HomeMy WebLinkAboutParcel Map 23561-2 Parcel 23 Addendum Soils Report
March 7, 2024
Mahir Investments, Inc. CWE 2220384.04
2661 Pummelo Ct.
Escondido, California 92027
Attention: Mr. Chintu Patel
Subject: Addendum and Update Geotechnical Report
Proposed Self-Storage Facility, Assessor’s Parcel Number 910-272-002
Madison Avenue, Temecula, California
References: 1) Christian Wheeler Engineering “Report of Geotechnical Investigation, Proposed Self-Storage
Facility Assessor’s Parcel Number 910-272-002, Madison Avenue, Temecula, California”, dated
September 23, 2022 (CWE 2220384.01)
2) Christian Wheeler Engineering “Preliminary Storm Water Infiltration Feasibility Study, Proposed
Self-Storage Facility Assessor’s Parcel Number 910-272-002, Madison Avenue, Temecula,
California”, dated September 26, 2022 (CWE 2220384.02)
3) Christian Wheeler Engineering “Response to Third-Party Geotechnical Peer Review, Proposed
Self-Storage Facility Assessor’s Parcel Number 910-272-002, Madison Avenue, Temecula,
California”, dated November 28, 2022 (CWE 2220384.03)
Ladies and Gentlemen:
In accordance with your request, we have prepared this updated geotechnical report to for the subject project.
This report has been prepared as an addendum to our referenced geotechnical reports. As such, unless specifically
modified or addressed herein, all of the findings, conclusions, and recommendations presented in the above
referenced reports remain applicable.
PRELIMINARY SITE INFORMATION AND PROJECT DESCRIPTION
The subject site is an undeveloped commercial lot, identified as Assessor’s Parcel Number 910-272-002,
which is located adjacent to and northeast of Madison Avenue, Temecula, California. Topographically, the
site is characterized by a relatively level pad with an elevation of about 1052 to 1055 feet. An engineered slope
CHRISTIAN WHEELER
E N G I N E E R I N G
Geotechnical & Geological Consulting ✦ Materials Inspection & Testing ✦ Building Envelope Consulting ✦ Laboratory Services
www.christianwheeler.com ✦ info@christianwheeler.com ✦ (619) 555-1700
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CITY OF TEMECULA
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valerie.caragan 04/04/2024
04/04/2024 04/04/2024
04/04/20
CWE 2220384.04 March 7, 2024 Page No. 2
up to approximately 10 feet in height ascends from the northeast perimeter of the lot at an approximate
inclination of 2:1 (horizontal to vertical) to the Interstate 15 Freeway. The site was mass graded approximately
30 years ago and review of the referenced aerial photographs indicates that the site was first used for
agricultural purposes since at least the 1930s. As noted during our surface reconnaissance of the site
conducted on March 7, 2024, the current site conditions are generally the same as they were at the time of our
field investigation and the preparation of the above refenced geotechnical report (CWE, 2022a).
We understand that the subject project will consist of the construction of an approximately 28,000-square-foot,
four-story, concrete and/or masonry structure with parking and drive areas. The self-storage building and
associated improvements are expected to be supported by conventional shallow foundations and the structure will
have a concrete slab-on-grade floor. Planned site grading is expected to consist of cuts and fill less than five feet
from the current grades. As part of the storm water management for the project two bio-retention basins have
been proposed within the northerly and southerly portions of the site.
CONCLUSIONS
In general, it is our professional opinion and judgment that the subject property is suitable for the construction of
the subject project. The recommendations contained in the referenced report remain applicable unless superseded
by the recommendations contained herein.
RECOMMENDATIONS
SEISMIC DESIGN FACTORS
Updated Seismic design parameters were determined in accordance with Chapter 16 of the 2022 California Building
Code (CBC) and the applicable sections of ASCE/SEI 7-16 Minimum Design Loads and Associated Criteria for Buildings
and Other Structures. For the subject site, correlated shear wave velocities measured/estimated in our CPT-1
indicate that the upper 100 feet of geologic subgrade can be characterized as Soil Site Class D (CWE, 2022a). It
can be noted that sites underlain by liquefaction-susceptible soils should be designated as Soil Site Class F,
requiring a site response analysis. However, as discussed in Section 20.3.1 of ASCE/SEI 7-16, for structures
having a fundamental period of vibration equal to or less than 0.5 second, it is not required to perform a site
response analysis and the site classification can be determined based on the code. We anticipate that the
proposed structures will have a fundamental period less than 0.5 second and can therefore be designed using
Soil Site Class D as described above.
CWE 2220384.04 March 7, 2024 Page No. 3
In accordance with Section 11.4.8 of ASCE/SEI 7-16, structures on Soil Site Class D or E sites that have a
mapped MCER spectral response acceleration parameter (S1) value greater than or equal to 0.2 require a site-
specific ground motion hazard analysis or the seismic response coefficient (CS) must be adjusted to
adequately characterize the site response (Exception 2). As noted in the Commentary for Section 11, “In
general, this exception effectively limits the requirements for site-specific hazard analyses to very tall and or
flexible structures at Site Class D sites.” The following Table I presents the updated seismic design
parameters based on Exception 2 in Section 11.4.8.
TABLE I: CBC 2022/ASCE 7-16 – SEISMIC DESIGN PARAMETERS
CBC – Chapter 16 Section Seismic Design Parameter Recommended Value
Section 1613.2.2 Soil Site Class D
Figure 1613.2.1 (1) MCER Acceleration for Short Periods (0.2 sec), Ss 1.578 g
Figure 1613.2.1 (2) MCER Acceleration for 1.0 Sec Periods (1.0 sec), S1 0.589 g
Table 1613.2.3 (1) Site Coefficient, Fa 1.000
Table 1613.3.3 (2) Site Coefficient, Fv 1.711
Section 1613.2.3 SMS = MCER Spectral Response at 0.2 sec. = (Ss)(Fa) 1.578 g
Section 1613.2.3 SM1 = MCER Spectral Response at 1.0 sec. = (S1)(Fv) 1.008 g
Section 1613.2.4 SDS = Design Spectral Response at 0.2 sec. = 2/3(SMS) 1.052 g
Section 1613.2.4 SD1 = Design Spectral Response at 1.0 sec. = 2/3(SM1) 0.672 g
Section 1613.2.5 Seismic Design Category D
ASCE 7-16 Fig. 22-14 Mapped Long-Period Transition Period, TL 8 sec
Section 1803.2.12 PGAM per Section 11.8.3 of ASCE 7 0.73 g
Probable ground shaking levels at the site could range from slight to moderate, depending on such factors as the
magnitude of the seismic event and the distance to the epicenter. It is likely that the site will experience the effects
of at least one moderate to large earthquake during the life of the proposed improvements.
CLOSURE
If you have any questions after reviewing this letter, please do not hesitate to contact this office. This opportunity
to be of professional service is sincerely appreciated.
Respectfully submitted,
CHRISTIAN WHEELER ENGINEERING
David R. Russell, C.E.G. #2215 Shawn Caya, R.G.E. #2748
DRR:scc:drr
ec: chintupatel80@gmail.com; dcamargo@noaainc.com; jch@noaainc.com