengthening the foundations of an existing structure, was part of seismic retrofit of the parking levels which was necessary to re-route traffic and create temporary access. Demolition of existing beams to connect the two parking structures included the de-tensioning of PT cables, and the installation of micropiles and an internally braced raker system.

The walls of the two cores are the primary lateral resisting system which were formed with EFCO Plate Girders to maximize the tie spacing. The elevator core formwork is supported by a self-climbing Power Tower PT-100 system. For the elevated decks Largo chose to use PERI perimeter tables with titan shoring for the handset portion of the decks. Gensler and Saiful Bouquet are the architect and structural engineer for the project which is scheduled to open during the Fall of 2021.

(W)rapper’s Exoskeleton Taking Shape

At the corner of West Jefferson and National Blvd. Largo is pouring the concrete at the first building in southern California featuring an exoskeleton structural system with general contractor Matt Construction. The commercial building features two levels of below grade parking and 17 levels above for a total of 355,180gsf. While the decks in a typical structure are supported by internal columns, walls and beams, designers for the (W)rapper decided upon a system outbound of the decks to maximize leasable space and create one of the most unique looking buildings in the region. Eight steel bands act as the exterior columns and wrap around the building on the outside of the glass façade in an abstract design with no particular pattern.

Largo began work back in June 2019 with the placement of the 5,600CY mat foundation pour. A total of 560 readymix truck loads were delivered to the site starting at 11PM June 7 to six truck mounted boom pumps. Two of the pumps were at street level and four were driven down a temporary ramp into the pit two levels below grade. Two additional boom pumps were located at street level to receive loads and reduce traffic in the pit by pumping readymix down to the booms in the pit for final delivery. In total 134 individuals were involved in traffic control, delivery, pumping, placing and finishing of the foundation with the cement masons heading home at 6PM June 8.

Largo finished pouring the core late last year which is being constructed independently from the office decks. The core will house the elevators, restrooms and mechanical, electrical and plumbing shafts the while the metal decks will make up the office space. The core had to be constructed ahead of the tower to assist in the erection of the unique framing system. Designers Eric Owen Moss Architects and Arup structural engineers anticipate having the building complete during the forth quarter of 2021.

St. Teresa of Calcutta Tops Out in San Diego

The St. Teresa’s of Calcutta affordable housing project topped out on the corner of 14th & Commercial in downtown San Diego this month. Largo worked with Level 10 Construction on the 15 level high-rise and three level podium development which holds a total of 407 units, 270 of which will be used specifically to address homelessness. The 18′ high ground level will house commercial and retail space with a fitness area, community room, management offices, and courtyard on the second level. The superstructure is made up of 17,563CY of concrete creating 328,514sf which was poured over the course of nine months.

Limited laydown area and the adjacent Covid-19 vaccination site added to the logistical challenges of the downtown environment. A Peri core-wall system which sat on embeds and did not rely on trailer panels for support was used to form the core. This allowed our crews to close the entire core the day before the deck was complete and pour both vertical and horizontal elements at the same time. During the typical levels our teams were able to pour an 18,000sf deck every week to meet the aggressive schedule.

Named in honor of Mother Teresa the development’s two main partners are the San Diego Housing Commission (SDHC) and Father Joe’s Villages, Chelsea Investment Corporation. The development will remain affordable for 55-years for San Diegans with low-income or who are experiencing homelessness. Designed by Joseph Wong Design Associates and BWE Structural Engineers, the development is scheduled to be open during the third quarter of 2021.

Natiivo Tower Tops Out at 48 East Avenue

Largo Concrete topped out at the Natiivo tower in downtown Austin, TX earlier this month. Located at the edge of the rapidly growing Rainey Street District, the 442,668gsf building is 33 levels all above grade. The first nine levels of the building are dedicated to parking with 24 levels of residential above holding 248 units.

All units come fully furnished with hotel licensing and can be offered as short-term rentals with building management providing hotel-like services and amenities. In addition to on-site concierge, housekeeping and laundry services the building also features a 18,000sf open air terrace on the 10th floor and a rooftop pool with cabanas and fireplace seating areas.

In total Largo poured 20,000CY of concrete over the course of 15 months with 130,000 manhours. The building is designed by STG Design and Cardno Haynes Whaley structural engineers and general contractor AECOM Hunt expect to have the project complete during the summer of 2021.

Reach for the Stars!

The New Century Plaza Towers became the tallest buildings in Century City, CA this month when Largo Concrete topped out at level 46. In addition to constructing the twin towers simultaneously, Largo also retrofitted the historic Fairmont Hotel designed by world-renowned architect Minoru Yamasaki along Avenue of the Stars. Yamasaki was also responsible for the triangular shaped 44-story Century Plaza Office Towers located on the opposite side of the main thoroughfare. In an effort to pay homage to Yamasaki, design architect Pei Cobb Freed & Partners shaped the new towers as reuleaux triangles. A figure consisting of three circular arches, formed from the intersection of three circular disks, each having its center on the boundary of the other two.

Largo began construction during the summer of 2018 by pouring seven large mat foundations, two of which were we over 9,300CY. Limited access to the site meant much of the readymix for the large pours had to be piped in from Constellation Way to placing booms mounted on tower crane foundations. The first of these two pours utilized five truck mounted boom pumps and two placing booms to place 9,509CY over the course of 16 hours. The second large pour was even further from the street and required five placing booms and two boom pumps to place 9,367CY over 16 hours.

The first four levels out of the ground are dedicated primarily to 1,345 parking stalls and back-of-house facilities. Radius vehicular ramps and grand staircases exude the circles used to shape the reuleaux tower decks to come above. A 25’ tall radius transfer beam supports 30 columns opening up the loading dock space. Formwork supplier Peri USA assembled a temporary access bridge to deliver rebar from Constellation Way to the back of the site. In addition to reducing the amount of crane time the temporary bridge also minimized vehicular traffic along the privately owned Solar Way.

The twin towers rise from the exquisitely landscaped plaza level lined with retail shops and cafés for a pedestrian experience which continues through the hotel lobby to Avenue of the Stars. The towers were constructed concurrently with crews pouring a deck on alternate towers every two days. A custom PERI ACS 400 core wall, self-climbing interior system with gantry beams suspending the exterior formwork was used for the hexagonal-shaped core walls. A radius trolley trailer beam was suspended from the core climber to facilitate construction of the steel framing inside the tower lobbies. The entire system weighed over 360,000lbs.

A column mounted cocoon screen with attached roll-back column formwork enclosed the upper floors as they were being constructed which removed re-shoring and enhanced safety on the site. The perimeter column forms were designed so that they could be stripped horizontally, from underneath the deck, which allowed the deck formwork to be completed before the column forms were poured and stripped. Largo also self-formed the masonry scope of work placing 102,000 concrete masonry units throughout the building including the entire height of the core.

In an effort to ease the strain on vertical transportation between the two towers, teams utilized a temporary 60’ pedestrian bridge spanning the two structures beginning at level 30 and moving up to level 43 as the buildings progressed. This proved especially helpful once Covid-19 reduced the number of individuals in each manlift for social distancing measures.

When complete, the $2.5 billion revitalization project will be over 1 million square feet on the 6.13-acre site. The Fairmont Century Plaza will feature 400 hotel suites with 63 private residences on the upper levels and the towers will hold 290 luxury condominiums with multi-level penthouses. Largo Concrete will have worked 760,000 Man Hours placing 151,000 CY of Concrete! General contractor Webcor is working with Gensler and Harley Ellis Devereaux Architects and structural engineer Englekirk to have the development open during the summer of 2021.

Le Conté Apartments becomes UCLA’s Tallest Building

Largo Concrete topped out at the UCLA Le Conté Apartments this summer making it the tallest building on campus. The undergraduate student housing project is located at the corner of Le Conte and Gayley Avenue on the south side of the campus. The south building is 11 cast-in-place levels above grade and the north is 19. The overall project is 301,761gsf and will add 1,167 beds in 192 rooms. General contractor PCL Construction, Studios Architecture and Nabih Yousseff & Associates structural engineers are on track for temporary occupancy in the Winter of 2021.

Miro Towers Become the Tallest Buildings in San Jose

The Miro Towers became San Jose’s tallest structures this month when Largo poured level 29 at 291′ above street level! Located on the north side of E. Santa Clara Avenue between Fourth and Fifth, the buildings are across the street from City Hall which used to be the city’s second tallest structure. Miro will feature a total of 630 two and three bedroom units and 633 parking spaces.

Stressing Procedure

Transfer girders utilize four rows of post-tensioned cables which are progressively stressed throughout construction. The girders are located on level five above grade and are up to 72” wide by 64” deep! The additional rows of PT cables are spaced 6” apart and lay below a row of tendons which are stressed after placing level five. Upon completion of level ten the bottommost row is stressed, then the second from the bottom row is tensioned at level 15, ending at level 25.

Steinberg Hart Architects, DCI Structural Engineers, and general contractor Suffolk Construction are on schedule to have the Miro towers open early 2021.

UCSD North Torrey Pines Living and Learning Center Buildings Three & Four

Largo recently topped out on the North Torrey Pines Living and Learning Center at the University of California, San Diego. The project was designed by HKS Architect, Inc. and Magnusson Klemencic Associates is located on the southeast corner of North Torrey Pines Rd. and Muir College Dr. in La Jolla, CA. Largo’s scope only covered a portion of the overall development with buildings Three and Four consisting of 15 and 14 levels respectively, for a total of 600,000gsf. The development features 2,000 new beds for undergraduate students with related residential life space, new facilities for the Sixth College, social sciences, arts and humanities, dining and retail space, and 1,200 parking stalls. General contractor Clark Construction is aiming to have the development open for the Fall 2020 semester with a LEED Platium rating.